Diseases of farm animals; Diseases of sheep and goats (small ruminants)

What respiratory disease is a major cause of economic loss in the small ruminant industry?

Pneumonia

Pneumonia can be caused by several pathogens, including...

viruses (adenovirus or parainfluenza), bacteria (pasteurella multiocida), chlamydia, mycoplasma, or parasites (nasal bot/bot fly/arm).

Pathogens that cause Pneumonia can be carried by...

sheep who may never have any problems.

What are some precipitated factors that may cause pneumonia?

Lowered resistance and stress.

What are some environmental causes of Pneumonia?

Dust, high ammonia levels in the environment, nutritional deficiency, crowding, Drafty barn, inadequate colostrum intake, and inadequate colostral antibody intake.

What are some clinical signs of Pneumonia?

Severe depression, labored breathing, decreased appetite, nasal/ocular discharge, coughing, fever greater than or equal to 104 degrees, death, gross lung lesions from pasteurella are easy to recognize, lung tissue is firm w/pneumonia (occurs in cranial/lower lung).

What is something you should do to determine a pneumonia treatment regimen?

Should do a culture and test antibiotic sensitivity to determine a treatment regimen.

How can you mass treat for pneumonia if incidence is high?

You can mass treat in there feed/water using CTC (chlortetracycline).

What is something you should take into consideration when debating culling animals that have had pneumonia?

Animal will never perform well if lungs are permanently damaged.

What are the two things you can do to treat animals who have contracted pneumonia?

Antibiotics and Supportive Therapy.

What kind of antibiotics can be used to treat pneumonia?

Mictoil; tilmicosis, Excenel; Ceftiofur, and Nuflor/resflor; florfenicol.

What kind of supportive therapy can you use to treat pneumonia?

Hydration, NSAID (non-steroidal anti-inflammatory drugs), and a clean environment.

What are the three most common causes (reproductive diseases) of abortions in sheep and goats?

Campylobacter; Fibrosis, Toxoplasma; carried by cats, and Chlamydia; Chlamoydophila.

Abortions can be ___________ of these organisms (3 most common causes of abortions).

mixture

What is the incidence of abortion in a normal flock?

1-2%

Most of the abortions caused by the 3 most common causes are ___________

late term abortions; greater than or equal to 5% of the infection that causes abortion.

Enzootic abortion of ewes is caused by...

Chlamdophila abortus (chlamydia psittaci)

How is Chlamydophila abortus (enzootic abortion) transmitted?

Can be orally transmitted, through organisms shed in uterine discharge, and through the placenta/aborted fetus.

What term does a chlamoydophila abortus (enzootic abortion) generally occur?

During the later stages of gestation (2 and 3).

What percentage of ewes can abort if infected by chlamoydophila abortus (enzootic abortion)?

25% or more can abort.

What are some definitive signs of an chlamoydophila abortus (enzootic abortion)?

Necrotic, grey/brown cotyledons, surface of the placenta between cotyledons is leathery, few or no lesions seen in the fetus. It is also hard to isolate the pathogen and grow it in a pure culture.

Define Serology as it relates to chlamoydophila abortus (enzootic abortion).

Collection of blood samples at time of abortion and 3 weeks later (titters peak at this time).

What are some ways you can treat/control ewes affected by Chlamoydophila Abortus (Enzootic abortion).

Isolate aborting ewes from the remainder of the flock, inactivated vaccines are available but their efficiency is questionable, you can also put tetracyclines in the feed (400-500 mg/head/day) for the last 4-6 weeks of gestation.

What is toxoplasmosis caused by?

Toxoplasma gondii (protozoa)

What does toxoplasmosis cause in small ruminants?

Abortions and still births.

How do small ruminants contract toxoplasmosis?

Oocytes shed in the feces of cats, ingested by the ewe on contaminated feed and hay. The oocyte lives in the muscle tissue of mice and birds, is ingested by cat making the cat the host, the cat dedicates and the ewe eats the exposed area.

What are some clinical signs of toxoplasmosis in small ruminants?

Swollen cotyledons with scattered grey necrotic areas and mineralization present, there will be no cross lesions in the fetus. You can also use serology to confirm that it is toxoplasmosis.

What is something unique about toxoplasmosis?

Animals that contract it will become immune and will not abort again.

What is the tale tell sign of toxoplasmosis in small ruminants?

Lesions in the placenta are highly characteristic of the disease (gray/white foci with little mineralized areas).

Is there any effective treatment for toxoplasmosis?

No there is no effective treatment, remember it's a protozoa. The easiest thing to do is to control the cat population.

Campylobacteriosin is also known as...

Vibriosis, caused by campylobacter.

What are some effects of Vibriosis?

Later abortions, premature births, still births, and weak lambs.

What happens to fetuses affected by Vibriosis?

Aborted fetuses die 1-2 days before they are aborted, usually they are autolyzed.

What usually happens to ewes who are effected by Vibriosis?

Ewes develop Metritus past abortion (Secondary uterine infection).

What are some treatments for Vibriosis?

Killed vaccine is available, found in combination with chlamydia and is considered to be effective. Can also use preventative levels of tetracyclines in the feed. Serology can be used to diagnose.

What are some essential things you need to do if you are going to submit a specimen for diagnosis of abortion?

Refrigerate specimens if cannot get to lab right away. Some specimens include; Fetus, Placenta, and Vaginal Swabs (campylobacter cultures). You must also have chlamydial transport media for culture of the organism and serum for the ewes or does.

What are Clostridial diseases caused by?

Clostridium endospore, causes compromised blood flow.

Enterotoxemia type-C is a...

Clostridial disease

Enterotoxemia type-C is also known as...

Purple gut.

What is the tale tell symptom of Enterotoxemia type-C?

Hemorrhagic enteritis, (bloody scours)

Clostridium perfringens type c is...

great at producing exotoxins, gram, and bacteria. Is also very rapid and acute.

When are small ruminants generally affected by Enterotoxemia type-C?

The first few weeks of life (first month or two).

What are some predisposing causes of Enterotoxemia type-C?

Changes in feed (creep feed) or amount of milk received.

Enterotoxemia type-C symptoms include...

Sudden death, depression, abdominal pain (bleating/trembling), Convulsions, more or less bloody diarrhea.

What are some things you can do to treat Enterotoxemia type-C?

Treatment is usually unrewarding, but it can be prevented.

What are some things you can do to prevent Enterotoxemia type-C?

Can vaccinate pregnant ewes around 30 days prior to lambing (A vaccine that prevents type c and d is preferred), can vaccinate lambs at 2-3 days of age and boost at 2 weeks of age, and you can give enterotoxemia antisera under the skin at birth (only temporary).

Tetanus is caused by...

Clostridium tetani.

How does Tetanus spread?

Spores germinate in devitalized tissue, toxin is very potent, injury or surgical procedures will predispose ((includes docking and castration (especially with elastrator bands))

When do signs of Tetanus occur?

1-2 weeks after organism gains entrance to the wound.

What are some signs of Tetanus?

Stiffness of limbs, difficult eating (lock jaw), Spraddle-legged stance (saw-horse), sudden noises will cause violent contraction of muscles.

When does death occur in small ruminants infected by Tetanus?

When the respiratory muscles become paralyzed.

What are some treatments you can perform for animals with a tetanus infection?

Treatment is generally unrewarding, you can: clean the wound thoroughly, large doses of penicillin and antitoxin, tranquilizers and antispasmodics can help.

What are some things you can do to prevent your livestock from getting a tetanus infection?

Vaccinate around 30 days prior to lambing (tetanus toxoid usually includes type C and D perfringes). You can also vaccinate lambs with tetanus antitoxin when castrating and docking (If they are not adequately protected by colostrum).

C. Perfringes type D. is also known as...

Pulpy kidney disease, also known as an over eating disease.

C. Perfringes type D. affects...

lambs over one month of age, mostly seen in weaned lambs/goats.

What is C. Perfringes type D. precipitated by?

Abrupt changes in feed, especially high concentration diets, also by accidental access to more feed than usual.

How fast does C. Perfringes type D. effect the animal?

Very quickly/rapidly, usually effects the largest lamb in the group.

What exactly does C. Perfringes type D. do?

Large amounts of starch in the rumen enhance the growth of clostridia and subsequent production of toxins.

What are some of the symptoms of C. Perfringes type D?

Excitement, incoordination, convulsions. Almost all causes result in death.

How did C. Perfringes type D. earn the name of pulpy kidney disease?

Rapid postmortem degeneration of the kidneys, gave rise to the name "pulpy kidney disease".

How do you know it's C. Perfringes type D.?

Sometimes there is no gross lesions at all, type D toxin can be isolated from the small intestine (ileum).

How can you control exposure to C. Perfringes type D.?

Immunization of pregnant ewes of 30 days prior to lambing, can immunize prior to increasing the concentrates in the diet (After weaning and before feeding-out period).

What bacterium causes Foot Rot?

Fusobacterium and bacteroids.

What are some signs/symptoms of Foot Rot?

Accuse lameness, usually only one foot is affected (90% of the time is the back feet), Break in the skin between claws, swollen foot.

What is an animal most likely to contract Foot Rot from?

From the soil (soil bourne bacteria), conditions have to be right and the ground needs to be moist.

What are some things you can do to treat Foot Rot?

Tetracyclines or pen-g or foot baths of bleach, copper-sulfate, etc.

What is caseous lymphadenitis caused by?

Corynebacterium pseudotuberculosis

What does Caseous mean?

Cheese like.

Caseous lymphadenitis is...

contagious, infectious and chronic.

What does the mortality look like with Caseous lymphadenitis?

Mortality is very low, but morality and production losses are significant.

With Caseous lymphadenitis, the lymph-nodes become...

abscessed.

What does an abscess contain?

Thick greenish pus, considered to be a soil borne disease.

What happens when an abscess ruptures?

They contaminate herd mates, pens, water, and barn.

When are abscess often spread between herd mates?

When sheep are shorn, clippers rupture abscesses transfer to other sheep on the blades.

What is the treatment for caseous lymphadenitis (abscesses)?

Surgically drain and flush abscess, risk releasing organism into the environment and exposing other animals. Usually not 100% effective especially if there are internal organ involved. You can flush the area and pack it with gauze soaked in iodine.

Are there any vaccines available for caseous lymphadenitis (abscesses)?

Yes, excellent for sheep but marginally effective, do not use on goats it will cause more abscesses.

What is the best way to treat an animal with caseous lymphadenitis and control the disease in your flock?

A shot of trailermicin, cull it.

What is contagious ecthyma also known as?

"Sore mount" or Orf

What is contagious ecthyma caused by?

Pox virus

How contagious is contagious ecthyma?

Highly contagious to sheep and goats, usually introduced into the flock with new animals or animals returning from shows. Causes persistent scabs which will dry and form lesions on the effected animals, the virus can live on the scabs in pastures for many months.

The virus can survive for...

long periods of time in the environment.

How does contagious ecthyma first show up as?

First appears as tiny red nodules at junction of lips.

What can happen to ewes nursing lambs infected with contagious ecthyma?

Lambs may develop lesions on the udder, this can lead to secondary infectious mastitis.

What are the steps of contagious ecthyma.

Skin must be damaged to allow viral invasion, nodules develop into blisters, thick brown scab forms, which is released in about 3-4 days, 17-21 days after the appearance of red nodules.

Contagious ecthyma can occur around the mouth of the animal but it can also occur...

between toes or around hairline (lesions on feet).

What happens to lambs who are seriously effected by contagious ecthyma?

Seriously effected lambs may loose condition because they are unable to nurse effectively.

What can you do to prevent contagious ecthyma?

There is a live vaccine which can applied to scarify skin on inside of thigh. The vaccine can be administered at one month of age. Animals that have been infected are usually immune.

What should you do when you have an animal infected by contagious ecthyma?

Separate vaccinated animals from susceptible animals until the scabs fall off.

What are the two Retroviruses of sheep and goats?

Ovine progressive pneumonia (OPP; seen in sheep) and Caprine Arthritis; encephalitis virus (CAEV; seen in goats).

Retroviruses...

cross react serologically an are considered "slow" viruses. The disease develops gradually long after animal has been infected; usually older than 4 years.

What is Retrovirus lateral transmission?

Transmission from infected to susceptible animals (nasal and oral secretions on fomites), requires ,months to years of contact in the flock, not seen as a very common method of transmission.

What is the most common form of Retrovirus transmission?

Transmission to lambs by ingestion of infected milk.

What are the clinical signs of Ovine Progressive Pneumonia (OPP)?

Coughing, fever, leathery, Bronchial Exudate, decreased appetite, slow chronic wasting, non inflammatory mastitis (Occurs in mature animals).

What is the treatment for Ovine Progressive Pneumonia (OPP)?

There are several serologic tests available but it is best to conform with histologic diagnosis, there is no effective treatment. The best thing you can do is annual serologic testing of all sheep in the flock over one year of age and remove positive reactors from the flock. If you know a ewe is positive remove the lamb prior to suckling and raise it on milk replacer, make sure to provide colostrum from negative ewes.

Caprine Arthritis Encephalitis causes...

Arthritis in older goats and encephalitis in kids 1-6 months of age.

Symptoms of Caprine Arthritis Encephalitis include...

lameness, swollen joints in older goats. Neurologic symptoms, incoordination, lethargy, convulsions, seizures, and death in goats age 1-6 months.

How can scrapie be transmitted?

Both vertical and horizontal transmission, refer to other slides.

What is a source of scrapie infection?

Placental (Vertical transmission from mother to offspring)

Infectious from of prion seems to be found in...

certain breeds and lines of animals, suggesting a genetic predisposition in black faced breeds.

What are some symptoms of scrapie?

Insidious oncset, intense pruritus (itching), loss of wool on the side of the flanks, tremble "nibbling" reflex, incoordination/ataxia, recumbency, and death.