DEPARTMENT OF AGRICULTURE

DIRECTORATE OF

ANIMAL HEALTH

ANNUAL REPORT

1 APRIL 1993 TO 31 MARCH 1994

DIRECTORATE OF ANIMAL HEALTH PRIVATE BAG X138

PRETORIA 0001 TEL: (012) 319 6000 FAX: (012) 329 0499

CONTENTS INTRODUCTION CONTROLLED DISEASES Foot-and-mouth disease Tuberculosis Brucellosis African swine fever Rabies Corridor disease Anthrax Bovine malignant catarrh Sheep scab Johne�s disease African horse sickness Newcastle disease Salmonella enteritidis NON-CONTROLLED DISEASES Bacterial diseases Brucella ovis Bacteroides nodosus (foot rot) Dermathophilus congolense and Staphyloccus aureus (strawberry feet) Clostridium infections Corynebacterium infections Leptospirosis Campylobacter uppsaliensis in dogs Salmonella typhimurium Pasteurella multocida Uterine swabs of mares Escherichia coli Bolo disease Viral diseases Bluetongue Lumpy-skin disease Ovine contagious pustular dermatitis (orf) Three-day stiffsickness Maedi-visna Encephalomyocarditis virus Rickettsial disease Cowdria ruminantium (heartwater) Protozoal diseases Anaplasmosis Babesiosis (redwater)

Coccidiosis POULTRY DISEASES Salmonellosis Pasteurella multocida OSTRICH DISEASES Paramyxovirus enteritis (not Newcastle disease) Wesselsbron virus Virus hepatitus Mycoplasma spp. Clostridium perfringens (necrotic enteritis) Other problems in ostriches INTERNAL PARASITES Haemonchus contortus (wireworm) and Paramphistomum (conical fluke) INTERNAL PARASITES Dirofilaria sudanensis Parafilaria denticulata POISONING Enzootic geophagy (Vryburg hepatosis) Endophyte poisoning Lasiospermum bipinnatum poisoning (ganskweek) Tribulus terrestris poisoning (geeldikkop) Other toxic plants Ionophore poisoning Algae poisoning Urea poisoning Cardioglycocides DEFICIENCIES AND IMBALANCES Goitre Osteochondrosis Copper and zinc Cerebrocortical necrosis (thisamine deficiency) DISEASES OF OTHER ANIMALS Otter Marmoset Penguins Koi fish Tortoises

APPLIED RESEARCH AND PROBLEM INVESTIGATIONS Mutation rate of foot-and-mouth-disease virus in carrier buffalo Epidemiology of African horse sickness Tuberculosis: development of a reliable skin test in buffalo Lumpy-skin disease in buffalo Survival of foot-and-mouth-disease virus in impala carcasses Survey of redwater and anaplasmosis in the Dundee state veterinary area REPRODUCTION Necrotic balanoposthitis and vaginitis Vibriosis (Campylobacter) and trichomoniasis Epididymitis Ram tests AI-training PERMITS ISSUED FOR IMPORTS: HEAD OFFICE FINANCES LABORATORY SERVICES LIAISON WITH FOREIGN COUNTRIES Visits to foreign countries Visitors from foreign countries LIVESTOCK CENSUS 1993/94 LEGISLATION ANIMAL HEALTH SUPPORT SERVICES DISTRIBUTION OF VETERINARY OFFICES AND LABORATORIES ADDRESSES OF REGIONAL DIRECTORS, STATE VETERINARY OFFICES AND VETERINARY LABORATORIES

INTRODUCTION

No serious outbreaks of controlled animal diseases occurred during the year. Only Newcastle disease occurred widely in chickens as well as ostriches. A single outbreak of foot-and-mouth disease was diagnosed in impala in the Kruger National Park. Rabies continues to be a serious problem in KwaZulu/Natal despite extensive information actions and vaccination campaigns in the area. An increased occurrence of the disease in the South Eastern Transvaal is probably connected to the spread of the canid rabies virus from KwaZulu/Natal and also possibly from Swaziland to the neighbouring areas. The drought of the previous year under review continued in certain areas and caused serious losses, especially in the Northern Transvaal and the Kruger National Park. A marked decrease in game numbers occurred in the Kruger National Park � especially in buffalo (48%), warthog (57%) and roan antelope 35%). A marked increase in the applications for the importation of animals and animal products was experienced after easing of sanctions and the resultant access to international trade. Several veterinary delegations visited the country during the year, including the most important, an inspection visit of an European Union (EU) delegation to determine the acceptability of animals and animal products for export from South Africa to the EU. The first group of registered students for the National Diploma in Animal Health, will complete their course next year when approximately 52 students will receive their diplomas. Pioneering work has been done by instituting of the course. Consequently the Directorate received a national award for maintaining a high standard in distance training. Key posts, which have become vacant as a result of, for example, promotions have not been filled because of uncertainty about the final restructuring of the Department. Only a limited number of posts for animal health technicians, as well as the posts at the administrative control structure at the regional offices and laboratories, could be instituted.

CONTROLLED DISEASES

Foot-and-mouth disease The Kruger National Park and the adjacent game reserves are the only areas in South Africa where foot-and-mouth disease occurs endemically. Control measures are aimed at preventing the spread of this virus to neighbouring farming areas. The most important control measure in these adjacent areas is the vaccination of cattle (twice a year) and small stock (once a year), as well as the intensive inspection of stock in the controlled areas. A single outbreak of foot-and-mouth disease occurred in the Kurger National Park in impala near Tshokwane. Five clinical cases were shot and the SAT-2-virus was isolated from epithelium. Minimal spread of the disease occurred. The western border of the Klaserie, Timbavati and Sabi Sands Reserves now forms the foot-and-mouth disease control fence. This fence is inspected weekly by personnel from the Directorate. The old fence between the Kruger National Park and the Manyeleti and Buffelshoek reserves is still maintained by the Directorate. There is still strict control over the movement of cloven-hoofed animals and products derived from such animals. During November 1993, 42 buffalo were moved illegally from the Klaserie and Hoedspruit areas to farms in the Warmbaths and Thabazimbi areas. These farms, as well as neighbouring farms, were placed under quarantine.

Inspections of stock and game were carried out weekly. The 42 infected buffalo, as well as 6 buffalo from Addo with which they had been in contact, were returned to a farm in the Hoedspruit area. The buffalo were sampled for foot-and-mouth disease, as well as corridor disease. The buffalo were found to be infected with 3 strains of foot-and-mouth disease which occur in the Lowveld, namely SAT 1, SAT 2 and SAT 3. Fortunately, the disease did not spread to cattle. Tuberculosis At the end of the year under review, only 29 herds were still infected with bovine tuberculosis or subject to controlled movement. A total of 6 367 herds have been tested for this disease in terms of the bovine tuberculosis scheme. This represents 607 760 cattle, compared to the 702 238 cattle which were tested the previous year. In the 29 infected herds, 352 positive and 193 suspect cases were identified by means of intradermal tests (of which 210 cattle belonged to a single herd).

Certificates of accreditation were issued to 118 herds (210 herds in 1992/1993), while 1 820 herds were declared disease free in terms of the maintenance scheme (2 916 herds in 1992/1993). The status of tuberculosis in buffalo in the Kruger National Park remains unchanged, with the infection still confined to the area between the Olifants and Crocodile Rivers. No culling could be done during the year, as a result of the sharp decline in buffalo numbers, which prevented further surveys on the incidence of the disease. Only 36 buffalo were randomly culled on the Mlondozi plains, of which 9 showed macroscopic lesions.

Brucellosis During the year, 1 545 infected herds were tested for bovine brucellosis, while 505 previously infected herds have been declared brucellosis free. A total of 1,22 million serological tests, of which 1,8% were positive, have been carried out. Only 24 herds (10 804) have been officially vaccinated this year with the diluted Strain 19 vaccine.

Certificates of accreditation have been issued to 170 herds (26 548 cattle), of which 66 herds were declared disease free based upon results of the milk ring test. Declarations have been issued with regard to 6 011 herds (511 407 cattle) which had been declared free from brucellosis. New infections are discovered continuously, despite the fact that 505 previously infected herds have been declared free from brucellosis. The 1 545 infected herds represent an increase of 524 herds compared to last year�s figures. African swine fever Two outbreaks of African swine fever were diagnosed. In the Rustenburg state veterinary area, 3 pigs died and 6 pigs were destroyed, possibly after young pigs had roamed outside and had had contact with tampans. Eight pigs died and 33 were destroyed in the Ellisras state veterinary district, possibly after carcass material from slaughtered pigs had landed in the pigsty. Compensation amounting to R7 400 was paid to owners for the pigs which had to be destroyed.

Rabies A total of 606 cases (608 in 1992/1993) were diagnosed in several different animal species, including 42% in dogs, 25% in cattle, 12% in yellow mongoose (Cynictis penicillata) and 21% in other species. Allerton Veterinary Laboratory diagnosed 173 cases, while 487 cases were diagnosed at the Onderstepoort Veterinary Institute. The high incidence of the disease in dogs in KwaZul/Natal continues to be of concern, despite intensive attempts in the area to create a public awareness of the dangers of the disease and the precautionary measures which have to be employed. The spread of the disease in a southern and western direction is also a cause for concern and more cases than before have been diagnosed in areas which were traditionally rabies free. The canid rabies virus has also spread during the past year under review from KwaZulu/Natal (and also possibly Swaziland) to the South-Eastern Transvaal and is also now present in the Piet Retief district.

Information actions have been undertaken on a large scale, especially in the Natal area. Amongst others, colour slide and video shows on the disease have been presented at 238 schools in Natal. Several surveys have been carried out in the area to determine the number of dogs vaccinated, the distribution of the age and sex of vaccinated dogs and the reasons for public resistance to vaccination.

An international rabies symposium, which was attended by 180 delegates from 4 continents, was presented on 29 and 30 April 1993 in Pietermaritzburg. The symposium was followed by a scientific workshop on rabies which was held at the Onderstepoort Veterinary Institute. The conference was preceded by a 3-day workshop on laboratory procedures and basic diagnostic methods for rabies. The workshop was attended by 28 delegates from Southern and East African countries.

The symposium was followed by a scientific workshop on rabies which was held at the Onderstepoort Veterinary Institute. The conference was preceded by a 3-day workshop on laboratory procedures and basic diagnostic methods for rabies. The workshop was attended by 28 delegates from Southern and East African countries Corridor disease One outbreak occurred on a farm in the Warmbaths district after Lowveld buffalo had been moved illegally from the controlled red-line area. Ten cattle from a group of 67 showed typical clinical and postmortem changes. The diagnosis was confirmed by the Onderstepoort Veterinary Institute by means of organ smears. Cattle in the area are still being dipped every 3 weeks to control the infected brown ear tick (Rhipicephalus appendiculatus). Anthrax It is estimated that less than 15% of all cattle have been vaccinated against anthrax this year. These figures are a cause for concern, especially when considering that 2 outbreaks occurred this year outside the Kruger National Park.

Ten kudu died on a game farm near Ellisras, adjacent to the Thabazimbi district, 4 cases of which had been confirmed. Large numbers of vultures might have played a role in the transmission. Three horses of the South African Defence Force died in Potchefstroom due to anthrax. These horses showed typical colic symptoms. Subsequently 887 horses were vaccinated against anthrax.

Bovine malignant catarrh Bovine malignant catarrh was removed from the list of controlled diseases in December 1993 after several months of negotiations between the Directorate, the South African Agricultural Union and other industry organisations. The amended measures include, amongst others, that the movement of blue wildebeest is no longer controlled by the Directorate. Eighteen outbreaks of bovine malignant catarrh in cattle, involving 44 deaths, occurred. Blue wildebeest were involved in all cases, except in 1 case. Sheep associated bovine malignant catarrh was confirmed in 1 heifer in the Paarl district.

Sheep scab Amendments to the regulations during the past year delegated the responsibility for the control of sheep scab to the stock owner: The Directorate will, however, still confirm the diagnosis and also be responsible for extension and law enforcement.

This may be the reason why fewer cases of sheep scab have been reported or located this year. Only 523 outbreaks have been confirmed, in which 95 401 sheep were visibly affected. In the Transkei 134 of these outbreaks occurred with 13 338 sheep affected.

Johne’s disease Johne�s disease has been scrapped as a controlled disease during the year and currently only notification of any occurrence or suspected occurrence is compulsory. Mycobacterium paratuberculosis was isolated from an imported Limousin cow and in 2 outbreaks in sheep. Seven clinical cases were destroyed at the Nooitgedacht Agricultural Development Centre and the diagnosis was confirmed by histopathology by the Onderstepoort Veterinary Institute. This disease was confirmed for the first time in a flock of sheep outside the Transvaal. A serious outbreak occurred in a flock of sheep in the Caledon district. All investigations show, however, that the disease has probably been present in the flock for more than 5 years. Signs of loss of mass and a moderate intermittent diarrhoea were first noted in ewes 4 tooth and older. Help was only called in when the symptoms appeared by young 2-tooth ewes. Diagnosis and control of the disease continue to be a problem. African horse sickness A few isolated cases of horse sickness occurred in unvaccinated animals. Problems experienced with the Onderstepoort horse-sickness vaccine have led to several mortalities. Two foals of 1 year old died 10 and 12 days after vaccination, respectively. The vaccine was subsequently temporarily withdrawn from the market. No further problems have been experienced, after modifications by Onderstepoort. The incidence of horse sickness was higher than the previous year, as a result of good rains and favourable conditions for insects. A total of 19 horses were affected in 10 outbreaks compared to 5 outbreaks (7 horses) the previous year. A protocol has been supplied to the European Union (EU) during the year under review in which an application is made to declare the Cape Peninsula a horse-sickness-free area. It has been suggested that vaccination against horse sickness be prohibited in this area and that there should be strict control on movement of horses to and from the area.

If carried through, all mortalities in horses will have to be reported and these mortalities will be subjected to postmortem examinations. The establishment of an insect-free quarantine station in this area will make it possible to certify horses as free from horse sickness and to move them to the EU and the rest of the world. Newcastle disease The first outbreak of Newcastle disease during the year under review occurred in June 1993 in chickens near Brits. Subsequently a total of 61 outbreaks occurred in poultry over a wide area, involving a total mortality of 177 354 chickens. Several Serious outbreaks occurred in Natal in an area where approximately 40 million broilers are produced per year. Large numbers of chicks died and were buried, only to be dug up during the night and to spread the disease throughout the area. The high mortalities were caused by a velogenic strain of the disease. Several outbreaks have also been confirmed in ostriches since July 1993. The symptomatology of Newcastle disease in ostriches differs slightly from that in chickens. Ostriches primarily show nervous symptoms and swelling of the head and neck. Young chicks die peracutely. Vaccination with a combination of the living virus and the inactivated vaccine has been recommended. The Newcastle disease vaccines are not registered for use in ostriches, and trails are therefore still continuing to determine the most effective vaccination schedule.

Control measures have also been instituted to ensure that ostrich meat destined for export, is derived from ostriches which had been vaccinated against Newcastle disease.

Export measures Feedlots for slaughter birds with a view to export measures are approved and registered by the state veterinarian. The following control measures apply: • No breeding units and other poultry within 1,5 km. • No contract with other ostriches which are not of the same health status. • Monitoring of the area within 10 km specifically for Newcastle disease and

ostrich influenza. Ostriches are identified on arrival, registered (name, address of origin, date, number, age, identification numbers, vaccination date, and date of despatch to the abattoir), and vaccinated against Newcastle disease with an inactivated vaccine. Newly vaccinated ostriches are kept separate for 14 days. Ostriches only qualify for slaughter for export purposes 30 days after vaccination and after a stay in an officially registered feedlot which is under the supervision of a state veterinarian. Movement to the feedlot and from the feedlot to the abattoir also takes place with the permission of the state veterinarian (movement permit). Only ostriches which will produce meat suitable for export are slaughtered at the abattoir on a particular day. Approved, registered feedlots are continuously monitored and all mortalities examined and the diagnoses recorded in a register. Salmonella enteritidis Salmonella enteritidis, which was isolated for the first time in December 1991 in young broilers in the Western Cape region, was widespread in this area at the end of the previous year under review. The situation in the rest of the country was still unclear. Only phage type 34 had been identified at that stage. Strict import control measures had been instituted with regard to the importation of poultry products and meat to prevent other phage types from entering the country. During the current year under review, 9 outbreaks occurred. A total of 8 418 cases have been reported and 372 mortalities had occurred . Phage types 34, 2 and 4 have been identified. The first outbreak of Salmonella Enteritidis in the Eastern Cape was confirmed during the current year under review. Mortalities (60) occurred in a group of 300 3 to 4 week old chicks.

Three outbreaks in Natal, as well as the outbreak in the Eastern Cape originated from a breeder in the Transvaal. The Natal Poultry Institute (NPI) established a control and monitoring system subsequent to the outbreaks in Natal. One outbreak of the disease also occurred in the Orange Free State. Salmonella enteritidis therefore seems to be well established in South Africa. An integrated approach is currently followed to decrease Salmonella enteritidis infection. It has been declared a controlled disease and all outbreaks, or suspected outbreaks have to be reported to the nearest state veterinarian. Import control measures with regard to day-old chicks have been tightened and breeder flocks from which day-old chicks originate, have to be confirmed to be Salmonella enteritidis free by means of serology tests (ELISA) and bacteriology (hatching eggs). The prevention of infection has to be further accomplished by maintaining by hygiene and by means of effective disinfection of housing facilities, biosecurity and the decontamination of feed. Vaccines can be used as an additional measure to protect breeder flocks. An inactivated Salmonella enteritidis vaccine has been registered for use in South Africa, while 2 live Salmonella typhimurium mutant vaccines have been allowed experimentally under strict control. Monitoring programmes involve hatcheries, breeder flocks, commercial flocks as well as abattoirs and include serological tests and bacteriological cultures.

NONCONTROLLED DISEASES Bacterial diseases Brucella ovis In a selective survey in the state veterinary areas of the Western Cape,

Free State, Highveld and the Transvaal, the folloing observations were made:

Data was obtained from 1 121 completed questionnaires. 1 024 ram herds

were clinically examined and 11 179 serological tests were carried out. • 24,4% of the herds tested positive. • 6,8% of all rams tested positive. • Geographically the majority of positive cases were recorded in the

Eastern Transvaal, Southern and Western Free State, North-Western Cape and the Karoo.

• Significantly more of the Dorper herds as well as Dorper rams proved to be positive (17,7% of Dorper rams) in comparison with 6,7% positive among Dohne Merino rams.

• According to the results and replies to the questionnaires it was deducted that the use of Rev 1 vaccine did not make any difference in the occurrence of Brucella ovis infection. It could, however, also signify the fact that many herds where Brucella ovis were diagnosed, only recently introduced a vaccination programme and that differences will only come to light in a few months� time. Incorrect use of vaccine also contributed to the bad results.

The correct use of the Rev 1 vaccine should thus be actively propagated.

Bacteroides nodosus (foot rot) Because of widespread damp weather during the past summer, the

occurrence of foot infections, lamenesses and foot rot were of a higher order than the previous year. A ram from Natal, infected with Bacteroides nodosus, was introduced into a flock in the district of Bethlehem. Very soon the whole herd was infected and the owner had to cull 100 ewes. The diagnosis has been confirmed by Onderstepoort Veterinary Institute.

Dermathophilus congolense and Staphylococcus aureus (strawberry

feet) Arthritis caused by this condition was diagnosed on a farm in the district of

Middelburg, Cape in 136 lambs out of a group of 146 individuals. They developed, within a period of 2 weeks, infection of the coronary band. It spread within a very short period, causing swollen joints with subsequent acute lameness.

Clostridium infections • Clostridium botulinum At Potgietersrus 12 guinea-fowl died after ingesting Clostridium botulinum

toxin. • Clostridium perfringens Several outbreaks have been reported throughout the country. In 3

instances it was caused by contamination of drinking water by organic or carcass material.

Piketberg : 16 out of 150 dairy cows died Paarl : 12 out of 50 sheep died Swellendam : 50 out of 150 sheep died Bredasdorp : 20 out of 50 ostriches developed paralysis

(an ostrich carcass was found in the drinking trough). The toxin was identified and the correct antiserum was administered to all affected birds. All recovered but one.

A 700-sow unit in the district of Paarl experienced a preweaning mortality

rate rising from 6 to 15%. These fatalities were caused by a Clostridium perfringens infection. This herd previously experienced problems with clostridial enteritis. As a set routine sows are now vaccinated, prior to mating, with the Onderstepoort vaccine against lamb dysentery (Clostridium perfringens type B). This vaccine gives a cross protection against type C, which caused problems in the past.

Clostridium perfringens (necrotic enteritis) occurred throughout the

Western Cape among ostriches. The majority of isolates were identified as type B although a few type A and a single type D were also identified.

Outbreaks of Clostridium perfringens were also diagnosed in 2 lorikeet

collections in the district of Cape Town. Mortalities in sheep throughout the country, caused by pulpy kidney (C.

perfringens) are still of an unnecessary high level and of great concern. In most cases the lack of a proper immunisation programme as well as the incorrect use of the different vaccines can be put down as the main reason for these mortalities.

Corynebacterium infections In the Beaufort-West district 26 lambs out of a flock of 153 died after they

had been vaccinated with an autogenous vaccine against orf, prepared by the local veterinary laboratory. The vaccine proved to be negative against any bacterial contamination. The absence of proper sterile techniques while administering the vaccine (syringes and needles) was definitely the reason for the problem (the pen and surroundings were highly positive to a variety of Corynebacterium spp.).

Corynebacterium ovis (pseudotuberculosis) abscesses occurred in a herd

of black wildebeest in the Wolwespruit Nature Reserve near Wolmaranstad. Abscesses were mainly located in the lungs and mediastinal lymph nodes.

Corynebacterium pyogenes was the reason for acute pneumonia/pleuritis

syndromes with accompanied abscessation and abortions during the 1993 lambing season on farms in the Grahamstown area.

Leptospirosis During April 1993, a calf in the Queenstown district developed typical

symptoms of redwater (red urine). The condition was subsequently diagnosed as leptospirosis and successfully treated with dihydrotreptomyncin. A few months later sows on the same farm, started to abort. Leptospira bratislava was isolated.

A vaccine against this organism was imported from Germany and for the

first time a vaccine of this kind was tested in the RSA with good success. The losses as a result of the abortions in the sow-unit, were estimated to between R1 million and R2 million. The sows were vaccinated twice with a monthly interval. Serological results which were measured against the decrease in abortions, will be published at a later stage.

Several cases of serologically positive cattle were diagnosed near

Humansdorp. Leptospira hardjo abortions among cattle in 6 different districts in the

Western Cape region, were serologically and/or bacteriologically confirmed. In most of the cases abortions occurred between the first 6 to 8 months of pregnancy. Good results were obtained with the leptospirosis vaccine.

Leptospirosis was serologically diagnosed at Groote Schuur Hospital in Cape Town, in a person hospitalised for a month with alveolar haemorrhage. The 3 dogs of this owner all showed titres of 1:1 280 against L. canicola. The dogs were immediately treated.

Campylobacter uppsaliensis in dogs In the dog unit at the Victor Verster Prison, Paarl, 17 out of 35 dogs

developed an acute enteritis after 2 dogs had been introduced into the kennels from the Transvaal. Bacterial isolates were positively confirmed as Campylobacter uppsaliensis by the Red Cross hospital in Cape Town. This organism causes enteritis in dogs and man in Europe. All dogs reacted well to treatment with a broad spectrum antibiotic.

Salmonella typhimurium Infection with this organism was diagnosed in several species where it

rarely occurs, e.g. a mature equine died as a result of an acute colitis; an aborted equine foal; a zebra foal died at 2 weeks of age with septicaemia; an outbreak of enteritis on a large scale and subsequent mortalities in growing pigs; necrotic typhlitis and colitis in ostrich chicks in the districts of Albertinia and Middleton, as well as an outbreak of encephalitis in ostrich chicks in the district of Wellington � all caused by Salmonella typhimurium infection.

Pasteurella multocida Serotype 3 of this organism caused large-scale mortalities in wild

waterfowl in the Cape Town region. The same serotype has been the cause of Muscovy ducks, kept for commercial purposes, dying peracutely. Ornamental ducks as well as broiler breeding flocks in the Kraaifontein district died as a result of serotype 4 and 10.

Uterine swabs of mares • Klebsiella 30 was isolated from uterine swabs in mares originating from

the Argentine and Klebsiella 6 were isolated in mares from Italy. • Streptococcus zoo-epidemicus were isolated in uterine swabs obtained

from mares coming from Australia and from the USA. • Pseudomonas aeroginosa was isolated from a uterine swab in a mare

from France.

Escherichia coli Several consignments of birds at the quarantine station at Jan Smuts

Airport were infected with E. coli Six Eclectus parrots out of a group of 12 died of E. coli infection and 41 out of 527 Senegal parrots from Guinea also died as a result of this infection.

Bolo disease During a meeting at Cathcart, arranged on behalf of the local Farmers�

Association, problems regarding bolo disease were discussed in depth.

Spread of infection: number of positive farms 1984 1993Cathcart 12 25Komga 0 0Stutterheim 25 33Queenstown (Tylden) 0 1Total 37 59

Available statistics showed that there was an increase of 60% in the

incidence of bolo disease during the 9-year period. The most effective control measure is still a combination of dipping and slaughtering of infected animals.

Viral diseases Bluetongue Good general rain during the summer, led to a higher incidence of

bluetongue in nearly all sheep-farming areas. On many a farm where bluetongue (and as a result mortalities) did occur it was remarkable that mixing of 3 factions of bluetongue vaccine took place prior to vaccination. This proved to be the reason for the low immune response in such flocks as all the strains were introduced simultaneously.

Lumpy-skin disease During the 3 seasons 1989/90 to 1991/92 the incidence of lumpy-skin was

relatively high. The higher incidence of the disease stimulated the sale of vaccines (see graph). The above-mentioned outbreaks followed on 2 previous years (1987/88 and 1988/89) during which the sale of lumpy-skin vaccine was rather low, with a subsequent increase in the susceptible population. During the 1992/93 season the incidence of lumpy-skin outbreaks decreased � partly as a result of the drought but also because of the positive immunisation programme the previous year. Vaccine sales during 1992/93 was, as expected, low and with the additional effect of the good rains experienced this year, there again was a higher incidence of disease. Vaccine sales really surged this year (±6 million doses because farmers tend to vaccinate animals only when there are reports of the disease). It also seems as if immunisation in many cases took place timeously, so many potential outbreaks were prevented.

Ovine contagious pustular dermatitis (orf) This remains a serious erosion disease in almost all the sheep-farming

areas of the country. In the Beaufort-West area 3 820 doses of an autogenous vaccine were prepared compared to 952 doses the previous year. As a result of the lack of regular active immunisation in most parts of the country, most flocks are highly susceptible, which seems to be the main reason for outbreaks, especially among young stock.

Three-day stiffsickness Widespread outbreaks did occur in the lower Albany and Bathurst district

with a 90% morbidity in some herds. Vaccine sales proved that a very low percentage of herds were vaccinated with the result that the majority of herds were completely susceptible to the disease. Although mortalities were low the effect of production losses, especially in dairy herds, was very high.

Maedi-visna In the Dorper herd of the Goedemoed goal near Fauresmith, attempts are

made by means of a cooperative trial to prevent the high incidence of lung disease experienced in this herd. Maedi-visna, as well as other lung conditions, e.g. jaagsiekte, are constant problems.

The herd is subjected to maedi-visna serological tests every 6 months and

all positive cases are moved to another herd which are in complete isolation from the negative herd. Apart from these 2 herds another herd is formed from ewe lambs born out of the negative herd.

At this stage it appears as if the best progress is made in the young

negative herd. The number of positive reactors declined from 36,9% in June 1993 to 18,8% in February 1994.

The number of positive cases in the adult negative herd remained more or

less constant at 48%. As the incidence of maedi-visna is very high in this herd, it was decided not

to cull all positive cases immediately. Certain culling criteria were decided on, e.g. mothering ability, udder problems, age, respiratory problems and emaciation, etc.

All culled animals are subjected after slaughtering to a complete

pathological examination. Progress made with the control of maedi-visna can therefore be monitored pathologically.

The results obtained on the culled animals since January to December

1993 can be summarised as follows:

Sheep culled : 636 Lung pathology : 208 (32,7% of sheep slaughtered) Maedi-visna : 68 (32,7% of sheep with lung pathology) Jaagsiekte : 29 (13,9% of sheep with lung pathology) Interstitial pneumonia : 54 (26% of sheep with lung pathology) Chronic purulent pneumonia

:

20 (9,6% of sheep with lung pathology)

Abscesses of lungs : 83 (39,9% of sheep with lung pathology) Many of the cases of interstitial pneumonia could be early cases of meadi-

visna. Corynebacterium ovis seems to be the most important pathogen isolated

out of the lung abscesses. Encephalomyocarditis virus This virus was responsible for the death of at least 40 elephants in the

Kruger National Park. Rodents are carriers of the virus and contaminate food and water via their excreta. The disease can also lead to the death of domestic pigs and primates. The Park experienced an explosion of the rodent population the past year which increased the risk of infection.

The Foot and Mouth Disease Laboratory is in the process of developing a

vaccine against the encephalomyocarditis virus. Progress reports in this respect are very positive.

Rickettsial disease Cowdria ruminantium (heartwater) Outbreaks still occur in great numbers throughout the heartwater endemic

areas in the RSA and neighbouring countries. The number of outbreaks reported are note a true reflection of the real incidence of the disease. Most cases are not brought under the attention of state veterinarians.

Protozoal diseases Anaplasmosis This disease is still causing widespread problems. Very few outbreaks in

relation to the real incidence of the disease were reported.

Babesiosis (redwater) Many reports of outbreaks throughout the country have been submitted.

Apart from the disease in cattle, quite a number of cases in horses and zebra have also been reported. The feedback on the incidence of redwater is also not satisfactory. Farmers are also reluctant to make full use of the available blood vaccines.

Coccidiosis Coccidiosis is normally associated with intensive farming conditions such

as feedlots such as feedlots and irrigated pastures. Several cases of coccidiosis were, however, reported in animals under natural veld conditions during the past season, most probably attributable to the higher than normal rainfall this year.

In the district of Montagu adult ewes on the veld were infected soon after

they arrived from Calvinia. They were most probably completely susceptible to coccidiosis as the hot dry climatic conditions in Calvinia are not conducive to the lifecycle of this parasite. Stress as a result of the transport over a long distance also attributed to a lower resistance to internal parasites. Mainly as a result of the abnormally wet winter in the Western Cape, the incidence of coccidiosis, even on natural veld, was very high.

On Robben Island the disease has been observed in springbok.

POULTRY DISEASES Salmonellosis This disease has once again been the main cause of mortalities in birds at the Jan Smuts Quarantine Station. It has been diagnosed in most of the consignments of imported birds. A total of 732 birds of several species died from this disease. Pasteurella multocida Mortalities have been recorded in several broiler flocks. An overseas vaccine, which was imported for experimental purposes, was used in replacement flocks where treatment had been unsuccessful. Water fowl appears to be particularly susceptible. Several diagnoses have been made on the Cape Flats. Cormorants were affected on Dassen, Malgas and Dyer Islands. The isolates were proved to be serotype 3 in all cases.

OSTRICH DISEASES

Several disease conditions have been diagnosed in ostriches, although not on a large scale. Paramyxovirus enteritis (not Newcastle disease) Caused several mortalities in the Oudtshoorn district. Wesselsbron virus This virus has been isolated from ostrich chicks on farms in the Oudtshoorn and Prince Albert districts, where high mortalities had been experienced. No characteristic pathology was observed, but an enlarged spleen was found in all cases. A survey carried out at the abattoir in Oudtshoorn, showed that the virus occurs widely. Further investigations are being carried out. Virus hepatitis Cases if cholangiohepatitis in ostrich chicks were investigated in a few districts in the Eastern Cape. Two virus isolates, which cause similar cytopathological effects in tissue culture, have been isolated in these outbreaks. The isolates have not been identified yet. Mycoplasma spp. Rhinotracheitis occurs commonly in ostriches raised in feedlots. Outbreaks are seen especially after sudden changes in weather conditions, accompanied by bad management, e.g. dustiness. Mycoplasma spp. have been isolated from these cases. These isolates could not be identified by the University of Liverpool as any known avian Mycoplasma spp. Attempts to artificially induce the syndrome have been unsuccessful. It would appear as if the condition is precipitated by unfavourable conditions in the feedlot, as it does not occur under optimal management practices. No Mycoplasma sp. has been isolated from ostriches which are free from respiratory disease. It has been possible to isolate the organism 3 months after experimental infection. Clostridium perfringens (necrotic enteritis) This disease occurred widely. On a farm in the Cape Town district, 25 out of 50 chicks died before the age of 3 months. Uncontrolled access to lush kikuyu grass and wireworm infestation were underlying problems.

Clostridium perfringens tupe B has been isolated in most cases. The Onderstepoort lamb dysentery vaccine was effective when used at an age of between 2 and 6 weeks. Other problems in ostriches Salmonella typhimurium, ostrich pox and �vrotmaag�, have been diagnosed. Internal parasites are increasingly becoming a problem, as a result of intensive farming practices.

INTERNAL PARASITES Haemonchus contortus (wireworm) and Paraphistomum (conical fluke) Wireworm and conical fluke caused extensive losses in especially smallstock. Fasciola spp. were responsible for mortalities and severe production losses among cattle in the summer rainfall areas. Resistance against internal parasites is becoming a very serious problem. The Directorate is involved with the very important work of the Worm Resistance Workgroup in this regard.

EXTERNAL PARASITES Dirofilaria sudanensis During December 1993, 14 out of 16 members of a pride of lions in the Kruger National Park, developed extensive areas of haemorrhagic dermatitis all over the body as if they were shot with a shotgun. Skin biopsies revealed an infestation of filaria worms. Parafilaria denticulata This parasite � a new species � has been recovered in buffalo showing ulcerative dermatitis during November 1993. Musca spp. act as intermediate hosts by taking u the eggs contained in the pin-point haemorrhages on the buffalo�s skin. It takes 14 days for the microfilaria to develop in the fly after which transmission to other buffalo can take place. Once in the subcutaneous tissue of the buffalo it takes 250 days or more (following summer) for the female to develop to the stage where she will be able to penetrate the skin for a new cycle to commence. It would appear as if Parafilaria denticulata is species specific.

POISONING

Enzootic geophagy (Vryburg hepatosis) A condition, where young calves ingest excessive amounts of soil, has been noticed for a number of years in the Reivilo region. About 50 400 ha are involved. the soil in the region is very rich in manganese which in turn inhibits the uptake of iron by the plants. Calves on farms with this problem, are apparently normal at birth but develop within days a severe pica as a result of a measurable deficiency in iron. The intake of vast quantities of this manganese-rich soil will inhibit the absorption of iron by the intestinal tract even further: Calves, as a result, become poisoned by manganese. As a result of the iron deficiency, anaemia and icterus develop as well as secondary infection of the intestine through the irritation caused by the intake of large quantities of soil. If the calves, for a period of 3 months, are prevented from taking in any soil, the problem seems to disappear. The toxic levels of manganese in the colostrum therefore act as trigger mechanism for this condition. Methods to determine the levels of manganese in colstrum are investigated. Endophyte poisoning In the district of Humansdorp an outbreak with typical symptoms occurred. The pastures concerned were mixtures of Clover spp. and Fescue spp. Animals shoed symptoms of heat stress even on the coldest of days, e.g. rapid shallow breathing, in creased body temperatures and decreased milk production (an average drop of 8ℓ/cow/day). The veterinary regional laboratory at Stellenbosch identified the following endophytes out of the pastures by means of the rose bengal test: • Perennial rye grass (Lolium) • Fescue spp.: in hay and fresh cuts • Finger grass or quickgrass: Tetrachne, cocksfoot Lasiospermum bipinnatum poisoning (ganskweek) In the district of Murraysburg 19 out of 30 beef heifers in calf died as a result of ingesting these plants. A few Angora goats were also affected. Tribulus terrestris poisoning (geeldikkop) Following the good rains in the Karoo large areas were covered by duwweljies. On a farm in the Beaufort-West area, 26 out of 83 lambs died as a result of �body dikkop�. This is the general name given by farmers to geeldikkop when swelling of head and ears do not occur, and only signs of icterus are present.

Other toxic plants Several mortalities in cattle, sheep and horses were reported following the intake of toxic plants: • Tulp • Lantana camara • Solanum kwebense (maldronksiekte) • Dipcadi glaucum (malkopui) • Senecio spp. Ionophore poisoning Within 24 hours after they had been exposed to a ration containing Romensin, 95 out of 120 stud Merino rams started to die. The farmer, in stead of adding 70 to 80 g of the product to the ration, added 6 kg. Algae poisoning In the Western Cape, 2 cases of algae poisoning have been reported during the warm summer months. In the district of Malmesbury 20 (4-5 months old) calves developed signs of photosensitivity a few days after they had been moved to a fresh camp with lucerne and where a new earth dam recently had been constructed. They were removed immediately and recovered completely. Two weeks later 70 dairy cows were put into the same camp after which 3 cows died acutely within 3 days. Postmortem findings demonstrated severe liver damage. A heavy growth of blue-green algae was present in the one corner of the dam (blown by the wind in that direction). It so happened that the corner with the algae was the only available drinking spot. The second case was confirmed near Darling. A group of 21 cattle and 249 sheep were put into 4 big stubble camps (±125 ha). About 2 months after they had been introduced, 5 adult cows died. The rest of the herd were immediately removed. Ten days later 28 sheep died in the same camp. Postmortem findings indicated severe liver necrosis and haemorrhage. Although the camps were equipped with proper drinking troughs, there were also in the one corner where a heavy growth of algae was present. It was partially fenced but a stretch of water full of algae, was still available for animals to reach. It would appear that initially, when grazing was still in abundance, animals grazed close to the water troughs but as grazing became scarse they moved further away from the water troughs and it became easier to drink in the vlei where they then ingested the algae.

The algae in the first outbreak was identified as an Anabaena sp. and that of the second outbreak as a Nodularia sp. Both of them produced a micocystine hepatotoxin. It was the first confirmed incidence of algae poisoning outside the Southern Transvaal and Northern Free State. The unusual summer weather probably played an important role in the onset of the condition. Urea poisoning Several cases of urea poisoning were confirmed throughout the country. The majority of cases proved to be as a result of home mixtures wrongly formulated by farmers and/or their workers. Rainfilled feeding troughs also caused problems as the animals consumed excessive quantities of urea dissolved in this water. Cardioglycocides A farmers from the Bathurst district lost 5 cows after they had been moved from grassveld to a bushveld camp. They died within 24 hours despite being treated after they showed signs of weakness. Postmortem examination revelaed typical signs of cardiac failure with extensive haemorrhages in the epi-, endo- and myocardium. Histopathological findings showed myocardial degeneration and necrosis typical of glycocide-poisoning. Quite large quantities of Bobaritia orientalis (Afrikaans � besembiesie) were found in the ruminal contents. This plant is related to tulp and slangkop (Ornithoglossum spp.). No information about the toxicity of this plant is available. It is very unpalatable and animals normally do not graze it readily. It could, however, have been the reason for the fatalities.

DEFICIENCIES AND IMBALANCES Goitre On a farm 10 out of 180 calves were born with extensive signs of goitre. Fowl manure was used as supplement to the normal diet of the cows. An iodine deficiency was confirmed in the cows. Osteochondrosis After a group of 12 Bonsmara bulls had been on an intensive feeding programme, 4 developed severe swellings of the hock joints. Osteochondrosis dissecans were diagnosed at slaughter.

Copper and zinc Survey in the district of Ixopo proved that only 2 out of 30 farms contained optimal levels of copper (516 serum samples were investigated). A total of 500 specimens were tested to confirm levels for the presence of zinc. Only 15 out of 29 farms proved to have optimal levels. It can therefore be assumed that copper as well as zinc deficiencies will occur in this district. Cerebrocortical necrosis (thiamine deficiency) This condition is regularly diagnosed in cattle and sheep in the Western Cape. Sporadic outbreaks regularly occur where only a few animals are affected, but it may also cause great losses. In 1 outbreak out 9 out of 150 sheep developed symptoms of opisthotonos and incoordination. Treatment with thiamine (vitamin B1) was successful. Postmortem examination revealed severe cerebrocortical necrosis. These sheep grazed on lush grass / clover pastures.

DISEASES OF OTHER ANIMALS Otter A state veterinarian from Vredendal has, on request, placed a radio transmitter in the abdomen of an otter as part of a research project of the University of Stellenbosch. Marmoset A monkey died in the Malmesbury district as a result of a Leisseria sp. infection. Another 5 unconfirmed deaths occurred. It is suspected that 2 marmosets imported from England might have been carriers of the disease. Penguins Malaria has been diagnosed again this year at the South African National Foundation for the Conservation of Coastal Birds (SANCOB). SANCOB is situated in Milnerton, next to a vlei and there are large numbers of mosquitoes in summer. This area is endemic for malaria. Penquins which arrive in a very weakened condition, have a low resistance and are therefore more susceptible to malaria. Pox has also been diagnosed at this facility.

Koi fish A farmer in the Paarl district lost 10% of a new consignment of fish, after skin lesions had been observed within 3 days of arrival. Parasites of the Trichodena spp. complex have been diagnosed as the cause by the regional veterinary laboratory at Stellenbosch. Stress as a result of movement is a common trigger mechanism for the occurrence of parasitic skin lesions. Malachite green and formalin are effective remedies. Tortoises Thirty leopard tortoises died as a result of bacterial pneumonia as brought about by the long, wet and cold winter in the Western Cape.

APPLIED RESEARCH AND PROBLEM INVESTIGATIONS Mutation rate of foot-and-mouth-disease virus in carrier buffalo This project commenced in 1991 and was completed in October 1993. Important epidemiological information was obtained. Four buffalo in captivity were infected with the Zim 7/83 virus and placed in contact with 3 susceptible cattle. The buffalo were sampled monthly for virus isolation in order to determine the rate of mutation. The cattle developed typical foot-and-mouth-disease virus lesions after 8 months and they were subsequently replaced with 3 other susceptible cattle. These 3 cattle did not show any clinical signs and had not developed any titres by the end of the trial, but the virus isolated from these buffalo showed a 3 to 6% difference as compared to the original virus, and a 1,6% difference as compared to the virus isolated the previous year. The result therefore indicates that that the virus mutates at a considerable rate in the oesophago-pharyngeal area of infected buffalo. These mutations may increase or decrease the virulence and may influence the efficacy of the vaccine. This shows therefore that foot-and-mouth-disease viruses have to be collected in the Kruger National park on a regular basis to determine the efficacy of the vaccine.

Epidemiology of African horse sickness This project was completed during November 1993. The experiment was done by sampling 120 zebra foals. Foals lose their immunity at approximately 5 months of age. They have already been exposed to all serotypes of horse-sickness virus at the age of 12 months. The infection reached its peak during winter, when a large number of foals which had already lost their passive immunity, were available. Virus could easily be isolated from these foals. The virus was present in the spleen and the lymph nodes, 42 days after infection. The experiment was carried further this year and 2 zebra in captivity were infected with strains 1 and 4. A viraemia developed and the animals ere slaughtered as required. No virus could be isolated from the lymphoid tissue after 48 days. A further survey was conducted in young elephants in captivity. It was found that 90% of them were positive for at least 1 of the 9 virus strains. Tuberculosis: development of a reliable skin test in buffalo The experiment was continued during the year. A total of 50 buffalo were captured, an intradermal test was carried out, and they were slaughtered after 72 hours. Different antigens were used � the neck and eyelid were used as injection sites. Blood was collected to facilitate gamma interferon and ELISA tests. The results were disappointing and no constant patter could be obtained. The American 40% rough tuberculin yielded poor results, as compared with the results from the previous year. The Onderstepoort 40% rough tuberculin showed no significant reactions in infected animals. It would appear that the neck area is still the most suitable area for administering of tuberculin. The eyelid did swell after the application of the tuberculin, but it was not visible from a distance. The gamma inteferon test appears to be the most reliable serological test. Lumpy-skin disease in buffalo A total of 500 serum samples were tested for antibodies, in order to determine the role of buffalo in the epidemiology of lumpy-skin disease. They were all negative. Nine buffalo and 2 cattle were subsequently intradermally infected. The cattle developed local reactions at the injection are 7 days later. The buffalo showed no lesions and were subsequently bled for the determination of titres. Negative results were obtained. One of the cattle, however, developed typical lumpy-skin disease symptoms. It would therefore appear that buffalo play no role in the epidemiology of the disease and that they have a high resistance to infection.

Survival of foot-and-mouth-disease virus in impala carcasses The trial was repeated in succession to results obtained in the previous year. Eight impala were infected with the SAT 4/81 strain. The following were investigated: • the survival of the virus in dried meat; • distribution of the virus in muscle tissue; and • determination of changes in pH and the subsequent effect on the survival of

the virus. The virus could be isolated from biltong which had been hanging for 24 hours, and a disproportionate distribution of the virus was found in individual muscles � higher titres in the cranial than in the caudal muscles. The pH stabilised after 24 hours at approximately 5,6. A further trial was carried out with SAT-1 and SAT-2-virus in 2 impala. It was again found that, although the virus does survive in the internal organs, lymphoid tissue and muscles, a considerable difference exists in the survival rate in the different types of tissue. These trials will be repeated, but it is clear that the requirements for the transport of game meat and biltong will have to be carefully determined. Survey of redwater and anaplasmosis in the Dundee state veterinary area The most common complaint during the previous year in nearly the intire Natal region was mortalities as a result of redwater. Serum samples from 284 cattle in different age groups were taken on 6 different farms. • A 75% level of exposure is required to ensure a relatively stable disease

situation. This statement is applicable to global percentages and individual farms may differ, depending on the management systems.

• The percentage exposure is influenced by vaccination, dipping, seasonal tick populations, movement of animals and the number of animals tested.

REPRODUCTION

Necrotic balanoposthitis and vaginitis This disease has reached unprecedented proportions in the De Aar state veterinary area, especially on farms where ewes have been affected as well. Most cases have only been diagnosed during routine examination of rams. Infected rams which are bought and distributed by speculators, seem to be the main cause of outbreaks of this disease. The following information discussed under Non-controlled Diseases with regard to this disease was obtained from the Brucella ovis survey: • 5% of flocks I the 1 121 questionnaires were clinically infected • 75% of infected flocks were Dorper flocks • The most successful preventative action carried out by respondents was the

slaughter of all infected animals • Careful supervision and observations during the mating season are generally

not applied. Vibriosis (Campylobacter) and trichomoniasis There has been a decrease in the number of bulls presented for sheath washes. The presence of both diseases continues to be a cause for concern throughout the beef production areas, although the percentage of infections has decreased slightly according to the number of tests carried out.

Epididymitis The following data was also obtained from the Brucella ovis survey: • Epididymitis occurred in 42% of all sheep flocks.

• Dorper flocks once again had the highest incidence figures, namely 58,9%, as compared to the 45,5% in Merino flocks. The incidence is as follows:

− 215 Merino flocks from a total of 472 were positive and − 129 Dorper flocks from a total of 219 were positive. • A total of 44,8% of the 58,9% of positive Dorper rams were adult animals,

while 31,0% of the 45,5% of positive Merino rams were adult animals. • Commercial flocks yielded proportionally more positive cases than stud

flocks. Ram tests It was found that, in areas where the testing of rams has been accepted as a management practice, the same farmers always make use of this practice. The incidence of A. seminis and B. ovis are very low on these farms and progress Is made with the control of both these diseases. Investigations as to reproduction diseases and reproduction problems as a result of mineral deficiencies, enjoy a high priority, especially in the Natal region. A considerable number of foetuses and placentas of all species are regularly received for examination. An increased number of serum samples for the determination of leptospirosis titres has been received from most regions. AI-training The AI Section at Potchefstroom continued with the training of student animal health technicians as well as students from agricultural colleges and stock farmers. The numbers were, however, less than the previous year. Officials from Lesotho also received training.

PERMITS ISSUED FOR IMPORTS: HEAD OFFICE Meat products Red meat 2 282 Poultry 1 847 Sausage casings 640 From neighbouring countries 117 Live animals Cattle 16 Goats 8 Horses 121 Dogs/cats 1 308 Zoo 19 Game 52

Poultry 144 Birds 231 Monkeys 7 Reptiles 23 Experimental animals 4 Pathology specimens 267 Semen Cattle 1 695 Dogs 8 Horse/rabbit 7 Embryos Cattle/pig 24 Hides and skins 744 Bones and horns 42 Wool 113 Fibre/Feathers 177 Hunting trophies 317 Vaccines 1 465 Biltong 778 Eggs 3 Laboratory animals 11 In transit 2 083 Sundries 61 Total 14 614

FINANCES Budget for 1993/94 Item R Foot-and-mouth disease 312 000Brucellosis 1 771 000Tuberculosis 567 000Controlled diseases 4 512 000Laboratory services 3 394 000Kruger National Park fences 170 000Rabies 833 000Computers 927 000Training 1 039 000Maintenance services 27 000Total 13 552 000

An additional amount of R56 000 was spent on rabies vaccine for the Natal region. The budget was exceeded by a further R65 000 as a result of the increase in Telkom tariffs, as well as in the tarifs of government subsidised transport. The total trade fund, however, showed an underspending of R40 000.

LABORATORY SERVICES Laboratory tests carried out Item 1991/92 1992/93 1993/94 Serology test Bovine brucellosis Rose bengal 917 811 830 752 810 545Complement fixation 81 715 85 423 43 931Serum agglutination 35 664 32 441 22 463Milk ring 46 335 35 855 69 296Haemaglutination-inhibition 36 586 41 528 24 695Agglutination 39 989 37 703 26 169Serum gel immuno-diffusion 1 595 1 230 301Serum virus neutralisation 0 452 0ELISA 25 655 30 414 0Other 10 196 17 739 11 157 Smear examinations FA 2 286 6 175 722Blood 3 097 1 566 562Brain 563 847 132Faecal 337 152 1 003Impression 477 4 956 2 949Semen 8 151 8 324 12 826Lochia 169 309 161Culture 25 444 19 251 15 204Colostrum/milk 244 192 95Other 920 1 814 685 Bacteriology Specimens examined 88 903 136 740 93 375Cultures used 185 600 146 196 138 041Identification and typing 7 496 13 536 11 628Serotyping of cultures 649 993 1 483Antibiograms 3 162 3 926 2 229Bacterial counts (semen straws) 4 321 4 767 2 218Mycological specimens examined 505 401 883Embryonated egg inoculation 5 844 5 563 8 068 Reproduction Sheath washings 14 221 15 505 6 916Vaginal swabs 1 189 1 464 782Semen quality tests 4 415 3 924 2 048Aborted foetuses 482 407 375Placentas 156 115 131Pregnancy examinations 876 892 2 233

Pathology Sections prepared (H & E) 11 872 12 840 18 470Special staining techniques 1 202 1 624 2 703Postmortem examinations Avian 16 042 10 454 13 056Other 3 401 3 386 2 300 Toxicology Tests 2 408 1 865 2 729Identification of plants 61 47 25 Parasitology Faecal specimens Egg/oocyst counts 12 699 13 958 14 136Larval cultures and identifications 367 404 3 348Identification of internal parasites 3 704 2 467 3 169Identification of external parasites 242 391 314Skin scrapings 406 251 72 Abattoir specimens Abattoir byproducts 187 561 315Bacterial counts 682 2 328 1 535Antibiotic residues 691 340 495 Mastitis Somatic cell count 134 180 154 922 110 711Biochemical tests 554 834 4 120 35 402Dip samples tested 9 1 3Biological tests 1 262 506 1 335Haematological tests 2 277 2 428 2 975Virology specimens examined 4 535 4 540 2 136Mycoplasma specimens examined 399 248 435 Laboratory products Media prepared (ℓ) 4 630 5 040 454 370Vaccine prepared (doses) 21 421 5 527 48 410Reagents and stains prepared (ml) 928 501 859 531 2 057 329Antigens prepared (ml) 11 246 8 973 33 221

LIAISON WITH FOREIGN COUNTRIES

Visits to foreign countries Dr. P.P. Bosman, Director of Animal Health, attended the Annual General Meeting of the Office International des Epizooties (OIE) during May in Paris, France. He also visited Switzerland and Belgium to investigate the importation of pork, trout ova, sheep embryos and semen and the export of ostrich meat. Dr. P.P. Bosman, Director of Animal Health, Dr. J. Krige, Deputy Director (Controlled Diseases), Dr. P.E.L.G. Kloeck, Regional Director (Natal) and Dr. R.G. Bagnall, Deputy Director (KwaZulu) attended the meeting of the Standing Committee of SARCCUS (Southern African Regional Commission for the Conservation and Utilisation of the Soil) in Swaziland. Dr. A. Faul, Deputy Director (Import and Export Control) visited Britain, Belgium, The Netherlands, Germany, Hungary and France to exchange information with veterinary authorities on veterinary control measures in the EU countries. Dr. Faul also visited the USA to attend a meeting of the American Ostrich Society. Dr. G.K. Brückner, Deputy Director (Epidemiology) visited France on the invitation of the OIE as a member of the Animal Health Information Systems Group and also visited Ireland, to obtain information with regard to their Geographical Information System for the operation of tuberculosis and brucellosis stock disease scheme. Dr. J. Krige, Deputy Director (Controlled Diseases) and Dr. A. Faul, Deputy Director (Import and Export Control) visited Zambia to supply information on the requirements for the importation of animal products. Dr. J.A.L. de Wet, Principal State Veterinarian, attended the Third International Sheep Congress in Scotland. Dr. R.J. Bagnall, Deputy Director (KwaZulu) attended a course in Tanzania on the use of the sterile insect technique for the control of tsetse flies. Mr. M.C. Erasmus, Control animal health technician, undertook a study trip to Australia and New Zealand to investigate the utilisation and application of supporting personnel in veterinary institutions. Dr. R.G. Bengis, Principal State Veterinarian Skukuza, attended the Zimbabwe Veterinary Congress in Zimbabwe and also visited the possible conservation areas where foot-and-mouth disease-free and infected buffalo will be allowed. He also visited the OIE in Paris, France as a member of the ad hoc committee on diseases of wildlife.

Dr. R.F. Horner and Dr. A.C.E. Pienaar, Principal State Veterinarians, attended the Tenth World Veterinary Poultry Conference in Australia. Dr. R.D. Last, Senior State Veterinarian, undertook a study trip to the USA and Canada to investigate improved methods for laboratory diagnostics. Dr. A.C.E. Pienaar, Senior State Veterinarian, visited Germany, The Netherlands, France, the USA, Britain, Israel and Italy to obtain firsthand information on the control of, amongst others, poultry vaccines. Dr. V. Malan, Senior State Veterinarian, attended a course on the economic principles of the control of animal diseases in The Netherlands. Dr. M.F. Swart, Senior State Veterinarian, inspected the new quarantine facilities of Sable Ranch (Pty) Ltd in Zambia on invitation of this company. Visitors from foreign countries Dr. P. Wood (Division of Animal Health, CSIRO, Parkville, Australia), an expert on the diagnosis of tuberculosis, and a bacteriologist, Dr. G. de Lisle (Central Animal Health Laboratory of the Department of Agriculture and Fisheries in New Zealand), were invited to South Africa, to share their knowledge on tuberculosis with officials of the Directorate at an International Tuberculosis Symposium. Dr. L. Mascitelli and Dr. J. Coubajales of Veterinary Services, Argentina, visited South Africa to discuss a protocol for the export of genetic material to Argentina. Dr. Clive Jackson (project leader � poultry products at the Elizabeth MacArthur Agricultural Institute) from New South Wales, Australia and Dr. Ngak Howe Heng of the Australian Quarantine and Inspection Service in Canberra, Australia, visited South Africa to investigate several aspects of ostrich diseases and testing facilities in South Africa. An EU delegation consisting of Dr Howard Batho and Dr. Alf Füssel visited South Africa to evaluate the veterinary structures and disease control measures with the view to approve South Africa as a country from which the EU member countries could allow importation of animals and animal products. Of particular importance were the export of horses, semen and embryos, venison, poultry, ostrich, game and red meat, biltong and trophies.

LIVESTOCK CENSUS 1993/94

Region Cattle Sheep Goats Horses Donke

ys/ Mules

Pigs Dogs

Eastern Cape and Karoo 624 145 6 567 686 1 470 413 25 084 14 780 78 393 137 162 Orange Free State 1 033 323 6 225 101 457 115 35 588 9 704 49 110 112 942 Western Cape 364 804 4 114 648 321 678 30 239 7 113 185 023 208 847 Natal 1 226 022 773 309 90 816 19 319 2 162 176 535 416 860 Highveld 1 739 901 2 684 735 88 869 26 573 3 262 218 155 167 300 Transvaal 1 807 309 3 095 009 76 061 34 983 3 967 325 760 435 304 Northern and Eastern Transvaal 643 080 336 765 56 560 6 728 5 998 106 863 54 693 Total 7 438 584 23 797 253 2 561 512 178 514 46 986 1 139 839 1 533 108

LEGISLATION Amendments to the Animal Diseases Act (Act No. 35 of 1984) were promulgated in the Government Gazette of 10 December 1993. The amendments include, in summary, the following: • The expression �responsible stock inspector� is replaced with the expression

�responsible technical official�. • Bovine malignant cattarrh has been removed. • Salmonella enteritidis has been added to the list of controlled animal

diseases. • Addition of regulation 26A to the regulations which state that if an animal is

infected with a disease other than a controlled animal disease and the responsible person refrains from any action, the responsible state veterinarian may apply any veterinary treatment to the animal and claim the costs and assistance required from such responsible person.

ANIMAL HEALTH SUPPORT SERVICES

The control structure of animal health technicians was adapted during the year to make provision for a Deputy Director (Support Services) and control animal health technicians on a regional level and the establishment of the position of a Deputy Director (Support Services) a chief animal health technician on state veterinary level. There are currently 147 students registered for the National Diploma: Animal Health at the Technikon SA. The first of these students (52) will receive their diplomas this year. The Directorate has been honoured by receiving a national award for the maintenance of the standard of training of students with distance ducation.

DISTRIBUTION OF VETERINARY OFFICES AND LABORATORIES

ADDRESSES OF REGIONAL DIRECTORS, STATE VETERINARY OFFICES AND VETERINARY LABORATORIES

Director: Animal Health Director Animal Health Private Bag X138 PRETORIA 0001 Tel. (012) 319 6000 Fax (012) 329 0499

Regional Directors: Animal Health Transvaal Northern and Eastern Transvaal Regional Director Directorate of Animal Health Private Bag X369 PRETORIA 0001 Tel. (012) 328 5140 Fax (012) 328 4125

Regional Director Directorate of Animal Health Private Bag X9379 PIETERSBURG 0700 Tel. (0152) 295 9258/9 Fax (0152) 291 5409

Highveld Orange Free State Regional Director Directorate of Animal Health Private Bag X934 POTCHEFSTROOM 2520 Tel. (0148) 294 4358/9/0 Fax (0148) 294 4111

Regional Director Directorate of Animal Health P O Box 502 BLOEMFONTEIN 9300 Tel. (051) 47 0407/8/9 Fax (051) 47 5240

Natal Eastern Cape Regional Director Directorate of Animal Health Private Bag X2 CASCADES 3202 Tel. (0331) 47 1931/2/3 Fax (0331) 47 1801

Regional Director Directorate of Animal Health Private Bag X12999 CENTRAHIL 6006 Tel. (041) 52 4190/91/92/30 Fax (041) 55 5113

Western Cape Regional Director Directorate of Animal Health Private Bag X5028 STELLENBOSCH 7599 Tel. (021) 887 0144/96 Fax (021) 883 8437

State veterinarians Transvaal State Veterinarian Private Bag X369 PRETORIA 0001 Tel. (012) 328 5140 Fax (012) 328 4125

State Veterinarian Private Bag X9025 ERMELO 2350 Tel. (01341) 5812 Fax (01341) 9 1223

State Veterinarian Private Bag X17 JOHANNESBURG 2000 Tel. (011) 838 5603/4/5 Fax (011) 838 4630

State Veterinarian Private Bag X4 PIET RETIEF 2380 Tel. (01343) 2103

State Veterinarian Private Bag X82087 RUSTENBURG 0300 Tel. (0142) 2 9281 Fax (0142) 2 0521

State Veterinarian P O Box 68 STANDERTON 2430 Tel. (01331) 2 1384/5

Northern and Eastern Transvaal State Veterinarian Private Bag X9379 PIETERSBURG 0700 Tel. (0152) 295 6888/93 Fax (0152) 295 6893

State Veterinarian Private Bag X209 ELLISRAS 0555 Tel. (014) 763 2137 Fax (014) 763 2438

State Veterinarian Private Bag X2408 LOUIS TRICHARDT 0920 Tel. (01551) 4271/2 Fax (01551) 5 3654

State Veterinarian Private Bag X1098 LYDENBURG 1120 Tel. (01323) 2071 Fax (01323) 5 1301

State Veterinarian P O Box 741 NELSPRUIT 1200 Tel. (01311) 5 3247/8 Fax (01311) 5 2387

State Veterinarian Private Bag X2476 POTGIETERSRUS 0600 Tel. (0154) 2155/6 Fax (0154) 6550

State Veterinarian P O Box 12 SKUKUZA 1350 Tel. (01311) 6 5641/2 Fax (01311) 6 5155

Highveld State Veterinarian Private Bag X927 POTCHEFSTROOM 2520 Tel. (0148) 294 5378/9 Fax (0148) 293 2385

State Veterinarian Private Bag X21 BETHLEHEM 9700 Tel. (058) 303 5167/8 Fax (058) 303 7669

State Veterinarian P O Box 33 HOOPSTAD 2670 Tel. (01802) 4 1910 Fax (01802) 4 1966

State Veterinarian Private Bag X28 KROONSTAD 9500 Tel. (0562) 3 2001/2 Fax (0562) 6 1653

State Veterinarian Private Bag X12040 LICHTENBURG 2740 Tel. (01441) 2 4061/2 Fax (01441) 4 1446

Orange Free State State Veterinarian P O Box 6252 BLOEMFONTEIN 9300 Tel. (051) 31 3677 Fax (051) 31 3262

State Veterinarian P O Box 5 FAURESMITH 9978 Tel. 051772 ask 182 Fax 051772 ask 5

State Veterinarian Private Bag X6005 KIMBERLEY 8300 Tel. (0531) 2 4241/2 Fax (0531) 3 1013

State Veterinarian P O Box 31 KURUMAN 8460 Tel. (05373) 2 1030 Fax (05373) 3 0139

State Veterinarian P O Box 45 UPINGTON 8800 Tel. (054) 2 2531 Fax (054) 31 1319

State Veterinarian Private Bag X19 VRYBURG 8600 Tel. (01451) 2274/5 Fax (01451) 3609

Natal State Veterinarian Private Bag X2 CASCADES 3202 Tel. (0331) 47 1931/2/3 Fax (0331) 47 1801

State Veterinarian P O Box 920 DURBAN 4000 Tel. (031) 32 6731/2 Fax (031) 368 3376

State Veterinarian P O Box 96 DUNDEE 3000 Tel. (0341) 2 2448

State Veterinarian P O Box 19 ESTCOURT 3310 Tel. (0363) 2 3119 Fax (0363) 2 4287

State Veterinarian P O Box 191 HLUHLUWE 3960 Tel. (035) 562 0006 Fax (035) 562 0318

State Veterinarian P O Box 17 IXOPO 4630 Tel. (0336) 34 1022 Fax (0336) 34 1352

State Veterinarian P O Box 96 VRYHEID 3100 Tel. (0381) 4416

Eastern Cape and Karoo State Veterinarian Private Bag X12998 CENTRAHIL 6006 Tel. (041) 55 8907/8 Fax (041) 55 4953

State Veterinarian Private Bag X536 BEAUFORT WEST 6970 Tel. (0201) 2154/5 Fax (0201) 3980

State Veterinarian P O Box 85 DE AAR 7000 Tel. (05363) 2592/3311 Fax (05363) 2129

State Veterinarian P O Box 41 GRAHAMSTOWN 6140 Tel. (0461) 2 7112 Fax (0461) 2 5870

State Veterinarian Private Bag X532 MIDDELBURG CP 5900 Tel. (04924) 2 1536 Fax (04924) 2 2253

State Veterinarian Private Bag X9022 EAST LONDON 5200 Tel. (0431) 2 3081 Fax (0431) 43 4073

State Veterinarian Private Bag X7093 QUEENSTOWN 5320 Tel. (0451) 2030 Fax (0451) 2059

Western Cape State Veterinarian Private Bag X5055 STELLENBOSCH 7599 Tel. (021) 887 5109/6 Fax (021) 886 5968

State Veterinarian P O Box 30 CALVINIA 8190 Tel. (0273) 411 0455 Fax (0273) 41 2921

State Veterinarian P O Box 2419 BELLVILLE 7535 Tel. (021) 949 5500 Fax (021) 949 5331

State Veterinarian P O Box 247 MALMESBURY 7300 Tel. (0224) 2 1380 Fax (0224) 7 1924

State Veterinarian Private Bag X6525 GEORGE 6530 Tel. (0441) 73 5527 Fax (0441) 73 3342

State Veterinarian P O Box 167 SWELLENDAM 6740 Tel. (0291) 4 1670

State Veterinarian P O Box 411 VREDENDAL 8160 Tel. (0271) 3 3106 Fax (0271) 3 3109

Veterinary laboratories Northern and Eastern Transvaal Veterinary in Charge Regional Veterinary Laboratory Private Bag X2486 POTGIETERSRUS 0600 Tel. (0154) 3285/6/7 Fax (0154) 4231

Veterinary in Charge Regional Veterinary Laboratory Private Bag X2486 POTGIETERSRUS 0600 Tel. (0154) 3285/6/7 Fax (0154) 4231

Veterinary in Charge Regional Veterinary Laboratory P O Box 12 SKUKUZA 1350 Tel. (01311) 6 5641/2 Fax (01311) 6 5155

Veterinary in Charge Regional Veterinary Laboratory Private Bag X209 ELLISRAS 0555 Tel. (014) 763 2137 Fax (014) 763 2438

Highveld Veterinary in Charge Regional Veterinary Laboratory P O Box 625 KROONSTAD 9500 Tel. (0562) 2271/2 5241 Fax (0562) 5 1782

Veterinary in Charge Regional Veterinary Laboratory Private Bag X939 POTCHEFSTROOM 2520 Tel. (0148) 249 3232/3 Fax (0148) 293 2385

Veterinary in Charge Regional Veterinary Laboratory P O Box 6252 BLOEMFONTEIN 9300 Tel. (051) 31 3677 Fax (051) 31 3262

Veterinary in Charge Regional Veterinary Laboratory Private Bag X19 VRYBURG 8600 Tel. (01451) 2274/5 Fax (01451) 3609

Veterinarian in Charge Poultry Reference Laboratory Faculty of Veterinary Science University of Pretoria Private Bag X04 ONDERSTEPOORT 0110 Tel. (012) 529 8224 ext. 224/258 Fax (012) 55 3002

Natal Veterinarian in Charge Regional Veterinary Laboratory Private Bag X2 CASCADES 3202 Tel. (0331) 47 1931/2/3 Fax (0331) 47 1801

Veterinarian in Charge Veterinary Laboratory P O Box 96 VRYHEID 3100 Tel. (0381) 4416 Fax (0381) 80 2575

Veterinarian in Charge Veterinary Laboratory Private Bag X9064 ERMELO 2350 Tel. (01341) 4846/5847 Fax (01341) 4522

Eastern Cape and Karoo Veterinary in Charge Regional Veterinary Laboratory Private Bag X528 MIDDELBURG (CP) 5900 Tel. (04924) 2 1115 Fax (04924) 2 4210

Veterinary in Charge Veterinary Laboratory Private Bag X536 BEAUFORT WEST 6970 Tel. (0201) 2154/5 Fax (0201) 3980

Veterinary in Charge Veterinary Laboratory P O Box 41 GRAHAMSTOWN 6140 Tel. (0461) 2 7112 Fax (0461) 2 5870

Veterinary in Charge Veterinary Laboratory Private Bag X7093 QUEENSTOWN 5320 Tel. (0451) 2030 Fax (0451) 2059

Western Cape Veterinary in Charge Regional Veterinary Laboratory Private Bag X5020 STELLENBOSCH 7599 Tel. (021) 887 0324/74/75 Fax (021) 886 5341