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Video: What is bovine TB?

Learn more about what bovine tuberculosis is and how this disease can spread.

What is Bovine TB? – Transcript

The Canadian Food Inspection Agency corporate introduction plays. It shows images that represent the work of the Agency, including a petri dish, strawberries, a growing plant, a chicken and a maple leaf.

Text: CFIA - Safeguarding with Science

Text: What is Bovine Tuberculosis?

Montage of Black Angus cattle in Alberta's prairies.

Off screen speaker: Former Chief Veterinary Officer for Canada 2014-2017, Dr. Harpreet Kochhar.

Bovine tuberculosis, referred to as TB, is a chronic contagious bacterial disease of livestock, and occasionally other species of mammals, resulting from infection with Mycobacterium bovis.

On screen speaker: Former Chief Veterinary Officer for Canada 2014-2017, Dr. Harpreet Kochhar.

Infected animals with progressive disease shed the bacteria in respiratory secretions and aerosols, feces, milk, and sometimes in urine, vaginal secretions, or semen. As a result, disease may be spread in a variety of ways, most commonly through the inhalation of micro-droplets in aerosols from already infected animals and from the ingestion of contaminated food and water.

Video footage of multiple Black Angus cattles eating from a feeder.

The bacteria associated with the disease may lie dormant in an infected animal for years without causing clinical signs or progressive disease symptoms. It can reactivate during periods of stress or in older animals. When disease becomes progressive, it generally results in enlarged lesions which may be found in a variety of tissues including lymph nodes of the head and thorax, lung, spleen, and liver. In countries with eradication programs such as Canada, advanced disease is rare as most cases are detected at an early stage when infection typically consists of few or small lesions in the lungs or lymph nodes associated with the respiratory system.

Bovine TB is a zoonosis, that is, an infection that can be transmitted from affected animals to people, causing a condition similar to human TB. People are most commonly infected through the ingestion of unpasteurized dairy products derived from infected animals but also through inhalation of infectious aerosols or direct contact through breaks in the skin. Currently the risk to the general population in Canada is considered to be very low due to pasteurization of milk and livestock surveillance and testing programs.

Canada wordmark. Copyright Her Majesty the Queen in Right of Canada (Canadian Food Inspection Agency), 2017.

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