Toxocara (toxocara Canis): Symptoms, Treatment In Adults And Children, Cats And Dogs

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Toxocara (toxocara Canis): Symptoms, Treatment In Adults And Children, Cats And Dogs
Toxocara (toxocara Canis): Symptoms, Treatment In Adults And Children, Cats And Dogs

Video: Toxocara (toxocara Canis): Symptoms, Treatment In Adults And Children, Cats And Dogs

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Video: Toxocariasis in dog Part 1 2023, February
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  • Are toxocars worms?
  • Development life cycle
  • Can the parasite affect the liver and eyes?
  • Are the larvae and eggs of toxocara seen in feces in humans?
  • Toxocara in adults: signs of infection and how to treat
  • Toxocara in children: symptoms and treatment
  • Diagnostics
  • ELISA of blood for IgG antibodies: positive, negative and what does it mean
  • Toxocars in cats and dogs
  • You can defeat parasites!

Toxocara is a helminth that causes toxocariasis, the most common helminthic disease in our country.

Are toxocars worms?

Toksokars are divided into the following types:

What to do in such a situation? To get started, we recommend reading this article. This article details the methods of dealing with parasites. We also recommend contacting a specialist. Read the article >>>

Toxocara canis, which is carried by dogs

Toxocara canis
Toxocara canis
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Toxocara cati, which is carried by cats

Toxocara cati
Toxocara cati
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Toxocara vitulorum, which is carried by cattle (cows, buffaloes)

Toxocara vitulorum
Toxocara vitulorum
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These worms belong to nematodes (round worms). The most common type is toxocara canis. These worms are heterosexual, and females significantly exceed males in body length: 6-18 cm in females and 4-10 cm in males.

The body color is yellowish. The mouth opening has three lips; on the "head" end of the body there are bulges, similar to a kind of "wings", the size of which is carried out differential diagnosis with other helminths, in particular, with roundworms (see photo).

Appearance
Appearance
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Toxocara under high magnification

Toxocaras lay very small round brown eggs, 65-75 microns in size. Eggs have a dense outer shell, and inside, if the egg is sufficiently formed, a mobile larva. If the formation of the egg has not yet been completed, then instead of the larva, there is a spherical embryo inside the egg.

Toxocara eggs
Toxocara eggs
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Toxocara eggs

Toxocariasis is a geohelminthiasis, since the eggs mature and are on the ground before reaching the host. The natural carriers of this helminth include predators of the feline and canine families (dogs, foxes, etc.), acting as the final hosts, while humans are intermediate hosts for toxocaras.

Development life cycle

The full life cycle of Toxocara is only possible in the body of the final host. Eggs are able to remain viable in the soil for years, so animals become infected very easily. It takes about a month for the eggs to ripen, but if the temperature and moisture of the soil are optimal for their development, then the ripening period can be reduced to one week.

After being swallowed by animals, the eggs enter the intestines, where larvae appear from them, which then penetrate into the blood vessels and are carried with the bloodstream throughout the body, and during their migration, various organs and systems can be damaged.

If the larvae enter the lungs and trachea, the animal, due to the cough reflex, "coughs" them out, but some part remains in the oral cavity and is swallowed back. Through the esophagus, the larvae reach the intestines - the place of their localization. Here they are formed up to adults. The female Toxocara is exceptionally fertile: she is able to lay up to 200 thousand eggs per day.

Development life cycle
Development life cycle
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Development life cycle

In humans, toxocaras can only parasitize at the larval stage. Infection occurs through the oral route. After the eggs enter the proximal part of the small intestine, larvae appear from them, which penetrate through its mucous membrane into the circulatory system. The bloodstream carries the larvae to the liver and heart, then through the small circle of blood circulation they enter the large one, and through it they migrate to all organs and tissues.

Can the parasite affect the liver and eyes?

While migrating, the larvae can be localized in the liver, heart, lungs, eyes, brain, muscles, pancreas, and they can maintain their viability for years without any symptoms. The activation of the parasite occurs, as a rule, with a sharp decrease in immunity; if this does not happen, then the larvae are encapsulated and die.

Parasite in the eye
Parasite in the eye
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Parasite in the eye

Are the larvae and eggs of toxocara seen in feces in humans?

In the human body, toxocars are not localized in the intestines, so they will not be in the feces either. That is why it is impossible to diagnose toxocariasis based on the analysis of feces. Migratory larvae are also extremely difficult to detect. However, an immune response occurs to the parasite, so the most reliable diagnostic method is to detect antibodies.

Toxocara in adults: signs of infection and how to treat

The symptoms of toxocariasis in humans are so diverse and often similar to the symptoms of other diseases that it is almost impossible to make a correct diagnosis based on them. The larva, migrating with the bloodstream, can end up in any organ, which will cause the corresponding symptoms.

Blood test for worms
Blood test for worms
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It happens that toxocariasis gives an allergic reaction in the form of a rash, bronchial asthma, Quincke's edema. The most reliable diagnostic method is considered to be an enzyme-linked immunosorbent assay for antibodies (ELISA).

Toxocariasis is diagnosed using a special test based on a general blood test. Proper treatment will protect a person from complications, which are most often very difficult to respond to standard therapy.

The clinical manifestations of toxocariasis are due to the intensity of the body's immune response, the degree of its infection and the localization of the helminth. Often, the disease is generally hidden or sluggish, with alternating exacerbations and remissions, for several months or years. Fatal outcome is rare only if vital organs are affected: heart, central nervous system, etc.

Depending on the symptoms, toxocariasis is divided into the following forms:

  • ocular;
  • visceral;
  • skin;
  • neurological.

With the localization of toxocara in the eye, the following clinical manifestations develop: uveitis, chronic endophthalmitis, optic neuritis, keratitis, granuloma, pars-planitis, the presence of migrating larvae in the vitreous body, abscess. With damage to the optic nerve, complete loss of vision is possible.

Severe ocular toxocorosis
Severe ocular toxocorosis
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Severe ocular toxocariasis

Visceral (systemic) toxocariasis is more common in children than in adults, and develops with massive invasion of parasites. It is characterized by fever (with lung damage), an increase in liver size, eosinophilia, lymphadenopathy, hypergammaglobulinemia and pulmonary syndrome, which occurs in 65% of cases and is accompanied by such phenomena as bronchitis, recurrent catarrh of the respiratory tract, bronchopneumonia.

Lung damage is accompanied by dry cough, mainly at night, shortness of breath, cyanosis, moist wheezing. If treatment is not started on time, pneumonia can develop, and in severe cases, death is possible.

Cutaneous toxocariasis manifests itself mainly in the form of allergic reactions: urticaria, eczema and skin rashes with redness, swelling and excruciating itching, which are most visible during the migration of larvae.

Enlarged liver due to parasites
Enlarged liver due to parasites
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Enlarged liver due to parasites

Neurological toxocariasis develops if the larvae of the parasite enter the central nervous system; at the same time, various neurological disorders can be observed in combination with changes in behavior: memory impairment, obvious difficulties in reading, hyperactivity.

Treatment of toxocariasis is carried out with the following anthelmintic drugs: Vermox, Mintezol, Ditrazine citrate, Albendazole, Vermox. It should be remembered that any medicine for worms is more or less toxic and can cause unpleasant side effects. In addition, when helminths die, many toxins are released, which also causes a deterioration in well-being.

Toxocariasis of the brain
Toxocariasis of the brain
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Toxocariasis of the brain

Toxocara in children: symptoms and treatment

Most often, toxocariasis is diagnosed in children from one to 14 years old, living mainly in rural areas, although city children are often infected with toxocara eggs when playing on the street, in a sandbox, etc., as well as from pets.

Toxocara in children
Toxocara in children
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The disease usually proceeds for a long time, with the appearance of relapses. Although it is believed that toxocariasis causes dangerous consequences for the health of a child in rare cases, in the visceral form - lung damage, pneumonia may develop, even fatal.

According to Dr. Komarovsky, there is no specific therapeutic tactics on how to treat this widespread disease. The problem is that anthelmintic drugs only affect migratory larvae and are harmless to encapsulated ones.

Komarovsky emphasizes that only narrow specialists should deal with the treatment of toxocariasis, since this process is long, and potent drugs can cause unwanted side effects in a child.

The symptomatology of toxocariasis in children is due to the form of the disease.

  • In the visceral (systemic) form, the disease is accompanied by fever, persistent eosinophilia, pulmonary syndrome, breathing problems up to the development of pneumonia, swollen lymph nodes, spleen and liver, pain in the abdominal cavity; toxins released by toxocars in the process of life, cause nausea, vomiting; bloating, diarrhea.
  • With the cutaneous form, the nail plates and hair become thinner, a rash, inflammation and itching appear on the skin; allergic reactions occur in the form of dermatitis, urticaria, eczema; on the palms and feet under the skin, the formation of small nodules is possible, where toxocara larvae are localized.
  • With the ocular form, the optic nerve becomes inflamed, chronic endophthalmitis, uveitis, granuloma occurs.
  • With the neurological form of toxocariasis, noticeable disturbances in thinking and memory occur; with brain damage, convulsions, epilepsy, paralysis may occur; sleep disturbances; there is a strong excitability, irritability, hyperactivity.

Treatment of toxocariasis in children is carried out with the same medications as in adults, with an appropriate dosage adjustment. As a rule, the course of treatment is repeated (strictly according to the doctor's prescription) after 3 months. In severe cases, 5-6 courses may be required. Duration of treatment is up to 3 years.

Vermox is considered the most preferable for the treatment of children, since it has low toxicity. Despite this, Vermox sometimes causes a decrease in appetite in the child, nausea, diarrhea, and severe weakness.

Take a toxocar test

Symptoms Answer Bronchial asthma Yes Not Quincke's edema Yes Not Abscess Yes Not Fever Yes Not Increased liver size Yes Not Hives Yes Not Eosinophilia Yes Not Pars Planite Yes Not Eczema and eruptions on the skin with redness Yes Not Headaches Yes Not

Diagnostics

To make a preliminary diagnosis, the doctor needs to find out:

  • anamnesis, including the presence of pets (dogs, cats), frequency of contact with soil and outdoor animals;
  • severe symptoms;
  • the presence of eosinophilia.

As shown above, stool analysis does not provide information on toxocara infection. The best option is an enzyme-linked immunosorbent assay (ELISA), the accuracy of which is up to 95%. For the final diagnosis, a biopsy (mainly of the liver) is often prescribed in order to detect the larvae of the parasite.

In the ocular form of the disease, diagnosis should be carried out with the involvement of an ophthalmologist, since with this form of eosinophilia may be insignificant or absent altogether, as well as the presence of specific antibodies in the blood.

Serological studies may also not give reliable results: if the result is positive, this may be due to the presence in the body of helminths similar to toxocaras, and a negative result is obtained due to the small number of toxocara larvae and their localization in the eye.

ELISA of blood for IgG antibodies: positive, negative and what does it mean

Among serological studies, ELISA is considered the most reliable, since it can be used to determine whether there are antibodies in the blood to antigens of certain parasites. Positive result - if the igg titer is higher than 1: 200; values ​​from 1: 200 to 1: 400 indicate the presence of toxocara in the body, and antibody titers above 1: 600 indicate the development of the disease and the need for urgent treatment.

Toxocars in cats and dogs

Toxocars in cats and dogs are a very common phenomenon and a source of infection for humans. The eggs of the parasite enter the body of animals from the soil, when they eat raw meat and even earthworms. Another way is intrauterine infection, when the larvae cross the placenta and infect the fetus. Toxocara can enter the baby's body with breast milk.

The entire cycle of development of sexually mature individuals from an egg takes 3 weeks in the animal's body, therefore, toxocariasis can be diagnosed in puppies that become infected intrauterinely after 3 weeks.

As a rule, in adult cats and dogs, symptoms of the disease do not appear, and in puppies and kittens the signs of infestation are as follows:

    • restless behavior, bite;
    • diarrhea and vomiting, in which toxocar tangles sometimes come out;
    • bloating;
    • perverted appetite;
    • poor weight gain;
    • developmental lag.

Kittens become infected through their mother's milk. In addition to these symptoms, they may experience dehydration and dry cough; eyes sink and water; the mucous membranes turn pale.

Only a veterinarian will give qualified advice on how to get rid of toxocariasis - self-medication can negatively affect the animal's body. It is necessary to treat toxocariasis in animals, as children and people with weak immunity can become infected with it.

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