Canine ascariasis

This disease is caused by canine roundworms and lion roundworms parasitizing the human small intestine and stomach. It is widely distributed in my country and mainly harms puppies aged 1 to 3 months, affecting growth and development. Severe infection can lead to death.

Canine roundworm pathogen and its life history

Canine roundworm (Toxocara canis) is light yellowish white in color, with 3 lips on the head and a long and narrow cervical wing membrane on the side of the body. . Canine roundworms are characterized by a small stomach at the junction of the esophagus and intestines. The male worm is 50 to 110 mm long with a curved tail end; the female worm is 90 to 180 mm long with a straight tail end. The color and shape of lion roundworms (Toxocara lions) are similar to human roundworms, but they have no small stomach. Male worms are 35 to 70 mm long, and female worms are 30 to 100 mm long.
Canine roundworm eggs are excreted in the feces and develop into infective eggs under suitable conditions. After puppies under 3 months old swallow infective eggs, larvae hatch out in the intestines. The larvae burrow into the intestinal wall of the dog, travel through the lymphatic system to the mesenteric lymph nodes, then reach the liver through the blood flow, and then reach the lungs with the blood flow. The larvae pass through The alveoli, bronchioles, and bronchi are then swallowed into the stomach through the larynx, and then develop into adult worms in the small intestine. The entire process takes 4 to 5 weeks. After an older dog swallows infective eggs, the larvae travel to various tissues and organs of the body with the bloodstream and form cysts. The larvae remain active but do not develop further; after the female dog containing the cysts becomes pregnant, the larvae are activated. Migrate through the placenta to the fetal liver and cause intrafetal infection. After the fetus is born, the larvae migrate to the lungs, and then migrate to the gastrointestinal tract to develop into adult worms. Mature canine roundworms appear 23-40 days after the birth of the puppies. Newborn puppies can also become infected by sucking colostrum; after infection, the larvae develop directly into adult worms in the small intestine.
The eggs of Lion Ascaris develop into infective eggs under suitable external conditions. After being swallowed by dogs, the larvae escape in the small intestine, burrow into the intestinal wall, develop and then return to the intestinal cavity. After 3-4 develop into adults.

Symptoms of canine roundworms

(1) Clinical symptoms: gradual weight loss and pale mucous membranes. Loss of appetite, vomiting, heterophilia, digestive disorders, first diarrhea and then constipation. Epileptic spasms are occasionally seen. Puppies have distended abdomens and delayed growth. When the infection is severe, roundworms are often excreted in the vomit and feces, and the diagnosis can be confirmed.
(2) Laboratory examination: The saturated salt water flotation method or the direct smear method can be used to check the eggs in the feces for diagnosis.

Prevention and control measures for canine roundworms

(1) Regular inspection and deworming: Puppies should be inspected once a month, and adult dogs should be inspected once a quarter. If a sick dog is found, deworm it immediately. Levamisole can be taken orally at 10 mg per kilogram of body weight. Or use mebendazole, 10 mg per kilogram of body weight, twice a day for two days. Or use 5-10 mg of pyrantel per kilogram of body weight, taken orally. Or take 100 mg of Qilingling per kilogram of body weight orally.
(2) Do a good job in cleaning and sanitation: The environment, troughs, and food should be carefully cleaned and sanitation should be done, feces should be removed in a timely manner, and fermentation should be carried out.