TB incidence is low in cats and very low in dogs. Because bovine TB is a zoonotic disease (i.e. it can be spread from animal to human), where TB is found in pets, APHA or private vets will inform the Local Health Authority so that any risks to human contacts can be investigated. If your pet is infected with TB it may show signs of disease which include coughing, wheezing and/or weight loss. Lumps, abscesses or bite wounds which fail to heal, especially those around the head and neck, can also be caused by TB and are most frequently seen in infected cats.
There is a legal requirement to report all suspicions of TB infection in the carcases of farmed animals and pets to APHA. It is only possible to confirm the infection by laboratory testing and if there is a strong suspicion of TB, APHA will undertake a pathological examination and bacteriological culture from the animal.
If samples are sent to a non-APHA laboratory (at the owner’s expense), the laboratory must notify APHA if M. bovis is identified and the laboratory is encouraged to submit samples to APHA for full identification. Treatment of TB infected pets is not recommended because of the risk this presents of transmitting the disease to other animals and/or the pet’s owner. If TB is reported in a farm cat or dog, APHA will instigate TB testing of any cattle on the farm and other, potentially exposed cattle, on neighbouring premises. M. bovis infection in cats is predominantly seen as a cutaneous (skin) form. The sites affected are frequently the sites of bite wounds such as the limbs, face and tail head, and the lesions may take the form of raised nodules or non-healing ulcers. The most commonly affected lymph node is the submandibular node. Respiratory and alimentary (gut) forms are seen less frequently. The alimentary form may be seen when cats are fed raw milk from TB infected cows.
M. bovis infection is much rarer in dogs than cats. It may be associated with bite wounds from infected wildlife. Non-healing bite wounds and enlarged calcified (gritty) lymph nodes have been described. Granulomatous lesions have also been described in the lungs, pleura, liver, kidneys and lymph nodes.
Post-mortem images of TB in cats and dogs (images include graphic content):
- Defra guidance on TB in domestic pets
- Public Health England press release 2014: Cases of TB in domestic cats and cat-to-human transmission
- O’Halloran C, Hope JC, Dobromylskyj M, Burr P, McDonald K, Rhodes S, Roberts T, Dampney R, De la Rua-Domenech R, Robinson N, Gunn-Moore DA. An outbreak of tuberculosis due to Mycobacterium bovis infection in a pack of English Foxhounds. Transboundary and Emerging Disease 2018.