Canine Trichinellosis
This disease is an important zoonotic parasitic disease. It is known that more than 100 kinds of animals can be infected with trichinellosis under natural conditions, including carnivores, omnivores, rodents and humans, among which there are at least 65 species of mammals, and pigs and humans are mainly domestic animals. The infection rate of Trichinella spiralis in dogs in the three northeastern provinces of my country is very high.
The pathogen of canine trichinellosis and its life history
Tchinella is a small white nematode that is thin in front and thick in back. The males are 1.4-1.6 mm long and the females are 3-4 mm long, barely visible to the naked eye. Lives on the intestinal wall of the small intestine.
The characteristic of its life history is that the same animal is both the ultimate host and the intermediate host. When humans or animals eat meat containing cysts of Trichinella spiralis larvae, the cysts are digested, and the larvae escape and penetrate into the mucous membranes of the duodenum and jejunum, where they develop into adults in about 1.5 to 3 days. After mating, The male worm dies, and the female worm burrows into the canine intestinal gland or submucosal lymphatic space to produce larvae. Some of the larvae in dogs spread to the whole body with the bloodstream. The striated muscle is the most suitable parasitic site for Trichinella spiralis larvae. The larvae that just entered the muscle fibers are straight, and then rapidly develop and increase, and gradually curl and form cysts. The cyst in the dog body is round, the size of the dog is 0.25-0.3 mm X 0.4 mm, and the eye view is white needle-like. The cyst contains cystic fluid and 1~2 curly larvae, some can reach 6~7. The cysts begin to calcify within a few months or 1 to 2 years, and the larvae of the calcified cysts can still survive for several years.
Key points for the diagnosis of canine trichinellosis
The main clinical manifestations of the disease are fever, muscle pain and edema. However, the symptoms of natural infection in dogs are difficult to find, and the diagnosis before death is difficult. If necessary, muscle biopsy can be taken, and enzyme-linked immunosorbent assay or indirect hemagglutination test can also be used. Diagnosed postmortem by finding larvae in muscle. A small piece can be taken from the left and right corners of the breast muscle (or psoas muscle, abdominal muscle), and then cut into 24 small pieces of wheat grain dogs, and checked with a thick glass slide (20~50X).
Measures for the prevention and control of canine trichinosis
Improve sanitation, eliminate rodents, and burn or bury dead bodies. It is forbidden to discard animal carcasses and internal organs at will. The corpses of Trichinella spiralis detected should be dealt with according to regulations. Raw meat fed to dogs must pass a hygienic inspection to prove that there is no Trichinella spiralis before it can be fed. Trichinellosis can be treated with prothiopyrimidine, the dosage is 25-40 mg/kg body weight · day, orally in 2-3 times, 5-7 days as a course of treatment.
