Diseases and Parasites of

Cattle

Vital Signs of Beef Cattle

• Temp. 100.4-102.8 avg. 101.5• Pulse 60-70 BPM• Respiration 10-30 breaths per minute

Anthrax

• Caused by bacteria that may remain in the soil for 40 years or longer– Bacteria only become active under certain

conditions.

• Infection results from grazing infected pastures.

• Bacteria enter through the mouth, nose or open wounds.

• Biting insects may spread the disease from one animal to another

The Anthrax Cycle

Symptoms

• Sudden death-usually within a few hours of symptoms

• Less acute symptoms– High fever– Sudden staggering– Hard breathing– Trembling– Collapse

What to Do

• Carcasses should be burned or buried at least 6’ deep and covered with quicklime– Take care not to bury the animal near

wells or streams.

Prevention

• Vaccination• In problem areas vaccination should

occur yearly• Where it is not common, vaccinate

on the recommendation of a vet.

Anthrax

Bovine Spongiform Encephalopathy (BSE)

• Chronic, degenerative disease• Affects the central nervous system• 1 of several brain disease called Transmissible

Spongiform Encephalopathy's (TSE’s)• Other TSE’s

– Chronic Wasting Disease in deer and elk– Feline Spongiform Encephalopathy– Transmissible Mink Encephalopathy– Creutzfeldt-Jakob Disease (CJD- ID in the 1920’s)– New variant CJD (nvCJD ID in 1995)– Gertsmann-Straussler-Scheinker Syndrome– Kuru

BSE in the United States and the World

• Rare• 3 cases in the United States• First diagnosed in Great Britain in

1986– The US has not imported any beef from

Great Britain since 1985

• USDA and the APHIS maintain constant surveillance and enforce import restrictions.

Symptoms

• Nervousness or aggression• Muscle twitching• Abnormal posture• Loss of body weight• Decrease in milk production• Difficulty in rising after lying down• Eventual death

Causes of BSE• Not fully known• Related to a prion– Prion- a microscopic protein particle that

is similar to a virus but lacks nucleic acid• May be contracted by ingesting

protein in feed that came from an animal source that was contaminated– Believed to have been caused by feeding

cattle renderings from Scrapie infected sheep

• 1997 the FDA banned using ANY mammal derived protein in cattle feed in the US

Incubation of and Testing for BSE

• Ranges from 2-8 years• Death occurs within 2 weeks to 6 months after

clinical symptoms appear• No test to determine if live cattle are infected• Only a postmortem microscopic examination of

the brain can determine if the animal had BSE– Brain tissue in infected animals has a spongy

appearance when examined under a microscope

• There is no treatment for BSE

BSE

Bovine Virus Diarrhea (BVD)

• Common throughout the United States

• May appear in mild, acute & chronic forms

• Spreads by contact

Mild BVD

• Often no symptoms• If they are present:– Fever– Coughing– Discharge from the nose– Slow gains– Rapid breathing– Mild diarrhea

• Animals that have had the mild form of the disease are immune to further infection.

Acute BVD

• Fever• Difficult breathing• Discharges from

the nose and mouth

• Possible lameness• Dehydration• Weight loss• Diarrhea after 3-7

days

• Pregnant animals may abort if contracted with in the first 2 months of pregnancy

• Fetus’s may mummify if contracted from the 90-120th day of pregnancy

• Fetus may also suffer brain damage, hairlessness and underdeveloped lungs in later stages of pregnancy

Chronic BVD

• All the same symptoms as the acute plus

– Slow gains– Rough hair coat– Lameness

Prevention

• Modified live virus vaccine• Vaccinate calves between 1 day of age and 3 weeks

before weaning• May be vaccinated upon arrival in the feedlot

– They should not be vaccinated if they were vaccinated as calves

• Pregnant cattle should not be vaccinated• Adult cattle should only be vaccinated

– After calving– At least 3 weeks before breeding

• Replacement heifers should be vaccinated between 9 & 12 months of age but not during the last 3 weeks before breeding

• No cure

Brucellosis

• Caused by microorganisms• Results in heavy economic losses • Less common due to state and

federal eradication programs—all states are now free of brucellosis in domestic cattle herds

• Dangerous to humans

Symptoms

• Abortion during the last ½ of pregnancy

• Retaining of afterbirth (placenta)• Sterility in cows and bulls• Reduced milk flow • Enlarged testicles • Weak calves (if born from infected

cows)

Brucellosis Spreads By…

• Bringing infected cattle into the herd• Fence line contact with infected

animals• Aborted fetus’s that carry the Brucella

organism being carried to other farms by dogs and other carnivorous animals

• Calves being infected by their mothers• Cattle coming in contact with feed or

water where the organism is present• Sniffing or licking an aborted fetus or

calf from a cow that has the disease

Prevention and Cure

• No cure• Prevention is accomplished by good

herd management

Blackleg

• Caused by bacteria that grow only in the absence of oxygen

• When exposed to air the bacteria form a spore and may live in the soil for many years

• Spores enter the animal through the mouth or wounds

• Young animals are more commonly affected

Symptoms

• First sign is one or more animals suddenly die

• Before death symptoms are:– Lameness– Swollen muscles– Severe depression– High fever (in early stages)– Animal may be unable to stand

Prevention

• Vaccination• Calves are vaccinated when young

(typically in the spring at branding or shortly after calving) and again at weaning (fall)

• Dead animals should be burned or buried

Treatment

• Massive doses of antibiotics• Treatment is only effective if

diagnosed early• Prevention is more effective and less

costly.

Scours

• Disease complex (group of diseases)• Most common in fall, winter and

spring• Affects young calves– calves over 2 months of age are seldom

affected

Symptoms

• Acute – Shock– Nose, ears and legs are cold– Diarrhea– Sudden death

• Chronic – Symptoms for several days– Weight loss– Death after several days if not treated

Prevention

• Sanitation– Clean barns and buckets for bucket calves

• Calf needs colostrums (first milk)• Supplement the cows diet with

Vitamin A before calving• Vaccines (most common types of

scours)– Vaccinate mothers at least 30 days prior

to calving

Treatment

• Antibiotics• Sulfa drugs

Foot Rot

• Caused by a variety of bacteria, fungi and other organisms found in feedlots

• Enter the body when the skin of the foot is broken

• Muddy, manure filled feedlots only increase the problem

Symptoms

• First noticeable sign is lameness• Other symptoms– Loss of appetite– Fever– Depression– Animals may not want to stand or move

around

• Death may eventually result

Prevention

• Sanitation and paved lots work best• Good drainage and mounds in the

feedlot also help prevent conditions that encourage the disease.

• Spreading lime and 5% blue vitriol around water tanks and feed bunks

Treatment

• Penicillin• Wide spectrum antibiotics• Sulfa drugs

Lump Jaw

• Chronic • Rarely causes death• Results in economic losses because the

affected body part is condemned at slaughter

• Affects the jaw and surrounding bony part of the head

Symptoms

• Tumors or lumps on the jaw. • Loose teeth• Spongy jaw bone resulting in

breathing problems.• Weight loss due to difficulty eating

Treatments and Prevention

• Surgical treatment may allow the animal to remain marketable but complete recovery is usually not possible.

• To prevent keep sharp objects out of the feedlot or pasture.

Pinkeye

• Carried by insects• Affects the eye of the animal• A viral form of pink eye is associated

with IBR• White faced cattle and those with pink

skin pigment around the eye are more likely to be infected

• Pinkeye occurs year round but is most common during periods of maximum sunlight.

Mild Pinkeye

• Eyeball develops a pinkish color• Cornea becomes slightly clouded

Acute Pinkeye

• Flowing of tears• Cloudiness of cornea• As the infection progresses the cloudy

condition becomes worse and ulcers may develop on the eye

• The eye may become so damaged that blindness results

• The condition may last 3-4 weeks and if not treated will spread to the whole heard

Spread By

• Insects• Direct Contact with infected animals• Dust• Tail switching

Prevention

• Control flies and insects• Vacinate

Treatment

• Isolated in a dark place• Apply Antibiotics and sulfa drugs to

the eye• A cloth patch can be used on the

affected eye

Shipping Fever (PI3 Pasteurella, Bovine Respiratory Disease)

• A disease complex that affects the respiratory tract

• Most common in young cattle at times of stress

Stresses

• Moving from range to the feedlot• Extremes of heat or cold• Exhaust fumes• Hunger• Fright• Rough handling

Symptoms• Early on----fever• Depression• Drooping ears• Discharge from the

nose• Watery eyes• Loss of appetite

• Diarrhea• Weight loss• Difficult breathing• Coughing• Pneumonia• Possibly death• If the animal recovers

it will be slow to gain

Prevention

• Vaccination after 4 mo. of age• Best time is 3-4 weeks before

weaning/shipping• Reducing stress and exposure• Good feedlot management and

careful handling of new cattle

Treatment

• Antibiotics• Sulfa drugs

• Treatment must begin as soon as symptoms are noticed

• Treatment after an animal has developed pneumonia is of little value.

Trichomoniasis

• A venereal disease caused by a protozoan, Trichomona fetus

• Infects the genital tract of the bull and is transmitted to the cow during breeding

• Clean bulls can also be infected by breeding “dirty” cows

• Can also be transmitted through infected semen, even when artificial insemination is used.

Symptoms

• Abortion in early gestation• Low fertility• Irregular heat periods• Uterine infection• Cows may have discharge from their genital tract• Bulls may not show any symptoms but still be

capable of transmitting the disease during breeding

• Identified by microscopic examination of material from an aborted fetus, the prepuital cavity of the bull or vaginal discharge from the cow

Trich Prevention

• Semen testing• Testing cows before breeding• Using only clean bulls on clean cows• Selling all open cows

Vibriosis

• Reproductive disease• Both intestinal and venereal• Leading cause of infertility and

abortion in the cattle industry

Vibrosis

• Intestinal form has little harmful effect• Venereal form is more serious• If the organism infects the uterus there

will be some abortion in the herd• Number of cows infected is usually small• Cows do not become sterile and bulls are

not affected.

Symptoms

• Infertility• Abortion• Irregular heat periods• In newly affected

herds conception rates may drop below 40%

• Calving season is longer

• More open cows in the fall

• In chronically infected herds– Conception rate is

lower than normal-about 60-70%

– Heifers or new additions will require repeat breeding or will abort

Prevention and Treatment• Vaccinate animals 30 days prior to breeding▫ Vaccination must be repeated every year

• Bulls may be treated with antibiotics but the process is difficult

• Cows may settle easier if treated with antibiotics• Skipping two heat cycles before attempting to

breed the cow usually improves the conception rate of infected cows

• Cows with the disease eventually develop immunity and will breed again

• The use of AI helps in prevention because the semen used for AI is treated with antibiotics to eliminate disease organisms.

Ringworm

• A contagious skin disease that can be spread to other animals and humans

• Symptoms– Round, scaly patches of skin that lack hair

• The affected area clears up but moves to another part of the body

• Sanitation• Isolate infected animals• Treat with iodine tincture or quaternary

ammonium compounds

Ringworm