How to prevent and treat tuberculosis in pigeons? Pigeon keepers need to master these methods
This disease is a typical chronic, wasting infectious disease of pigeons and other poultry, characterized by stubborn diarrhea, anemia, emaciation, and nodules of varying sizes in the organs. The pathogen is Mycobacterium avium, which is not highly virulent to humans and animals. Natural infection is usually caused by ingestion of the excreta of diseased pigeons and contaminated feed, and infection occurs mainly through the respiratory tract, digestive tract, or injuries to the skin and mucous membranes. The incidence of the disease is closely related to the quality of feeding management and nutritional deficiencies. If pigeons that shed this bacterium appear in a flock, these diseased pigeons become the source of infection, especially those with systemic tuberculosis, intestinal tuberculosis, or pulmonary tuberculosis, which are particularly important sources of infection; if a pigeon flock is kept close to other poultry, regardless of which side develops this disease, cross-infection is possible.
1. Clinical symptoms
The incubation period of this disease is relatively long, reaching 2 to 12 months. Its prominent external symptoms are anemia and emaciation. Diseased pigeons mainly have pulmonary tuberculosis, which develops very slowly, with no obvious symptoms in the early stage; in severe cases, there is difficulty breathing, the bird appears inactive, listless, with reduced appetite, drooping wings, and progressive emaciation, especially evident in the atrophy of the pectoral muscles, with the sternum noticeably protruding or deformed, general weakness, and in extremely emaciated cases the fat disappears, the skin is dry, the feathers are ruffled, and liver jaundice appears. If the bone tissue is affected, it shows unilateral lameness, with a hopping gait when walking. Occasionally, one wing droops; if there is joint tuberculosis, the joints swell and the bird limps; if there is intestinal tuberculosis, there is diarrhea; if there is pulmonary tuberculosis, there is coughing, and in severe cases difficulty breathing; if there is skin tuberculosis, tuberculosis nodules grow on the skin (especially the skin of the head). Generally speaking, this disease has no fixed symptoms, but it does have certain characteristics: slow development, long course, progressive emaciation, and ultimately ending in death.
2. Necropsy lesions
In severely affected pigeons, the lungs are covered with tuberculosis lesions. If a pigeon dies suddenly, the abdominal cavity is often found filled with blood, the liver is swollen, brittle, and has tuberculosis lesions. The spleen is enlarged and also has tuberculosis lesions. Bone tuberculosis commonly affects the femur and tibia. Intestinal tuberculosis, mesenteric tuberculosis, and tuberculous arthritis may also be seen. Tuberculosis nodules are grayish-white or yellowish-white, of varying sizes, from pinhead-sized to pea-sized. When cut open, the tuberculosis nodule can be seen to have a fibrous tissue capsule on the outside, filled with yellowish-white caseous material inside, which usually does not calcify. In some cases, after cutting open, the center of the nodule has caseous material, with lime-like calcification around it; in others, the nodule has a red ring around it, containing many small nodules, like a pomegranate cut open revealing countless small seeds.
3. Prevention and treatment
The therapeutic value for this disease is limited. Prevention and treatment methods should focus on culling and eliminating diseased pigeons, which can be burned or deeply buried, to protect uninfected healthy pigeons. However, the pigeon house (cage) as well as related equipment, tools, transport vehicles, feed troughs, water basins, etc. must be thoroughly cleaned and disinfected. Specifically, formalin fumigation disinfection or bleaching powder solution soaking disinfection can be used. The exercise yard should have the surface soil removed, quicklime spread on it, and then a layer of clean new soil laid on top. When a pigeon flock is severely infected, whole-flock culling should be considered, and a new pigeon farm built or a healthy pigeon flock re-established.
In terms of prevention, the important thing is not to introduce sources of infection; this is the key of keys. If new pigeons must be introduced, strict isolation and observation for 60 days must be carried out, and they can only be mixed into the flock after careful examination confirms the absence of this disease. Of course, strengthening routine feeding management is also extremely important.
For some poultry of particularly high economic value or valuable breeding pigeons, anti-tuberculosis drugs can be used in combination for treatment.
(1) Rifampicin (rifampin) is a new drug for treating tuberculosis; it can be given orally or by injection, with low toxicity and good tolerability. Oral dose is 30 mg per bird per time. If used in combination with streptomycin (0.1 g injection per bird), isoniazid (30 mg per kg body weight), etc., the efficacy is even better.
(2) Isoniazid (rimifon) at 30 mg per kg body weight and ethambutol (30 mg per kg body weight) used in combination have a certain therapeutic effect on this disease.
(3) Ofloxacin (fluoroquinolone) bulk powder or injectable preparation also has a certain therapeutic effect on this disease and can be selected for use.