Infection with Mycobacterium tuberculosis in dogs most commonly occurs through contact with which organism?

Infection with Mycobacterium tuberculosis in dogs primarily occurs through contact with humans. This is due to the fact that Mycobacterium tuberculosis is primarily a pathogen that affects humans and can be transmitted to dogs in close contact with infected individuals. Dogs can become infected when they are exposed to respiratory secretions from an infected person, such as through coughing or sneezing.

Additionally, while other animals can be carriers of mycobacterial infections, Mycobacterium tuberculosis is particularly adapted to humans, making human-to-dog transmission the most common route of infection in the canine population. In contrast, contact with cattle, chickens, or swine is less likely to result in infection with M. tuberculosis, as these animals are more often associated with other species of Mycobacterium, such as Mycobacterium bovis.