Dog Diseases – Canine Toxoplasmosis
Canine Toxoplasmosis is a worldwide zoonotic protozoan disease, which is widespread in domestic and wild animals. The disease has been reported throughout the country.
Pathogen and life history
The pathogen of toxoplasmosis is Toxoplasma gondii, referred to as Toxoplasma gondii. The entire development process requires two hosts. Cats are the final host of Toxoplasma gondii. They undergo schizosome proliferation and gametogenesis similar to the development of coccidia in cat small intestinal epithelial cells, and finally form oocysts, which are excreted with cat feces. In the external environment, the oocyst develops into an infectious oocyst containing two sporangia after spore proliferation.
Toxoplasma gondii has a lax selection of intermediate hosts. It is known that more than 200 species of animals, including mammals, birds, fish, reptiles and humans, can serve as its intermediate hosts. Cats can also serve as intermediate hosts for Toxoplasma gondii. In the intermediate host, Toxoplasma gondii can reproduce asexually in the nucleated cells of various tissues and organs throughout the body.
Animals are infected by eating infectious oocysts in cat feces or meat, internal organs, exudates, feces and milk of intermediate hosts containing toxoplasma tachyzoites or cysts. Tachyzoites can also be infected through the skin and mucous membranes. The fetus can also be infected through the placenta.
(1) Most of the clinical symptoms are asymptomatic recessive infections. Infections in puppies and young dogs are more common and the symptoms are more severe, and adult dogs also have fatal cases. Symptoms are similar to canine distemper and canine infectious hepatitis. The main manifestations are fever, cough, anorexia, fatigue, weakness, secretions in the eyes and nose, pale mucous membranes, difficulty breathing, and even severe hemorrhagic diarrhea. A few sick dogs have severe vomiting, followed by paralysis and other neurological symptoms. Miscarriage or premature birth occurs in pregnant female dogs, and the puppies often have symptoms such as loose stools, difficulty breathing, and dyskinesia. Blood test: Red and white blood cells are reduced and neutrophils increase in dogs in the acute phase. Neutropenia and mononucleosis are rare. Chronic cases have an increase in the total number of white blood cells, mainly neutrophils and thrombocytopenia, but there is no bleeding tendency.
(2) Laboratory examinations can easily be confused with canine distemper, especially neurological canine distemper, only relying on clinical symptoms. Therefore, after comprehensive judgments such as epidemiological analysis and clinical symptoms. It is necessary to detect pathogens or confirm that the antibody titer in the serum is elevated to confirm the diagnosis.
For acute infections, sulfadiazine (SD), 70 mg per kilogram of body weight, or trimethoprim (TMP), 14 mg per kilogram of body weight, can be used orally twice a day. Use it for 3 to 4 days. Since sulfadiazine has a low solubility, it is easier to precipitate crystals in urine. When taking it orally, it should be combined with the same amount of sodium bicarbonate and drink more water. In addition, sulfa-6-methoxine (sulfamonomethoxine, bactericide, SMM, DS36) or sulfonyl dapsone (SDDS) can be used.
Do not feed raw meat, and prevent dogs from preying on rodents, and prevent cat feces from contaminating feed and drinking water.