Toxocariasis Is A Dangerous Invasion For Dogs, Cats And People

I want to start talking about parasites of domestic animals with toxocariasis, as this invasion is of great importance for our city. These parasites infect not only cats and dogs, but also people, and the infection of people is constantly growing. Cats and dogs are parasitized by specific, that is, characteristic only of them, toxocars. The canine species, Toxocara canis, also parasitizes some wild animals related to dogs, as well as mice and rats. Feline toxocars - Toxocara cati (T. mystax) - can also infect other felines and also use rodents as additional hosts. This species is less pathogenic than canine. Toxocaras have a very complex life cycle, which ensures that they use all the mechanisms of penetration into the host's body. For adult dogs and cats and for kittens and puppies these mechanisms are different,primary infection of adult animals, and it causes the transmission of infection to offspring. Let's start to understand these processes from the very beginning, that is, from the egg. Toxocar eggs are excreted in the faeces of animals affected by them. So, the infected dog pooped in the street and cheerfully went for a walk. The faeces dry out in the air and become, together with the eggs they contain, a component of street dust. To infect the next hosts, the parasite larva must develop in the egg. This process takes from 5 days to several weeks, depending on the air temperature and humidity. The climate of our region, unfortunately, is quite favorable for the development of the eggs of these parasites. In winter, Toxocar eggs do not freeze, their development is simply inhibited until the onset of a warmer time. Infection of dogs and cats with toxocars occurs in several ways. The first way is direct infection, when they swallow their eggs with street dirt. Owners of perfectly educated dogs, do not rush to rejoice! Even if your dog knows for sure that nothing can be taken in the mouth on the street, the air-dust method of infection is not closed for it. Together with street dust, toxocar eggs rise into the air by the wind, finally, just with the active movement of the dog. We bring toxocar eggs home on shoes from the street, here they become part of house dust, get on the animal's fur and then when licked inside. In the intestine, the larva of the parasite emerges from the egg. The second route of infection is with the use of additional hosts, in the body of which toxocara larvae do not develop, but accumulate in the internal organs. For Toxocara, such hosts are rodents and even earthworms. When they are eaten, mostly stray animals become infected. Some domestic animals (sheep, cows) can also serve as such storage hosts. Their larvae are concentrated mainly in the liver, but in principle they can be found in any other organs. If cats or dogs are fed such raw meat, infection can also occur. The further path of toxocara larvae that enter the body of a dog or cat by the first or second method is fundamentally similar. The larvae actively penetrate the intestinal wall and enter the blood vessels. With the blood flow, they reach the lungs, where part of the larvae breaks the alveoli and penetrates the lumen of the bronchi and trachea. From there, either actively crawling, or when the animal coughs up, they fall into the mouth and are then swallowed along with saliva. In this way, the toxocar larvae again enter the intestines and here they finally develop into adult worms. Another part of the larvae does not leave the bloodstream in the lungs, but continues its journey through the body with blood, gradually settling in various internal organs. These larvae do not turn into intestinal, but into tissue parasites. They can affect any internal organs, but their favorite habitats are the lungs, liver, lymph nodes, spleen and brain. Toxocara larvae do not grow in the internal organs; this is a strategic reserve for infection of the next generation. The larvae live in the host's body for up to 10 years. Some of the larvae die over time under the influence of the immune system. However, a significant part of the larvae remains viable. Foci of inflammation are formed around them, and the surrounding tissues are destroyed. Moreover,periodically, the larvae are activated, again penetrate the bloodstream, and again begin to migrate through the body, affecting new parts of the animal's body. Pregnancy is a special stimulus for migration for toxocar larvae: when the hormonal background of the animal changes, the larvae amicably leave their "homes" and with the blood flow reach the placenta, which they actively overcome, then enter the bloodstream of the developing fetus and affect its tissues. But their journey doesn't end there! Soon after the birth of puppies or kittens, the larvae again enter their bloodstream and pass the path already described above through the lungs into the intestines, where they quickly develop into sexually mature worms. But this does not exhaust the possibilities of infection with toxocariasis! Part of the larvae remaining in the internal organs of the mother, after the birth of the young, again enters the bloodstream,passes into the mammary glands and passes into milk. If the mother becomes infected with toxocariasis during feeding, the larvae also end up in the milk. These larvae infect puppies or kittens by sucking. After 3 weeks, multiplying worms appear in the intestines. Thus, toxocaras use all possible routes of host infection. Such a perfect transmission mechanism leads to the fact that the infection of animals is very high. There is no reliable statistics for Russia, but the infection rate of dogs in some Western European countries reaches 93%. There is a pattern: the larger the city, the more dogs there are, the higher the infection. Cats are slightly less infected - up to 25%. The explanation for this is simple - not all cats regularly walk outside. However, even for absolutely domestic cats there is a risk of infection through the street dirt brought on the shoes. Symptoms of toxocariasis in adult animals are not always noticeable. Dogs and cats become less active, they may develop appetite perversion - they eat polyethylene, feces from other animals. Digestion is periodically upset. The size of the lymph nodes increases. Poisoning of the body with worm toxins affects their nervous system, animals can show unmotivated aggression. Sometimes, with severe infection, seizures are observed. The animal develops anemia, a violation of hematopoiesis, a decrease in immunity. Eosinophilia is characteristic. Toxocariasis causes a violation of protein and mineral metabolism in animals. The owners may notice the pale coloration of the mucous membranes in the mouth. The condition of the coat worsens, dandruff appears, the smell of the animal may change. These symptoms are non-specific,they can also be observed in other diseases. Symptoms of infection in young animals, especially dogs, are much more pronounced. Puppies squeal, bark for no reason, bite, lose weight, their hair grows a lot. Appetite disorders, flatulence, diarrhea, vomiting are characteristic. When vomiting, toxocars are often thrown out of the intestines in whole tangles. Sick puppies lag behind in growth and development. The migration of larvae through the lungs leads to the development of pneumonia and pulmonary edema. Adult worms in the small intestine cause inflammation of the intestinal mucosa. Accumulations of worms can cause intestinal obstruction with the development of peritonitis. All this often leads to the death of all or part of the droppings. Animals are diagnosed after copro-ovological analysis. However, it must be borne in mind that we have adopted in veterinary medicine, and in medicine,the methods of such analyzes are extremely primitive and do not always allow detecting infection. To prevent toxocariasis, it is recommended to treat dogs every 2 months. For domestic cats, an annual autumn treatment for all helminths is sufficient. It is imperative to treat toxocariasis before mating. Now in veterinary pharmacies there is a large arsenal of drugs against parasitic nematodes, which are toxocars. These are piperazine salts, levamisole (nilverm, decaris), pyrantel, febantel (rintal), mebendazole, febendazole, azipirine. For young animals there is a drug called Drontal Junior. All these drugs kill intestinal parasites well. The larvae sitting in the internal organs are destroyed much worse. The deworming of young animals requires special attention. Due to the high probability of infection, even in the absence of severe symptoms of toxocariasis,the first deworming is recommended at the age of 3 weeks. If the symptoms of infection are present, it is advisable to carry out deworming under the supervision of a veterinarian, since it is unsafe for an animal weakened by worms. In addition to the actual toxic effect of drugs, toxins are added, secreted into the body by dying worms. Therefore, deworming is combined with detoxification and restorative therapy. People also get toxocariasis. Practitioners usually do not know anything about this disease, which is becoming more widespread. A person becomes infected with toxocariasis in all the same ways as animals. But in our country, intestinal forms develop extremely rarely, usually toxocar larvae affect only internal organs. This is visceral toxocariasis. Ocular toxocariasis develops when the larvae enter the eyes, it leads to a decrease in vision, the development of inflammatory diseases of the eye, even to blindness. Since toxocara is a nonspecific parasite for humans, this disease causes much more serious consequences for us than for animals. Children are especially often infected with toxocariasis. Usually, patients with toxocariasis are treated for years by a variety of specialists, up to oncologists, before they can make the correct diagnosis. Cases of fatal visceral toxocariasis have been reported. In St. Petersburg, in some clinics, toxocariasis is detected by the immunological method. For the spread of toxocariasis, compliance with the rules for keeping animals is of great importance. It is not customary for our dog breeders to remove feces. As a result, the soil of St. Petersburg has accumulated a huge supply of eggs of these parasites. Usually, the owners of dogs justify themselves by saying that there is nowhere to throw this stuff away, or they say that the dirt in the city is from people no less than from dogs. Yes, many of our fellow citizens have got into the habit of shitting in the same place where they eat. However, there is still a difference: empty bottles, chip wrappers and other rubbish do not infect us with anything. Therefore, I would like to appeal to all dog owners: let's all take care of ourselves, our children and grandchildren, as well as dogs. Let the tradition of the civilized keeping of animals originate in St. Petersburg - the cultural capital of Russia.empty bottles, chip wrappers and other rubbish do not infect us with anything. Therefore, I would like to appeal to all dog owners: let's all take care of ourselves, our children and grandchildren, as well as dogs. Let the tradition of the civilized keeping of animals originate in St. Petersburg - the cultural capital of Russia.empty bottles, chip wrappers and other rubbish do not infect us with anything. Therefore, I would like to appeal to all dog owners: let's all take care of ourselves, our children and grandchildren, as well as dogs. Let the tradition of the civilized keeping of animals originate in St. Petersburg - the cultural capital of Russia.