ENZOOTIC ABORTION OF EWES (EAE)
WHAT CAUSES ENZOOTIC ABORTION?
Chlamydia psittaci causes EAE. This organism is classified as a rickettsia, which is smaller than a bacteria and larger than a virus. This organism generally produces abortions, conjunctivitis (eye infections), arthritis in lambs, epididymitis (resulting in reduced fertility or sterility in males), pneumonia, and diarrhea.
HOW IS THE DISEASE TRANSMITTED?
The disease is normally introduced into a flock by the purchase of an infected ewe. The vaginal discharge and after-births of infected sheep are highly infective and will contaminate the pastures. The organism can also be shed via feces. Ewe to ewe infection usually occurs during lambing time.
There are no apparent clinical signs in ewes in infected ewes. Abortions normally occur during the last month of pregnancy. The farmer's biggest concern will be a low lambing and weaning percentage. Apart from abortions, affected ewes give birth to weak and unthrifty lambs, most of which will die within a few days.
WHEN TO VACCINATE?
Ewes should be vaccinated at least 4 weeks before mating. Ewe lambs intended for breeding can be vaccinated from 5 months of age. Do not vaccinate pregnant animals or animals which are being treated with antibiotics, particularly tetracyclines.
Below is a List of Related Websites on the Subject
Abortion in ewes has many causes. Some are infectious like enzootic abortion of ewes (EAE)/chlamydiosis (Chlamydia psittaci), vibriosis/campylobacteriosis (Campylobactre fetus), brucellosis (Brucella spp.), toxoplasmosis (Toxoplasma gondii), listeriosis (Listeria monocytogenes), and salmonellosis (Salmonella spp.).
1. Prevent contamination of feed and water by not feeding on the ground or watering from stagnant contaminated pools.
2. Prevent contamination of feed and water with feces from rodents, birds and cats.
3. Immediately isolate all aborting ewes or those with vaginal discharges from the main flock.
4. Properly dispose of infected fetuses, placentas, litter and dead lambs.
5. Develop a sound, cost effective vaccination program against infectious agents of major risk in your operation.
This disease is caused by Campylobacter fetus spp. fetus (In general, this infection in sheep and goats is NOT caused by the same organism that causes abortions in cattle, and the vaccine for cattle is NOT effective.) The name of this bacteria has been changed from Vibrio fetus intestinalis to Campylobacter fetus spp. fetus. This disease causes abortions and dead or weak newborns. It is probably the most common cause of abortions in sheep.
WHEN TO VACCINATE?
A vibriosis vaccine is available that will effectively prevent the disease in most flocks. Ewes should be vaccinated twice the first year in early gestation and again in mid gestation and once yearly there after,usually immediately after the breeding season. Abortion episodes attributed to vibriosis can usually be stopped by immediate vaccination and flock treatment with 5 mg/lb. body weight of oxytetracy-cline or chlortetracycline in the feed for 5 to 7 days
PRACTIONERS APPROACH TO OVINE ABORTION
This page was last updated on: March 10, 2008