Bustard Preventive Medicine Programmes for Captive Breeding … · 2019-05-24 · 4. Monitor causes...

Bustard Preventive Medicine

Programmes for Captive Breeding

and Rehabilitation Projects

Dr Tom Bailey

International Wildlife Consultants, Wales, UK.

Dubai Falcon Hospital, Dubai, UAE.

National Avian Research Center, Abu Dhabi, UAE.

Bustard Preventive Medicine Programme

Health is of paramount importance for projects

releasing captive bred birds.

Disease problems in CBRPs include:

– Pink pigeons (low resistance to viral pathogens)

– Mauritius kestrels (adenovirus)

– Whooping cranes (equine encephalitis)

– Californian condors (lead toxicosis)

– Waterfowl (TB)

Health management and disease investigations are

integral part of IUCN guidelines for Re-introduction

and Rehabilitation Projects.

See J. Avian Med & Surg 1996: 10; 268-277

Design of a Preventive Medicine Programme

Breeding flock health essential component of CBRPs

Understanding the ‘disease profile’ of a species is

necessary to design flock health recommendations

At NARC we established a disease profile for bustards

and designed a flock health programme following;

– 1. Morbidity and Mortality surveys.

– 2. Serological surveys.

– 3. Consideration of endemic diseases in poultry and wild

species that birds in CBRP come into contact with (e.g. doves).

Biomedical Research

Program

2. Establish clinical

parameters in health and

disease

1. Establish laboratory

diagnostic parameters in

health and disease

4. Monitor causes of

morbidity and mortality 5. Establish optimal

medical treatment

regimens

6. Establish

biomedical studies

on free-living

populations

Outline of the core objectives of the houbara bustard

biomedical research programme of NARC.

3. Establish

biomedical

reference

collection

Biomedical Research

Program

2. Establish clinical

parameters in health

and disease

1. Establish laboratory

diagnostic parameters in

health and disease

4. Monitor causes of

morbidity and mortality

5. Establish optimal medical

treatment regimens

6. Establish colateral

biomedical studies on free-

living populations

Microbiology Parasitology

Haematology

Serology Biochemistry

Anatomy and physiology studies

Growth and development studies

Reproductiv

e studies

Nutritional studies

3. Establish

biomedical

reference

collection

Pathological investigations Serological surveys

Post-mortem examination

Vaccination trials

Pharmacological trials

Dead birds Live birds

Anesthetics trials

Database

analysis

Microbiological screening

Documentation

One outcome of the

biomedical research

programme initiated at

NARC in 1993 was the

documentation and

publication of a

significant volume of

biomedical information

primarily on Houbara and

other bustard species.

Research compiled in a

multi-author book in

2008

Summary of Conditions of Bustards (UAE)

Category Condition

Captive

adult

Traumatic injuries, musculoskeletal diseases including

capture myopathy and handling-related injuries, fatty liver

change and parasitic conditions including trichomoniasis.

Captive-

reared

juvenile

Musculoskeletal disorders, particularly nutritional bone

disease, mechanical gastro-intestinal tract conditions and

bacterial infections.

Imported

adult

Traumatic injuries, parasitic infections, opthalmological

conditions, aspergillosis, transportation associated deaths

and infectious viral diseases (PMV-1, avian pox).

Summary of major causes of morbidity of

imported and captive adult bustards

Clinical finding Imported

adult

Captive

adult

Soft tissue related traumatic injuries 26.3% 50.7%

Musculoskeletal findings 4.9% 22.9%

Parasitic findings 24.7% 15.5%

Viral findings 20.1% 0.4%

Fungal findings 0.7% 2.2%

Opthalmological findings 15.1% 5.4%

Miscellaneous disorders 8.2% 2.9%

Avian Dis 1996: 40; 121-129

Avian Dis 1996: 40; 296-305

Serological Survey of Adult Bustards

Serological surveys play an important

role in the investigation of wildlife

diseases because they can reveal

evidence of the presence of disease

when apparent infections and clinical

cases have not been detected.

Serological survey of bustards in UAE.

– Group 1 - birds in private collections in the UAE.

– Group 2 - birds imported from Pakistan into the

UAE.

– Group 3 - free-ranging birds that were trapped for

a satellite tracking project in 1994-1995.

Vet Rec 1996: 139; 238-239

Serological results following the testing of sera

from houbara bustards against avian viruses.

Virus Group 1 Group 2 Group 3

Avian influenza 0/17 0/26 0/6

PMV-1

PMV-1

9/17

51/141

17/26

36/60

1/6

PMV-2 0/17 5/26 0/6

PMV-3 0/17 0/26 0/6

Avian pox 0/17 8/26 1/6

Infectious bronchitis 0/17 0/26 0/6

Avian Pneumovirus 0/12 0/24 0/5

Serological Survey

Major Findings

– Grp 1 - 38% +ve to PMV-1

– Grp 2 - 62% +ve to PMV-1

– Grp 2 - 31% +ve to Avian pox

– Grp 2 - 19% +ve to PMV-2

Conclusions

– importation exposes HB to viral diseases.

– do not manage HB and poultry on same

premises.

– vaccination programmes against viral

diseases necessary for CBRPs.

Seasonal pre-breeding health

monitoring

Two months before the breeding season birds:

weighed.

clinically examined.

identified with a ring or PIT.

collection of biomedical samples

– routine health screening

– storage in biomedical reference collection

– specific research projects.

treated for ectoparasites and endoparasites.

Vaccinated

– Avian pox and Newcastle disease virus.

Range of samples collected during pre-

breeding health examination

Parasitology

– OP swab in saline for direct microscopic examination

– Fecal sample for flotation and direct microscopic

examination

Microbiology

– Cloacal swab - aerobic bacteriology

Blood samples collected in pediatric tubes

– EDTA -haematology and blood parasites

– Plasma -biochemistry, vitamin or trace element

analysis

– Serum -vaccine assessment, serological surveys or

banking

Chlamydia status

– choana/cloacal swabs for ELISA antigen

Virology

– choana/cloacal swabs for virus isolation

Prophylactic medications

Trichomoniasis control.

– All adult and juvenile bustards receive anti-protozoal

medication administered in the water three times a year, in

February, June and October.

Endoparasite control.

– All adult and juvenile bustards receive anthelmintic medication

administered in the food three times a year, in February, June

and October.

In-feed medication

– Addition of anthelmintic and antiprotozoal medication used in

1992. Beware resistance.

Pox Vaccination

Cross-protection study at NWCD, KSA used pox isolated

from HB and vaccinated/unvaccinated canaries (canary

pox virus vaccine).

Study demonstrated that vaccinated canaries survived

challenge with HB pox and canary pox virus.

Studies needed to confirm this using houbara but this

trial supports the recommendation that HB should be

vaccinated with CP vaccine.

Poulvac P Canary (Duphar, Holland) used at NARC

See Avian Dis 1996: 40; 762-769

Newcastle Disease Vaccination

Trials at NARC using previously vaccinated adult HB

given a booster of 1ml/kg s/c inactivated oil emulsion

PMV-1 vaccine (Newcavac Nobilis, Intervet).

Antibody levels monitored monthly for 12 months by ND

HI.

Mean titre (n=6) log2 7 for 6 months and > log2 4.5 for

the remaining 6 months.

Work in chickens has shown that field challenge with

PMV-1 will not kill chickens with antibody titres > log2 5.

Annual vaccination of previously vaccinated adults

should provide protection against PMV-1.

Mean PMV-1 HI inhibition titer in adult

bustards given inactivated vaccine

0

2

4

6

8

0 4 8 12

16

20

24

28

32

44

48

52

56

Time after vaccination (weeks)

HI ti

tre

2^y

See J. Zoo & Wildl Med 1998: 29; 441-450

Other vaccinations

Avian influenza

– H9N2 (Gallimune 208 ND

+ Flu H9)

– H5N2 (Nobilis Influenza

H5, Intervet)

Reovirus

– Heuglin’s bustards

(Dubai, P McKinney) –

Nobilis Reo (Intervet)

Pre-catch medications for adult bustards

Water soluble multivitamin products routinely

administered to the water of aviaries (and/or food) of

bustards for periods of up to one week before a known

catch or translocation is planned.

Done to reduce the incidence of capture-related causes

of morbidity and mortality such as paresia or stress-

related deaths.

Important for the more nervous birds in the collection

that are not used to being handled.

Bustard Pediatric Diseases

Chick health can limit success of CBRPs

Conditions of chicks different to adult diseases

Understanding of ‘disease profile’ necessary for the

creation of health recommendations for captive bred

birds

Review of pediatric diseases at NARC (1993-1995)

during first 180 days of life

Survey of 137 chicks

Species - HB, RCB, KB

J. Av Med & Surg 1997: 11: 166-174

Mortality of bustard chicks over first 180

days after hatching

27

11

76

12

0

5

10

15

20

25

30

<30 31-60 61-90 91-120 121-150 151-180

Age (days)

Mo

rtality

Morbidity of bustard chicks during first 180

days after hatching

118

3240

2024 27

0

20

40

60

80

100

120

140

<30 31-60 61-90 91-120 121-150 151-180

Age (days)

Mo

rbid

ity

Bustard Pediatric Survey

Results

45% morbidity occurred during 1st 30 days.

52% mortality occurred during 1st 30 days.

Major juvenile health problems

Bacterial diseases.

Mechanical abnormalities of GIT.

Musculoskeletal problems.

Parasitic problems.

Mechanical abnormalities of GIT

Important cause of death (16%) and morbidity

(4%) over the 180 day period.

RCB susceptible to gizzard impactions cf other

species .

Foreign body impactions of proventriculus or

ventriculus.

– Septicemia sequela to impaction.

– Surgical removal often possible.

‘Overload ventriculus’ reported in other bustards,

recommended to feed some small grit until chicks

learn to pick grit themselves.

– Impaction with grit reported in HB at NWRC, KSA.

Care with environmental contamination.

‘Hardware’ disease in bustards

Clinical signs

– decreased appetite, depression, palpable abscesses,

intermittent feces with partially digested ingesta, weight loss

Diagnosis

– radiography - confirmation of foreign body in ventriculus

– haematology heterophilia in acute cases, monocytosis in

chronic cases

Surgical treatment

– ventriculotomy via saccus caudalis following lateral or midline

celiotomy

– supportive medical treatment (fluids, antibiotics, diet)

Above (right). Juvenile RCB, lateral projection. Massive enlargement of the ventriculus (black

arrows) and enlarged renal shadow (white arrows). This bird was under treatment of gastric

stasis and died shortly after hospitalisation. The cause of death was peritonitis and

generalised bacteraemia secondary to impaction of the ventriculus.

Anatomical features

Ventriculotomy described in cranes

– BUT as a muscular organ the poor holding strength of sutured

muscle combined with the rhythmic ventricular contractions make

dehiscence of the suture line a possible complication

BUT - in bustards the tenuis craniodorsalis and tenuis

caudoventralis muscles are comparatively thin and are

present in the saccus cranialis and saccus caudalis which

make up the tapering ends of the ventriculus

Surgical access to ventriculus in bustards possible

through the saccus caudalis

Left lateral celiotomy

Skin incision posterior and parallel to the last rib

Separate abdominal muscles, expose and cut

peritoneum to enter abdominal cavity

Exteriorize ventriculus with stay sutures

Incision through the saccus caudalis at the caudal end

of the ventriculus

Remove FB

2 layer closure of ventriculus with polyglactin 910

– 1) the mucosa and submucosa closed with continuous sutures

– 2) muscle wall closed with Cushing’s sutures

Ventral laparotomy

saccus caudalis

in bustards is

accessible by a

ventral

laparotomy

Ventral midline approach to the abdominal cavity

of a kori PM demonstrating the accessibility of the

saccus caudalis of the caudal ventriculus by this

approach.

Bacterial Diseases

Bacterial diseases - important cause of death over 1st 30

days (62%) and in total over 180 days (40%).

Factors predisposing chicks to infection

– stress, poor nutrition, environmental contamination, immaturity of

the immune system.

Conditions

– septicemia, sinusitis, meningitis, YSI, rhinitis, stomaitis,

conjunctivitis.

82% bacterial isolates G-ve.

– Pseudomonas aerugenosa, E.coli, Salmonella spp., Yersinia

pseudotuberculosis.

– Staphylococcus spp most common G+ve.

Chicks are coprophagic - isolate sick birds.

Depressed white-bellied bustard

chick with Escherichia coli

septicaemia and enteritis, notice the

closed eyes and ‘sleepy’ appearance Houbara bustard chick with

omphalitis caused by E. coli

Buff-crested bustard chick showing enteritis and CNS

signs including ataxia, loss of balance and

incoordination. Salmonella sp. was isolated from

clinical samples and the bird responded to antibiotic

therapy

Musculoskeletal Disorders

Bustards are long-legged birds and MS abnormalities

are and important factor in their health and

development.

Musculoskeletal conditions - important cause of

morbidity over 1st 30 days (50%) and over 180 days

(49%).

In bustards 46% of MS findings occurred during 1st 30

days. In HB most findings during 31-60 days.

See J. Av Med & Surg 1998: 12: 82-90


Angel Wing

Lateral rotation of the distal wing

Most common MS finding - 18%

chicks at 5-19 days

More common in WB (83%) & KB

(26%) cf RCB (10%) & HB (6%)

Causes - weight of blood-filled

primary feathers causing wing tips to

twist outwards, incubation

interruption, XS heat during growing

period, high protein, genetics, Mn

deficiency

Correct by taping wing in normal

position for 3-5 days

Kori bustard with wings taped to

correct angel wing


Rolled Toe

Medial rotation of the

phalanges.

Common MS finding (12.6%

chicks).

Causes - riboflavin deficiency,

embryo malposition, genetics,

incubation problems,

unsuitable substrates,

inherited in chickens.

Correct early by prompt

taping or splinting.

Curly toe in a kori bustard chick


Spraddle/Splayed leg

More common in RCB (23%), but occasionally seen in

HB.

Occurs from 0-48 hours after hatching until 8 days.

Causes - incubation, floor of hatching box, prolonged

hatching, high incubation, poor egg quality, lack of

exercise, high protein diet.

Correct by hobbling chicks with 3M Vetwrap at level of

mid-metatarsus and keep in small padded container.

Provide newly hatched chicks with rough surface.

White-bellied bustard with

hobbles to correct splayed legs

White-bellied bustard with

splayed legs


Angular and rotational limb deformities

ALD and RLD can occur until 120 days post hatching.

Common in chicks (19% total findings), highest

incidence in KB.

Varus deformity common.

Most abnormalities in distal tibiotarsus and proximal

tarsometatarsus where most longitudinal growth

occurs, but deviation of radius and ulna seen in KB.

Causes - multifactorial, genetics, incubation, decreased

exercise, high fat/protein diet, poor substrates, rapid

growth rate, nutritional imbalances.

Marked distortion of the right

leg of a kori bustard due to a

rotation of the tibiotarsus

Bilateral distortion of legs of a WB

bustard due to bilateral rotation of

the tibiotarsus bones

Houbara bustard chick with

shortened metatarsi

Houbara bustard chick with fused

tarsometatarsal trochlea of digits

I and II

Legs of a 50-day-old houbara bustard with a) soft

tissue swelling above the intertarsal joint, b) short

tarsometatarsus, c) varus deformity of the distal

tarsometatarsus, and d) fused tarsometatarsal

trochlea of digits I and II. The ossification of the

proximal tarsometatarsus is in progress (arrow).


Fractures

Common (25% of MS findings).

Timing differs between species; RCB - 61-120 days;

HB 31-120 days; KB 31-180 days.

Ulna and radius most common site.

53% found incidentally during routine radiography

which could indicate that nutrition is imbalanced.

Pinioned wings more prone to fracture d/t lack of

protection by primary feathers.

Ca and Vit D3 deficiencies implicated in folding

fractures in juvenile HB at KSA.

Dropped wing in a white-bellied

bustard with a fractured ulna.

Metabolic bone disease

White-bellied bustard. Multiple

fractures of both humeri and ulna.

Metabolic bone disease


Conclusions

Aggressive care of bustard chicks during first 30 days

after hatching is important.

Implementing the recommendations described reduced

chick mortality from 71% to 25% between 1993-95 at

NARC.

Pediatric dietary management and monitoring of chick

growth rate is essential to minimise MS problems.

Consider environmental monitoring of incubation and

rearing facilities.

Health Recommendations for Juvenile

Bustards

The following procedures are carried out to maximise the

health of captive-bred, hand-reared bustard chicks;

Application of 1% iodine solution to the umbilici of

chicks promptly after hatching.

Administration of antibiotics and s.c. or p.o. electrolytes

for 24-48 hours to chicks that have had a delayed or

assisted hatch.

Supplementation of the rearing diet with a vitamin D3

and calcium (Neutrobal, Vetark, UK) from 2-90 days.

This product is lightly dusted onto the live food items.


Bustards

Supplement rearing diet with calcium between days 30-

60 at a dose rate of 300 mg elemental calcium per chick

twice a week.

Supplement rearing diet with probiotics from 0-14 days,

one week before and after translocations between

aviaries, and if birds are given antibiotics.

Ensure rearing environment is not contaminated by

material that could become ingested and cause foreign

body obstruction or perforation of GIT.


Bustards

Administer appropriate antibiotics to treat bacterial

conditions

– Gram-negative bacteria most frequent isolates from clinical and

post-mortem cases.

Vaccinate chicks against avian pox and Newcastle

disease using commercial poultry or pigeon vaccines.

– Chicks as young as 14 days can be vaccinated, but fewer side-

effects were seen when chicks >30 days are vaccinated.

Administer anti-protozoal medication to chicks that are

been translocated to naturalistic aviaries.

Vaccination protocols for juvenile bustards

Captive-bred bustard chicks are vaccinated against;

Newcastle disease.

– Vomiting and diarrhoea have been observed in chicks two

weeks of age following intra-ocular live Newcastle disease

vaccine.

– Chicks given live Hitchner B1 Newcastle disease vaccine at one

month of age and side-effects have rarely been seen.

Avian pox.

– Chicks as young as two weeks of age have been vaccinated

with half a dose of commercial poultry pox or canary pox

vaccine via the wing web route and no side-effects have been

observed.

Mean HI titres of bustards given live IO B1 ND vaccine (wk 0),

live IO La Sota ND vaccine (wk 4) and inactivated vaccine (wk

12) at 1.0 ml/kg

-1

1

3

5

7

9

0 4 8 12 13 14 15 16 20 26 30 34 38

Time after vaccination (weeks)

HI ti

tre

2^y


Mean ND HI titres of bustards given IO B1 ND vaccine (wk

0), three IO La Sota vaccines (wks 4, 10, 16) and

inactivated vaccine (wk 24) at 1.0 ml/kg SC

0

1

2

3

4

5

6

7

8

0 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 24 28 32 36 40 44 48 52

Time after first vaccination (weeks)

HI T

itre

2^y


Vaccination protocols for juvenile bustards

Juvenile bustards should receive a second dose of

inactivated PMV-1 vaccine 4-6 months after their first

dose of inactivated vaccine.

Objective of a (PMV-1) vaccination programme is to

minimise the susceptible period between waning

passive immunity and the establishment of active

immunity.

Vaccination of poultry derived from immune flocks is

hindered by maternally derived immunity (MDI).

PMV-1 HI antibody levels (log2 ) in KB dams and in

yolk, albumen or a yolk-albumen mixture (mix)

derived from infertile eggs.

PMV-1 HI Titer (log2 )

Dam ID (Egg

ID)

Dam pre-

breeding

season

Dam

post-

breeding

season

Yolk

Albumen

Mix

429 (96/18) 1 0 0 0 Nd

623 (96/26) 4 8 nd a nd 5

623 (97/01) 4 8 5 3 Nd

632 (96/09) 4 8 Nd nd 4

618 (97/02) 5 8 8 5 Nd

See J. Wildl Dis 1998: 29; 441-450

PMV-1 HI antibody levels (log2 ) in KB dams before

and after the breeding season and in their chicks.

PMV-1 HI Titer (log2 )

Dam

ID

Dam pre-

breeding

season

Dam

post-

breeding

season

Chick 1 Chick 2 Chick 3

429 1 0 0 nda nd

628 3 8 7 5 8

623 4 8 5 5 nd

632 4 8 4 5 8

637 5 8 8 nd nd

638 5 8 8 nd nd

See J. Wildl Dis 1998: 29; 441-450

Maternally derived immunity in bustards

In a study of previously vaccinated KBs at NARC it was

shown that maternal antibodies are transferred from

dams to their chicks.

PMV-1 antibodies are transferred to eggs and chicks

from KB hens previously given inactivated vaccine.

Chicks hatched from dams with high antibody titers had

high MDI levels.

Mean antibody levels in chicks was log2 6.3 on day 14

and log2 2.9 at day 42.

Antibody half-life in 14-21 day chicks was 5.5-6.3 days,

which is similar to chickens.

Decline of maternally derived PMV-1 HI

antibodies in kori bustard chicks.

0

1

2

3

4

5

6

7

8

0 7 14 21 28 35 42 49 56 63 70Age (days)

HI ti

tre

2^y

See J. Wildl Dis 1998: 29; 441-450

Maternally derived immunity in bustards

Antibody half-life in 28-42 day chicks was 12.3 days

– slower cf chickens (but similar to parrots).

Species differences in decline of MDI and hence in

timing vaccination regimens.

MDI levels of >log2 4 protects poultry chicks against

PMV-1 challenge.

Our data suggests that unvaccinated bustard chicks

could be protected against PMV-1 challenge for up to 4

wks.

High risk of PMV-1 infection - vaccinate at 3-4 wks

Low risk of PMV-1 infection - vaccinate at 6-8 wks

See J. Wildl Dis 1998: 29; 441-450

Other Measures

Other non-medical measures can be considered to

improve health of captive bustards.

Adult and juvenile bustards are “trauma susceptible”.

Minimise trauma by;

– 1. Modifying behaviour by taming nervous individuals or

housing such birds in naturalistic pens with cover.

– 2. Enclosure design using padding or shade-cloth to reduce

potential danger zones.

– 3. Pinioning and feather cutting.

– 4. Consider genetics (migratory behaviour in captive setting).

– 5. Chemical modification of behaviour (future).

Environmental monitoring

Environmental monitoring provides feedback on

efficacy of disinfection and hygiene protocols

Sources

– food samples

– food preparation areas

– artificial incubation,natural/surrogate incubation facilities

– hatching and rearing facilities

– water sources

Sampling

– aerobic bacteriology and fungal culture from settle plates and

direct swabs from environment

– aflotoxins in food samples

Quarantine

Essential to minimise

risk of infectious

disease being

introduced into CBRPs.

Quarantine should

facilitate screening of

birds entering or

leaving CBRPs.

Quarantine

Quarantine considerations

1. Locate safe distance from CBRP center and

neighbouring agricultural areas.

2. Protect from predators.

3. Multiple wards to enable multiple groups of

birds to be separately accommodated.

4. Central unit for clinical activities.

5. Buffer zone between wards and clinical area.

Quarantine

6. Facilities for personnel hygiene.

7. Facilities to disinfect car tyres/rubber boots.

8. Maintain required temperature and

humidity.

9. Observation of birds without causing

disturbance.

10. Ability to separate birds from a group to

allow catching (sliding doors between pens).

11. Incineration capability.

Int Zoo Yb 1997: 35; 256-261

Quarantine protocols

Incoming birds quarantined for 45 days

Health screened for:

1. Virus isolation (cloacal/choanal).

2. Serology (PMV-1, Chlamydia).

3. Chlamydia ELISA antigen (choana).

4. Parasitology (OP swab, fecal).

5. Haematology.

6. Microbiology (cloacal).

Optional - endoscopy, blood chemistry.

End Piece

Health and disease are dynamic processes.

New diseases emerge

– e.g. Chlamydia, Reovirus, Adenovirus, Avian Influenza

Old diseases decline due to improvements in husbandry

– e.g. Trichomoniasis important in naturalistic aviaries, but rarely

seen in environmental-control units

Health monitoring should be on-going.

Preventive medicine programmes need to be flexible.

Good science is needed to investigate health problems

and to find optimal solutions.

Thanks to colleagues at :

– NARC

– DFH

– IWC

– ZSL

– GBT

– HFI

– Who have shared information

with me over the years

Thanks

Bustard Preventive Medicine Programmes for Captive Breeding … · 2019-05-24 · 4. Monitor causes...

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