Vlasoyed in dogs

The dog lice (Trichodectes canis) causes the disease trichodectosis. The parasite Trichodectes canis belongs to the order Mallophaga chewing lice. Chewing lice feed on skin scales (epithelial debris) and hair. There are also some species of lice of the genus Mallophaga, which have mouthparts and are able to feed on the blood of animals; in cases of severe infection, this can lead to anemia, weakness and malnutrition, especially in young dogs, puppies and toy breeds.

Vlas-eaters are sedentary insects of a milky color, which can be quite difficult to notice with the naked eye on the body of an animal. Trichodectes canis has a flat body, reaching a maximum length of 2 mm. Vlas-eaters do not have pronounced localization sites – adult parasites and tightly attached lice eggs (nits) can be found along the entire length of the hair on the entire surface of the body. Vlas-eaters are able to reproduce very quickly, increasing their population exponentially in a short time. Just one female is able to lay 60 to 70 eggs in a few days. The larvae hatch from the eggs at intervals of 14 to 20 days. Vlas-eater larvae quickly become adults and are capable of self-feeding and reproduction after one molt. The source of food for lice eaters are skin particles, wool, as well as blood and lymph from the surface of the injured skin.

Vlice-eaters in dogs are strictly species-specific parasites – a dog louse cannot live on a cat or a person, and a louse that parasitizes a person is not dangerous for pets.

Photo of lice in dogs

This is what a lice looks like in dogs (Photo: veteracenter.ru)

Photo of a lice in dogs

The danger of withers for dogs

The consequences of infection can be quite serious. In addition to the harm that lice directly cause to an animal with their vital activity, they often become intermediate hosts of helminths and pose a danger as a natural reservoir of internal parasites. Also, parasitism of the lice contributes to the development of various skin infections. The most serious risk when parasitizing Trichodectes canis on a dog is infection with cucumber tapeworm. Cat and dog lice eaters, like fleas, are intermediate hosts of the tapeworm Dipylidium caninum. A dog becomes infected by ingesting an infected parasite while biting the fur while trying to get rid of the intense itching caused by the parasites. People who are in close contact with pets can also become infected with dipilidiosis. Infection with lice can lead to severe exhaustion of the dog. Animals cannot eat properly, become nervous, cannot sleep peacefully. Puppies may lag behind in growth and development, gain weight poorly. With severe infestation, dogs can develop anemia. The parasitic activity of the lice leads to secondary skin problems. Self-injury during scratching leads to inflammation of the skin and can be complicated by pyoderma (reproduction of microflora on the dog’s damaged skin). During scratching and biting, the dog damages the skin, open wounds form, into which microbes living on the skin and pathogenic microorganisms enter.

Ways of infection

Infection with trichodectosis most often occurs during close communication between animals, during walks, games, and training. The source of infection is the carrier animal. But infection is also possible through contact with contaminated objects, bedding, surfaces on which a parasite-infected dog lay. Puppies are most vulnerable to infection with lice. They can become infected from bitches, and even at home, in contact with street shoes. Most often, withers are found in shelters, kennels and damp, poorly adapted premises for keeping animals. Increased crowding of animals promotes close contact and increases the risk of infection.

Signs and symptoms of infection

At the initial stage of the disease, trichodectosis may not be clinically manifested, and symptoms of infection with lice in dogs may be mild. Sometimes infection can be manifested by slight skin peeling. But as the parasite population increases, the dog begins to feel restless, itching intensely, rubbing against hard objects, rolling on the ground, trying to relieve severe itching. On wool you can see nits, dandruff, scratching. Wool becomes visually dirty, greasy, has an unhealthy and untidy appearance. Hair becomes brittle and dull. With a prolonged illness, tangles can form, in places of a large accumulation of parasites, extensive areas devoid of wool appear.

Outwardly, nits on the coat may at first glance look like dandruff, since the parasite is very small. Due to damage to the skin due to severe itching, inflammation develops on it, papules appear, covered with crusts. There may be signs of dry seborrhea and peeling of the skin.

Clinically, flea infestation in dogs may resemble flea allergy dermatitis. It is important to consider that an animal can suffer from both fleas and lice at the same time.

The main method for detecting lice in dogs is a thorough examination of the skin of the animal. Detection of the parasite is the basis for diagnosis and treatment.

Vlas-eaters have an interesting feature – this phenomenon is called thermotropism. Withers love heat, and when the dog is warmed up in direct sunlight or when the wool is heated with an electric lamp (to a temperature comfortable for the animal), the withers move closer to the surface of the coat, where it becomes easier to detect them with the naked eye. Well helps in the diagnosis and the usual magnifying glass.

Trichodectosis in dogs must be differentiated from another parasitosis – scabies. Taking skin scrapings and examining them microscopically helps the doctor make an accurate diagnosis. Careful diagnosis allows you to treat the dog from the lice most effectively.

Although lice are easy enough to detect, they are difficult to remove from the surface of the pet’s hair, since the female lice, when laying eggs, attaches them very firmly to the animal’s hair with their sticky, glue-like glandular secretion. Therefore, it is almost impossible to wash off the egg nits during bathing, it is difficult to remove them mechanically with tweezers, they do not fly off the dog during even the most intense movement. Therefore, one of the most important methods of dealing with withers is a haircut. Grooming is a very good helper in the fight against withers, it is a necessary medical procedure, especially for animals with long hair. If it is impossible to cut the show animals, they will have to be combed out daily with a fine comb and manually remove the nits from the wool. For these purposes, tweezers are useful.

Treatment procedures also include daily care, as well as combing the hair with a fine comb and bathing with medicated shampoos containing parasicidal agents.

Treatment of dog infection with lice

The main method of treatment for lice in dogs is the destruction of parasites with the help of insectoacaricidal agents. To destroy the larvae, use the means that are used to treat flea infestation. Apply drops and sprays with fipronil, selamectin, imidacloprid (used only for dogs, toxic to cats), pyriprol (used only for dogs and not used for cats) and other antiparasitic agents that are used to combat external ectoparasites. Processing is carried out with an interval of 14 days.

It is important not to use ectoparasite treatments containing pyrethroids on dogs and indoors if a cat lives in the home with the dog, as pyrethroids are toxic to cats and can cause severe poisoning in them. In order to get rid of the lice eater, it is necessary to carry out a thorough treatment of the external environment – the space where the dog lives.

To prevent recurrence of the disease, all animals in contact with a dog infected with lice should be treated, despite the fact that not all animals living with an infected dog have clinical signs of the disease. Since the entire life cycle of the lice lasts from 14 to 21 days, the treatment should continue for at least 14 days, and bathing with medicated shampoo is carried out over the next 14 days after the main course of treatment. On average, a full course of treatment lasts about 30 days.

Since lice often affect puppies, when choosing a drug, it is important to take into account not only body weight, but also the age of the babies. When infecting small puppies or kittens, pregnant, lactating, malnourished or convalescent animals, it is important to use a special remedy that is approved for the smallest and debilitated patients. As a rule, in such cases, sprays or drops based on fipronil are used.

Vlice eaters are usually easily killed by insecticides, so getting rid of them is usually not difficult. If the dog is kept in an apartment, then at the beginning of the course of treatment, bathing with an antiparasitic shampoo is used, and after 3–5 days, a flea and tick preparation is applied in the form of drops to the withers. When bathing a dog, it is important to hold the foam of the therapeutic shampoo on the coat for at least 5-7 minutes.

Prevention

To reduce the risk of infection and prevent trichodectosis in dogs, it is important to conduct regular preventive examinations of the skin and coat of the pet. It is important to observe the hygiene of places where animals are kept, regularly process and wash bedding, blankets, ammunition (leashes, collars, muzzles), and disinfect animal care items. It is undesirable to use someone else’s pet care accessories, beds, bedding, exhibition cages and boxes for transportation. It is important not to forget to follow the rules of hygiene when visiting exhibitions and in contact with other animals.

Try to limit the contact of decorative dogs with street shoes and clothes if the pets are kept year-round in an apartment or house and do not have regular walking. This reduces the risk of infection by parasites among toy breed dogs.

Regular treatment against fleas and ticks reliably protects animals from infection. Insectoacaricidal preparations are mistakenly used only in the warm season. Therefore, it is important to carry out regular treatment with antiparasitic drugs all year round to eliminate the risk of infection with lice in late autumn and winter.

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October 2 2020

Updated: February 13, 2021