Dog Diseases – Tuberculosis
Tuberculosis is a variety of infectious diseases of domestic animals, poultry, wild animals and humans caused by Mycobacterium tuberculosis. Dogs are also more susceptible to Mycobacterium tuberculosis. There are 3 types of Mycobacterium tuberculosis, bovine, human and avian. Canine tuberculosis is mainly caused by human tuberculosis and bovine tuberculosis, and very few are caused by avian tuberculosis. Dogs can be infected through the digestive tract and respiratory tract. Sick dogs can excrete the pathogen with sputum, feces, urine, and skin lesion secretions throughout the disease period. Therefore, it is a big threat to people.
Mycobacterium tuberculosis has strong resistance to the external environment, strong resistance to dryness and dampness, but weak resistance to high temperature, it can be killed in 30 minutes at 60°C. Common disinfectants need 4 hours to kill them. 70% alcohol, 10% bleaching powder solution, sodium hypochlorite, etc. have reliable disinfection effects.
(1) Clinical characteristics TB dogs often lack obvious clinical manifestations and characteristic symptoms, but gradually lose weight. Physical weakness, fatigue, and cough (dry cough or purulent sputum). When intestinal tuberculosis occurs, repeated diarrhea occurs. Appetite is significantly reduced, and lymphatic tuberculosis is characterized by superficial lymphadenopathy. When tuberculosis of mesenteric lymph nodes is obvious, it can seriously affect digestion. Dog skin tuberculosis mostly occurs in the larynx and neck, and the appearance of the lesion is a granular tissue ulcer with irregular edges.
(2) Tuberculosis test Most dogs with tuberculosis lack obvious characteristic symptoms. The tuberculin test has certain significance for the diagnosis of sick dogs. During the test, purified tuberculin can be used to inject 0.1 ml intracutaneously into the inner thigh or upper scapula. After 48 to 72 hours, the tuberculosis dog may develop significant swelling at the injection site, and necrosis (positive reaction) often occurs in the center. You can also use 1:2 dilution of tuberculin for eye spot test. Eyes are spotted twice for each quarantine (interval 3~5 days), and 3~4 drops of tuberculin (about 0.3 ml) are instilled into the same eye each time. Observed at 3, 6, and 9 hours after eye instillation, the eyelid swelling, a large amount of mucopurulent secretion, and tearing were judged as positive.
In addition, serological tests can also be performed. After the death of the sick dog, the diseased tissue can be taken for histopathological examination.
(3) Pathological autopsy features gray-white tuberculosis nodules in the lungs, even pulmonary cavities, and in severe cases, tuberculous bronchitis and pleurisy. Tuberculosis lesions on the intestinal mucosa are ulcers with embankment edges.
First, the breeding grounds for breeding dogs and family-raising dogs should be quarantined for tuberculosis on a regular basis. Dogs with open tuberculosis should be eliminated immediately. Except for a few rare breeds, tuberculin-positive dogs should also be eliminated in time and must not be mixed with healthy dogs.
Second, dogs in need of treatment should be kept in isolation. Application of anti-tuberculosis drugs, such as isoniazid 4-8 mg/kg body weight each time, 2 to 3 times a day orally; rifampicin 10-20 mg/kg body weight each time, 2 to 3 times a day.
Third, strictly disinfect kennels and places where dogs often move. It is strictly forbidden to feed and manage dogs for tuberculosis patients.