Tuberculosis is a bacterial infection of domestic animals, mainly affecting cattle and man. It is caused by Mycobacterium bovis bacteria and is distributed world wide. The bacterium is transmitted when an infected animal excretes the organism in various discharges such as exhaled air, saliva, nasal discharges, faeces, urine and milk. The germs can survive outside the host for several weeks as long as they are not exposed to harsh climatic conditions like direct sunlight.

Housed animals become infected when they inhale the causative organism. Grazing animals are infected through ingestion of the organism through feed supplementation and water troughs while calves may be infected by drinking milk from infected cows. Human beings are very susceptible to Mycobacterium bovis and Mycobacterium tuberculosis and they become affected by consuming un-pasteurized milk. The course of the disease is always chronic and usually lasts several months during which affected animals lose condition and may eventually die.

The infection causes an abscess in the lung as the first point of entry through inhalation of the causative organism. The infection then spreads to other organs and draining lymph nodes. Where infection is due to ingestion of the germs, the initial lesions would appear in the lymph nodes in the throat or intestines. As the disease advances, lesions in the lungs would cause persistent coughs stimulated by exercise.
Lymph nodes in the head, neck and fore quarters further become enlarged. The animal develops labored breathing and discharges yellowish secretion from the nose. The animal would also develop undulating fever through out the disease. Some times, the infection of the udder occurs thereby causing hard, nodular mastitis. There would be a general loss of body condition.

Enlargement of peripheral lymph nodes are indicative of the infection but not conclusive. In tuberculous mastitis the signs often involved inflammation often found at the base of the quarter of the udder with painless swellings where as in tuberculous Metritis the signs include yellow colored pus. Accurate diagnosis of tuberculosis requires the application of tuberculin test.

Because of the zoonotic nature of the disease, a lot of efforts have been put on strict control and eradication of the disease. Control measures depend on test of all animals for the disease using the tuberculin skin test. This test requires skilled man power to execute. Where animals are confirmed with the disease, infected animals can be removed and premises cleaned and disinfected. However, this exercise requires sound infrastructure and financial support to compensate farmers whose cattle are removed for slaughter.

Advancements have been made on treatment of human tuberculosis which can be applied for treatment of cattle. However, treatment of cattle is contra indicative and as such emphasis is put on prevention and control.