Abortion in cattle and buffalo
Also called Pregnancy loss, repeat abortion
Some pregnancy loss is unavoidable, but a run of abortions in a herd needs investigation. Infectious causes such as brucellosis, neosporosis, BVD and leptospirosis can be found with the right samples.
Cause and spread
- Cause
- Many causes: infections (bacteria, viruses, parasites), poor nutrition, toxins and genetic problems. BVD virus is one of the most commonly found viruses in aborted calves.
- How it spreads
- Depends on the cause. Some infections spread through birth fluids and the afterbirth, some through dogs, and some through carrier animals in the herd.
- People
- Some causes, such as brucellosis and leptospirosis, can infect people. Wear gloves when handling aborted calves and afterbirth.
Signs to watch for
- Aborted calves, stillbirths or weak calves
- Retained afterbirth
- Repeat breeding and long calving intervals
- More than about 3 to 5% of cows aborting in a beef herd (or over 5% in a dairy herd) is a reason to investigate
Many diseases look alike. Only a laboratory test can tell them apart, so please see a veterinarian for any sick animal.
How it is diagnosed
Samples from the aborted calf (stomach contents, tissues) and the afterbirth, together with blood samples from the cow and herdmates, give the best chance of finding the cause. Testing several causes at once saves time.
- Usually the first testAbortion Panel (Brucellosis, Neospora, BVD) (panel)Brucellosis, Neospora and BVD tested together.
- Usually the first testBrucellosis ELISAAntibodies to Brucella in the cow's blood.
- Confirms the diseaseNeospora caninum PCRDetects Neospora in aborted tissue.
- Confirms the diseaseBovine Viral Diarrhoea (BVD) PCRDetects BVD virus.
- Supports the diagnosisLeptospirosis PCRDetects Leptospira, another cause of abortion.
- Supports the diagnosisBacterial Culture and Sensitivity (panel)Grows other bacteria from the aborted calf or afterbirth.
Prevention and control
- Keep aborted material away from other animals and dogs, and dispose of it safely
- Keep a record of every abortion and the cow involved
- Quarantine and test new animals
- Vaccinate against causes that have vaccines, as advised by your veterinarian
Where this information comes from
- Abortion in Cattle · Merck Veterinary Manual
- Brucellosis: Brucella abortus (factsheet) · Center for Food Security and Public Health, Iowa State University
- Neosporosis in Cattle · Merck Veterinary Manual
- Bovine Viral Diarrhea and Mucosal Disease Complex · Merck Veterinary Manual
General information for animal owners and veterinarians, last checked October 2026. It does not replace the advice of your veterinarian, who should decide which tests and treatment your animal needs.