Tuberculosis in Dogs

Tuberculosis, once easily controlled with antibiotics, is reappearing with renewed strength and resistance to antibiotics. The disease is unusual in that it passes easily between humans and their pets. Tuberculosis is uncommon in dogs, but when it occurs it can be devastating. It is difficult to diagnose in dogs, has no effective treatment and poses a potential of infecting other family members, especially children.

  1. Tuberculosis Infection in Dogs

    • Tuberculosis infection in dogs is similar to the disease in humans. Dogs are susceptible to the same strain of the tuberculosis bacteria that infects humans, and dogs and humans may pass the infection to one another. Most dogs that contract tuberculosis are one to five years old, although older dogs may also become infected. Tuberculosis is primarily a lung disease, but it may also affect the intestines.

    How Dogs Become Infected

    • Tuberculosis is highly contagious and is easily spread through the air by coughing. Dogs may also become infected with the bacterium that causes tuberculosis in cows if they drink milk from a contaminated cow. Dogs are immune to a third strain that infects poultry. Dogs most often become infected from contact with humans, and dogs can pass the infection to other family members. Children are especially vulnerable. Because dogs are susceptible to tuberculosis, use caution around pets if you or a family member are diagnosed with tuberculosis

    Signs of Tuberculosis

    • A dog infected with tuberculosis may look healthy with no obvious signs of disease. Signs of infection are general and include coughing, depression, weight loss, vomiting, diarrhea, increased thirst and urination, dehydration and jaundice.

    Diagnosis

    • Tuberculosis is difficult to diagnose in dogs. The skin test used for diagnosis in people (the Mantoux test) may be used in dogs. However, the test is inaccurate in dogs with skin conditions such as mange or late-stage tuberculosis, and the results are unreliable. Other tests may diagnose the infection. These include a complete blood count to detect elevated white blood cells, biochemical profiles to determine organ function and sputum cultures to identify the bacteria. Chest x-rays may be done for dogs with respiratory problems to detect pneumonia, but tuberculosis does not show up on x-rays. A lung biopsy can provide a definitive diagnosis; however, it is a risky procedure and must be done under anesthesia. Most cases of tuberculosis in dogs are diagnosed during an autopsy.

    Treatment

    • Tuberculosis is a bacterial infection and can be treated with long-term antibiotic therapy. Success cannot be guaranteed and the treatment is associated with toxicities and is not recommended. Because of the high potential for the dog to transmit tuberculosis to other family members, most animals with tuberculosis are euthanized.