Bacterial infectionsCan affect people
Bovine tuberculosis
Also called TB
A slow, wasting bacterial disease of cattle and other animals that can also infect people. Animals may look healthy for months or years before signs appear.
Cause and spread
- Cause
- Mycobacterium bovis and closely related bacteria.
- How it spreads
- Mainly by breathing in droplets from infected animals, and through milk, dung, urine and discharges from lesions. Infection can stay hidden for years.
- People
- People can catch tuberculosis from infected animals, mainly through unpasteurised milk and close contact. Boil or pasteurise milk and take care with sick animals.
Signs to watch for
- Gradual weight loss and weakness
- Low, up-and-down fever and poor appetite
- A moist cough, worse in the morning or with exercise
- Enlarged lymph nodes
- Fast or difficult breathing
- Intermittent diarrhoea
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
The skin (tuberculin) test is the main screening test in cattle and is done by your veterinarian. Laboratory tests look for the bacteria or their genes in lesions, milk, secretions and tissue; PCR is one of these.
Prevention and control
- Test cattle and keep out animals that react
- Keep animals in open, uncrowded housing with good hygiene
- Control rodents and avoid contact with infected animals
- Drink and sell only pasteurised or boiled milk
Where this information comes from
- Bovine Tuberculosis (factsheet) · Center for Food Security and Public Health, Iowa State University
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.