This fact sheet was developed by students enrolled in Purdue's ANSC 442 Sheep Management course in Spring 2003, as a semester project. These fact sheets provide useful information on various topics related to sheep. View the list of fact sheets.

A Sick Sheep Is a Dead Sheep
... or maybe not

Rachel, Katie, and Kara have researched the topic of health and disease among sheep and are going to enlighten you on the topic in further detail. Be sure to pay attention to all that you're learning because there will be a fun interactive quiz at the end to test all of your new knowledge. Have fun!


It is very important to keep a careful watch on your flock of sheep for many reasons. These include catching the disease at an early stage to ensure correct diagnosis and effective treatment. Early treatment is beneficial because it will present fewer losses in your flock and is economically favorable. Recognizing certain diseases requires experience, which you will gain over time, but eliciting help from your veterinarian is advised.


- Mastitis, pneumonia, and abortive diseases are to be highlighted below and are of utmost importance to sheep producers for their flocks. These are very common and can be very economically hindering.

Abortive Diseases
Preventative Health Program
Antibiotics Top Ten
Fun Quiz!

Mastitis - major reason producers cull ewes

Causes: Any type of wound or trauma can predispose the ewe to infection. Also, improper feeding around weaning time can also increase the chances for developing this disease. If fed high nutritive feeds it will cause increased milk production and absence of the suckling lamb will cause bacteria build-up and sore udders to develop.

Symptoms: Early symptoms include denial of the lambs to nurse as well as lameness. The lameness is a result of the ewe not wanting to aggravate the sore udder. Others include: reddened udders, fever, depression, and chunky milk.

Treatment/Prevention: First of all, the lambs should be immediately removed when the ewe is diagnosed with mastitis. Secondly, what seems to be most helpful is regular milking to lessen pain and timely use of antibiotics. Intramammary medication is also helpful. Other treatments available are treating with sulfamethazine at one gram per pound of body weight, or intramuscular injection of 8-10 cc of tetracycline. Prevention strategies used administering sulfas in the water supply and adding antibiotics to the feed.


Causes: Can be purely due to bacteria or due to environmental factors and bacteria. Common environmental causes are close contact with infected sheep, buildup of pathogens, irritating gases or dust, as well as any stress factor. Microbial factors include viral and bacterial. Viral causes are Para influenza and respiratory syncytical virus, adenovirus, and reoviruses. Bacterial factors are pasturella, mycoplasma, and Chlamydia.

Symptoms: The abrupt onset of fast breathing, coughing and fairly quick death are all possible symptoms.

Treatment/Prevention: First a culture needs to be done to find the specific cause of the problem. It is beneficial to make sure the facility is clean before lambing, and using a limestone base can be helpful. Always use clean bedding afterwards. Again, adding sulfas to the water and antibiotics can be helpful. 65 milligrams of Aureomycin per ewe per day for 30 days before lambing has been helpful with some flocks. Nasal spray containing Para influenza vaccine has also helped some.

Abortive Diseases

Cause 1: Campylobacter or vibrio - 10-60% of all abortions. Taken in orally by contaminated feeds or being exposed to infected sheep.
Symptoms: The ewe is not normally sick. The fetus and placenta are aborted during the 3-4 weeks of gestation. The placenta is brown and thick. If lambs not aborted, they are weak when born and most likely will die.
Treatment/Prevention: Use a killed vaccine at breeding and mid-gestation. After the first year, use a booster at mid-gestation. 40 cents/ewe/year. If ewes have not been vaccinated and abortions are occurring at a high rate, feeding 250-400 milligrams of tetracycline per ewe daily for 30 days is effective in prevention.

Cause 2: Chlamydia or enzootic abortion - affects 2-5% of ewes.
Symptoms: Ewe is sick and usually no intake of food for 2-3 days. Placenta is retained and is brown-colored. Also, the ewe usually has a vaginal discharge. Abortion will occur during the last 4 weeks of gestation.
Treatment/Prevention: Luckily, there is now a vaccine which is killed bacterin that costs about a dollar per ewe. If outbreak occurs antibiotics can be used as a prevention measure.

Cause 3: Toxoplasmosis - caused by the protozoan parasite Toxoplasma gondi.
Symptoms: Abortion occurs during the last month of gestation, some ewes will present dead lambs at birth.
Treatment/Prevention: Clean bedding and feed to keep cat excrement at a minimum. Bovatec has been useful, administered at 35-40 mg per ewe daily in late gestation at controlling the disease successfully. Rumensin can be administered at 15-20 mg per ewe daily.

Preventative Health Program

Top 10 Lessons on Antibiotics

1) Consult vet about diagnosis. Know diseases that are prevalent at a particular production stage or season.
2) Take sheep's temperature. Normal range is 101-103 degrees Fahrenheit. If there is no temperature, you should not use an antibiotic. Fever may precede other signs.
3) Treat early.
4) Maintain drug dosage for 2-5 days.
5) Prevent problems; don't put drugs before good management.
6) Check for mgmt. shortcomings as a cause of problem before using drugs.
7) Vary antibiotics, bacteria do develop resistance.
8) Take care of drugs, refrigerate, keep out of sun, and don't freeze them. READ DIRECTIONS!
9) Recognize limitations of antibiotics, they won't solve every problem.
10) Administer antibiotics correctly.

     Fun Quiz!


Jordan, R.M., Sheep Diseases:

Grotelueschen, Dale M. D.V.M., Vaccinations in Sheep Flocks:

Radostits, O.M., K.E. Leslie, and J. Fetrow. Herd Health. Philadelphia: W.B. Saunders Company, 1994.

Ricketts, G.E., R.D. Scoggins, D.L. Thomas, L.H. Thompson, and T.R. Carr. Management Guidelines for Efficient Sheep Production. University of Illinois at Urbana-Champaign: North Central Regional Extension Publication 240, 1993.