In our article we will talk about such diseases as dirofilariasis. The ailment was previously common in tropical countries. But now he is confidently moving to the northern states. The causative agent of the disease has already adapted to cold temperatures. Therefore, the disease is more often registered in the states of Eurasian content. Pet owners need to know how to recognize the disease, as well as how to treat dirofilariasis in dogs. But first we will consider the ailment itself and its stages.
Biological and general characteristics of nematodes. Description of the disease
Dirofilariasis is a zoonotic, transmissible, invasive disease. The disease is characterized by heart, liver and pulmonary complications. In this case, the worms do not affect the intestines. The causative agents are nematodes of the Onchocercidae family:
- Dirofilaria immitis. It is usually parasitic in the hollow veins, the right ventricle of the heart, and the pulmonary artery.
- Dirofilaria repens. Usually parasitic in the subcutaneous tissue of different parts of the body.
The dogs of dirofilaria repens and dirofilaria immitis in dogs are mosquitoes. Infection occurs through a bite. All breeds are affected, regardless of size, age, and gender. Mosquitoes are intermediate carriers of helminth.
In the intestine of the insect worms are day. Then they are moved to malpighiev vessels. After that, the development process takes place within 16 days. Then microfilariae are introduced into the body of a mosquito, lingering on the lower lip. After that, the larva reaches a length of up to 0.9 mm and through the proboscis of a mosquito enters the blood of a warm-blooded animal (in this case, a dog).
Stages of the disease and its types
After a few weeks, a larva develops in the subcutaneous space of an infected animal. Now there is a transformation of the helminth into an invasive individual, which can already move to a new organism. In the fifth stage, the parasite can penetrate the heart and vessels of the dog. And after six months inside the body begins an active reproduction of the helminth.
The maximum size of an adult parasite is 30 centimeters. Due to the spread of helminths through the body of the animal, the work of the internal systems and organs is disrupted. If the treatment of dirofilariasis in a dog has not been started in time, it will simply die.
If we talk about which form of the disease is easier, then it is skin. In this case, usually there is no death. The skin form of the disease is manifested: itching, skin rashes in the neck and muzzle.
Symptoms of the disease
How to understand that a dog has heartworms? How the disease manifests itself depends on how much the parasite is in the animal's body. As the helminth develops, it moves into the internal organs, after which it begins to grow in them. If it is parasitic in the vessels, penetrating through them into the heart, then the animal's blood flow is disturbed, as a result of which heart failure can develop. You can be suspected of the following symptoms of dirofilariasis in dogs:
- swelling of limbs
- weak cough
- labored breathing,
- instead of sputum observed blood discharge.
Also with this disease there is a loss of appetite, papular dermatitis on the paws and head, as well as general malaise. You can also notice the rapid fatigue and apathy of the animal. Periodically, the dog is subfebrile temperature, as well as fever. A similar condition in an animal arises due to the negative impact on the body of the products of parasite life.
Danger of illness and possible complications in the treatment of an animal
What is dangerous disease and what could be the consequences of dirofilariasis in a dog? With this disease the animal develops tachycardia, the arteries of the lungs are deformed. The disease is fraught with the development of irreversible processes in the vessels, heart and lungs:
- There are noises in the heart.
- There is tachycardia.
- The pulmonary arteries are enlarged and deformed.
- The right parts of the heart expand, thereby interfering with the normal functioning of the body.
- Increases pulmonary artery density.
- Disturbed blood supply to the lungs.
- The central pulmonary artery bulges out.
- Gradually, such complications as liver and kidney failure develop.
Of particular danger is the death of the helminth in the animal. The dead parasite decomposes, shifts to the distal borders of the pulmonary arteries. The presence of their fragments in the vessels leads to the accumulation of platelets and pulmonary embolism.
Approximately 15% of dogs that have this parasite inside, suffer from diseases such as glomerulonephritis. Helminths can also penetrate the abdominal cavity, the brain and spinal cord, as well as the eyes.
Methods for diagnosing disease in dogs
There may be a suspicion of infection with this helminth, if the animal visits the endemic zone during the summer period. Those who love to travel to warm countries with a pet, and subject him, and themselves at risk of infection. In this case, the disease in a pet can not be suspected for several months or even years. Due to the variability of symptoms, the process of identifying the disease is complicated. To put an accurate diagnosis at home just will not work.
For this you need to undergo various medical examinations. These procedures include:
- smear analysis according to the Romanovsky-Giems method,
- immunological tests for dirofilariasis in dogs
- peripheral blood antigen test
- Schuffner’s blood test,
- electrocardiography. Gives the opportunity to identify heart problems.
If we talk about immunological analysis, then the main tool in it is a one-time test for rapid diagnosis. They can detect protein - antigen, which is secreted by adult females of the parasite. The accuracy of the test depends on the number of individuals in the animal. If one instance is found, then the sensitivity of the test will be no more than 64%.
If the fact of the presence of microfilariae in the blood is confirmed, then it is necessary to establish further what type the helminth belongs to. It is determined by histochemical staining.
Difficulties in diagnosing this disease
There are false negative results in the diagnosis of the disease. Why is this happening? Errors can occur for a number of reasons:
- The absence of parasites in the blood, due to the rapid penetration into the pulmonary artery.
- The population consists of their males.
- The number of worms is very small.
It is possible to obtain a false negative test result due to the fact that the animal was given an anthelmintic drug.
The first stage of treatment of the animal
If heartworms are found in a dog, therapy should begin immediately. Treatment consists of two stages. The first is the destruction of parasites. In this case, apply special medications. What drugs are used to treat dirofilariasis in dogs? The medicine "Filarsen" kills adult parasites. Give the drug for ten days. Dosage: 0.001 g per 1 kg of body weight three times a day.
Levamisole is also used. The instructions indicate that the drug is effective in the early stages of the disease. Destroys the means of larvae and males, but it does not affect females at all. The instructions "Levamisole" indicated that the drug is administered subcutaneously at a dose of 1.0 ml per 10 kg of animal weight.
Also used to treat dirofilariasis in dogs "Diethylcarbamazine." The drug acts quite effectively on the larvae. Duration of treatment is 1 month. Dosage - to 0.025 g of the drug per 1 kg of animal weight 3 times a day.
Also used for the treatment of medicine "Ivermectin." The instructions for use indicate the following dosage - 0.2 ml per 1 kg of weight. The injection of the drug is done subcutaneously 1 time per month. The instructions for use of "Ivermectin" also indicated that the drug is very effective. He destroys microfilariae within 24 hours.
There is another drug that is used for dirofilariasis - this is "tiacetarsamid." It is prescribed in the following dosage - 1 mg per 1 kg of dog weight. To administer the drug twice a day intravenously. Duration of therapy is 15 days. After a few months it needs to be repeated, since the drug affects only adult parasites that die during the first week. "Thiacetarsamid" is considered to be quite effective against this type of worms. But after the first course is unlikely to complete cure. At least two are needed, and it is necessary to periodically monitor the effectiveness of therapy with the help of serological methods and blood tests.
Note that a drug such as "Thiacetarsamide" is toxic. It can cause hepatorenal dysfunction, skin necrosis and pulmonary embolism with dead worms. Therefore, the following biochemical blood parameters should be monitored: serum creatinine, liver enzyme activity, blood urea nitrogen. Also, periodically you need to do to control urine analysis. To prevent tissue necrosis at the injection sites, make lotions with dimexide (1: 6 with water).
Second stage of therapy
The second stage of dirofilariasis treatment in dogs is aimed at reducing the pathological effects of parasites, as well as at overcoming hypoxia. In severe cases, you need three or four days to hold the animal under an oxygen mask. If the internal organs are severely affected, then surgery is usually used. During surgery, parasites can be extracted in two ways. In the first case, the procedure is carried out with special forceps. You can also perform the operation through the vena cava.
For the prevention of thromboembolic complications (thrombus formation), acetylsalicylic acid with heparin, dipyridamole or ticlopidine is injected into the animal's blood during therapy.
If the animal has a skin form of the disease, then macrolides are used in small doses. The duration of dirofilariasis treatment in dogs varies from eight months to three years. That is, until such time as all adult individuals are destroyed. If skin reactions are observed, then specific drugs are prescribed for symptomatic treatment.
During the period of therapy, it is desirable to isolate the sick pet in a separate aviary and room. During treatment, short walks are allowed, but without special physical exertion.
Infection of the disease occurs very easily. But to prevent this is simple, you just need to carry out preventive measures. It is necessary to treat the animal with one of the following preparations:
- "Ivermetin" ("Baymek", "Ivomek", etc.),
They belong to the group of macrolides, effective and safe for the animal. Prevention can be performed on dogs older than 2 months. Before vaccination at seven months, it is necessary to diagnose the presence of these parasites in the animal.
Components such as moxidectin and imidacloprid are contained in such a popular drug as “Advocate” (drops on withers). The tool affects the larvae.
Additional measures are the treatment of animal repellents, as well as the use of fumigators and mosquito nets in the premises.
It is advisable in the warm season to do a test for dirofilariasis to your pets, in order to identify the ailment at an early stage and not allow pathological changes to develop. Then the treatment will be much easier.
Now you know how dirofilariasis in dogs manifests itself, what is dangerous about this disease. In our article, we examined in detail the treatment options for this ailment. Remember that early diagnosis avoids the consequences. Therefore, do not forget to check your dogs for the presence of parasites or at least monthly (during the period of the appearance of mosquitoes) it is worth carrying out preventive treatment.
Information about the disease and the stage of development of dirofilaria
Dirofilariasis - larval (extra-intestinal) helminthiasis, in which the nematode larva, which has not reached puberty, parasitizes the animal's body. Helminth hawkers are mosquitoes that previously lived exclusively in countries with a warm climate. Recently, the disease is registered in a temperate climate and countries located to the north.
Dirofilariasis is a disease that is spread by mosquitoes. Large accumulations of these insects are observed near water.
Infection with diphylaria occurs through a mosquito bite in the summer. Dogs of all ages and breeds are susceptible to the development of the disease: from small (Bichon Frize with photos) to large and giant (description of the South African Boerboel). Mosquitoes are intermediate carriers of helminth, they swallow the larvae-microfilariae during bloodsucking.
The larvae are in the intestines of the insect day, then moves to malpighian vessels. Within 16 days they develop, then penetrate into the body of the insect and linger on the lower lip. Having reached there the length of 0.8-0.9 mm, the larva enters the blood of the warm-blooded animal through the proboscis.
The development of larvae ends in the subcutaneous space of the animal for several weeks. The helminth turns into an invasive individual, capable of moving into a new organism. In the fifth stage, the worms penetrate the vessels and the heart of the wearer. Six months later, their active reproduction begins inside the body.
The size of adults of dirofilaria can reach 30 centimeters. Their distribution in the body of the animal disrupts the functioning of internal organs and systems. Without treatment, dirofilariasis leads to the death of the dog.
The size of adults of dirofilaria can reach 30 centimeters. Their active growth occurs in the heart and vessels of the dog.
A relatively mild form of diphylaria is skin. This form does not lead to death. Manifested in the form of skin rashes mainly in the area of the muzzle and neck, itching.
Symptoms of dirofilariasis
The manifestation of dirofilariasis depends on the duration of the helminth in the dog. As it grows, the helminth penetrates the internal organs and begins to grow in them. Parasitizing in the dog's vessels and penetrating through them into the heart, the helminths interfere with the blood flow to the heart, developing heart failure.
The disease can be suspected by the presence of the following symptoms:
There is also general malaise, loss of appetite, papular dermatitis on the head and feet. The dog becomes apathetic, quickly tired. Periodically observed febrile phenomena, subrefilnom temperature. These symptoms develop due to the negative impact on the animal's organism of the waste products of nematodes.
Danger of the disease and possible complications
Dirofilariasis is dangerous by the development of irreversible processes in the lungs, heart and vessels of the dog:
- The pulmonary arteries increase and deform, their density increases.
- The right heart expands, disrupting the organ.
- Central pulmonary artery bulges.
- There are noises in the heart, tachycardia.
- Pulmonary vascular pattern is impoverished, blood supply to the lungs is impaired.
- Gradually develop complications in the form of renal and hepatic failure.
A specific danger is the natural death of the parasite in the dog's body. Parts of dead helminths decompose and shift to the distal pulmonary arteries. The presence of fragments in the vessels causes platelet aggregation and causes pulmonary thromboembolism.
In 14% of dogs infected with dirofilaria, glomerus nephritis is affected. Parasites are able to penetrate into the spinal cord and brain, eyes, abdominal cavity.
Diagnostic methods for dirofilariasis
Suspicion of dirofilaria invasion in the dog’s body occurs if the owner has visited the endemic zone during the flight of mosquitoes. Fans of traveling to warm countries with a pet are at risk of infecting themselves and the dog. In this case, the owner may not suspect the pet's illness for several months or even years. The difficulty of diagnosis arises also in connection with the variability of symptoms.
Making a diagnosis of dirofilariasis at home is impossible. The main symptoms require confirmation with a medical examination.
A variety of procedures or activities are being conducted:
Electrocardiography will allow time to identify heart problems in dogs.
- testing for peripheral blood antigen,
- smear analysis according to the Romanovsky-Giems method,
- Schuffner’s blood test,
- immunological analyzes.
The main tool for immunological analysis is a one-time rapid diagnostic test that detects a protein, an antigen secreted by adult helminth females. The accuracy of the test depends on the number of adult females in the dog's body. При наличии всего одного экземпляра чувствительность теста составляет не более 64%.
При обнаружении микрофилярий в крови необходимо установить их принадлежность к определённому виду. Высокопатогенными являются D. immitis и D. Repens, их обнаруживают с помощью гистохимического окрашивания.
Трудность диагностирования болезни
When diagnosing dirofilariasis in some cases, false-negative results are recorded. Sometimes diagnostic methods do not allow to identify the helminth in the animal.
The error occurs for the following reasons:
- The number of parasites is too small.
- The rapid penetration of the helminth into the pulmonary arteries and their absence in the blood.
- The population consists of males.
Obtaining false negative results of dirofilariasis is possible even if the dog has previously received a dose of anthelmintic drugs. The analysis will be blurred, the diagnosis is inaccurate.
Dirofilariasis - a threat to human health
Human infection with dirofilariasis is also possible, but this happens through a mosquito bite, and not while caring for a sick dog. A sick animal is not dangerous for the owner.
A person cannot become infected with dirofilariasis from his pet, since infection occurs only through a mosquito bite.
At the same time, there is a theoretical possibility of transferring the helminth larvae using a mosquito bite. An insect that has bitten an infected dog, and then biting a person, carries the larvae into its body. Of course. The risk of such a route of infection is negligible, but still possible.
Treatment of dirofilariasis in dogs
Therapy for dirofilariasis in dogs consists of two compulsory stages.
The first - the destruction of worms in the body. For these purposes, the following drugs are used:
- Philarsen. Kills adult individuals. Dog give 0,001gr. drugs per kilogram of weight for 10 days.
- Diethylcarbamazine. It affects the larvae. Assigned to 0.025 grams. drug per kilogram of weight 30 days.
- Levamisole. Effective in the early stages of the disease, kills males and larvae. Does not act on females.
The second is the reduction of the pathological influence of helminths on the body, overcoming hypoxia. In especially severe cases, the dog must be kept under an oxygen mask for several days, and if the internal organs are severely damaged, surgical intervention is used.
For the prevention of thromboembolic complications during the treatment of helminthiasis, acetylsalicylic acid with dipyridamole, ticlopidine or heparin is injected into the dog’s blood.
Acetylsalicylic acid is used to prevent the formation of blood clots during the treatment of dirofilariasis.
Skin forms of dirofilariasis are treated with low doses of macrolides. The duration of therapy is from 8–9 months to 2–3 years, until adults are destroyed. In the presence of skin reactions, symptomatic treatment with specific drugs is prescribed.
During the treatment period, the dog must be isolated in a separate room or aviary. Only short walks are allowed, any physical activity of the animal is not allowed.
Disease prevention measures
It is very easy to infect dogs with dirofilariasis, therefore preventing it is quite difficult. In areas epidemiologically unfavorable for the spread of pathogens practiced treatment of animals with one of the following drugs:
- Ivermetin (Baymek, Ivomek, etc.),
These drugs belong to the group of macrolides and are similar in terms of safety for animals and at the same time, efficiency. Drug prophylaxis is possible from the age of 6-8 weeks. If the dog is 7 months old, before vaccination it is necessary to diagnose the presence of the disease in the body.
In the warm season, the dog is treated with repellents to protect against mosquitoes.
Additional measures are the treatment of animal skin repellents, the use of mosquito nets and fumigators in the premises. In the warm season, dogs are tested for the presence of the disease, since early detection of invasions eliminates pathological changes in the animal's body.
During periods of mass departure of mosquitoes should be limited to walking with an animal, especially near water bodies and in forests. After traveling with your pet to the areas of possible disease, it is advisable to visit the veterinary clinic and examine the dog.
Dirofilariasis foci develop near ponds and in basements. Therefore, medical structures are processing foci of the disease for the destruction of mosquitoes in them. To prevent mosquitoes from entering the apartment in the basement, the ventilation vents must be closed with a mosquito net.
Dirofilariasis in a dog is a dangerous infectious disease that requires timely diagnosis and treatment. If you recognize the symptoms in time and start the correct therapy, the disease is completely cured.
We offer to watch a video on which the veterinarian talks about dirofilariasis in dogs and other pets. Enjoy watching!
"Enemy" need to know in person
Dirofilarii use mosquitoes, as an intermediate "station" for their temporary residence. These viviparous worms in the course of their development pass through several stages. The whole danger lies in the fact that they tend to get into the blood vessels, heart and muscle tissue of the dog, where they can successfully multiply.
There are two types of these parasites:
- Heart-beating worms are usually females that can reach lengths of 30 cm or more, and 20 centimeters males,
- Subcutaneous worms (females - on average 15, males - 6 cm long).
Nematodes have a rather complex life cycle. The main "owner" of these parasites is a mosquito. Biting and sipping blood, for example, dogs, it swallows the larvae of these worms (microfilaria) with it, which then go through an additional development cycle inside the mosquito. Having matured, they need a new environment. Therefore, when such a mosquito again bites another dog, these mature larvae enter the blood through the blood. The animal falls ill.
IMPORTANT! Dogs are usually susceptible to infection with the nematode heart type. This is proven as a result of experimental research. In the course of it, all the animals that were bitten by a mosquito struck by their larvae fell ill with dirofilariasis. In the wild, these worms often infect wolves and jackals, which then form part of the reservoir hosts.
By the way, microfilariae without being in the blood of a mosquito do not pose any threat at all, in this form they can exist for 2 years without being fully aware of themselves. The blood of the insect is the medium for their maturation, which differs in different terms.
How does a dog infection
The ripening cycle depends on the air temperature: the warmer it is, the faster it goes. It is interesting that when the larvae cools off, without letting it know, they are waiting for warming. When the temperature comfortable for them appears again, the cycle continues again. All this usually lasts from 7 to 9 months. It is in the blood of his victim that dirofilariae end the period of ripening and begin reproduction, after which they move to the heart, where they settle.
Worms in the heart of dogs pose a great threat to their lives, because they affect their most important organs. It is quite clear that their long stay there is fraught with great harm that they cause to the health of the animal. In addition, the parasites in the heart of dogs contribute to the occurrence of adverse cardiopulmonary ailments, which is also not the best way affects the health of pets. Animals suffering from dirofilariasis suffer from shortness of breath, cannot move quickly, are dull, weak and sluggish, even though they are still young.
Worms that live in the heart and cause disease, round shape and white. Their larvae are called microfilariae, and adult worms are dirofilariae. The larvae usually develop in the blood of the animal and with it spread throughout the body.
If you do not start treatment in a timely manner, such a nuisance may arise. Drugs will destroy the worms, but what remains of them can contribute to the occurrence of thromboembolism. Worms in the heart of dogs always threaten their health. Launched malaise mostly ends with their death.
The skin form of dirofilariasis also creates certain problems for the animal. It usually suffers from dermatitis, itching, rashes. But this does not affect the internal organs at all and does not constitute any threat to the life of the dog. Considered helminths in the form of larvae and real worms are located in this case in the subcutaneous fatty tissue. But they are successfully removed surgically, and after a therapeutic course, which, with this ailment, is indicated after surgery, the disease goes away.
Symptoms in which dirofilariasis occurs in dogs
There are no specific signs indicating that this type of parasite is present in the body of a dog, if it is affected by heart worms. Symptoms of dirofilariasis in dogs in this case are characterized by their vagueness. Their intensity is affected by the type of damage and the time during which the worms are in the animal's body.
One of the first and most important symptoms of a dog affected by worms is the presence of a protein that is higher than normal, the so-called proteinuria. It develops because the dirofilaria larvae act on the kidneys of the animal.
With the skin form of the lesion, indisposition is limited to intolerable chesome, rash, inflammation in the place where the worms have found their refuge. The dog itches so much that it falls off shreds of wool, puffiness appears. The resulting infection can "hide" the place where the worms are located. Cardiopulmonary form can manifest symptoms such as:
- Expectoration of sputum with blood,
- Puffiness of paws,
- Unwillingness to eat,
- Fast fatiguability,
- Subfebrile temperature.
Some animals may have liver and kidney problems. But these parasites can concentrate not only in the heart and lungs. It happens when they are also found in the spinal cord, eyes and peritoneum.
Mostly noticeable symptoms of this pathology manifest themselves in the late stages of the disease. It is then that the dirofilaria larvae, having reached the adult stage, die. If there were many worms, their decay products contribute to the development of intoxication of the canine body.
During this period, the animal may experience:
- weight loss,
- accumulation of fluid in the abdominal cavity
- blue mucous
- weakness, even fainting,
- hoarseness, etc.
On what symptoms, the method of treatment depends. But it is still closely related to diagnostics. After all, only a properly established diagnosis allows you to pick up those medicines that will be effective for this particular case.
IMPORTANT! For more effective treatment, it is very important to keep a pet in a certain small room or aviary. It is also desirable to exclude exercise for the dog, because even running can affect the final result of the therapy. If the pet still needs fresh air, then very short walks are recommended.
Diagnosis of the disease
The qualitative definition of dirofilariasis in dogs is not so simple. False diagnostic results are not so rare. This is explained by many factors, including:
- infection has happened recently
- in the blood of the larvae predominantly males,
- when testing the animal rules were violated.
The test will not give the correct result, if the dog in front of him was given prophylactic drugs for dirofilariasis.
The main methods used to diagnose this pathology in an animal are:
- blood test,
- microscopic examination of blood smears for the presence of dirofilaria larvae,
- rapid investigation of the detection of these parasites,
- X-ray, ultrasound, which sometimes can determine the presence of worms in the heart.
Treatment of dirofilariasis in dogs is complex and expensive. But, most importantly, there is no complete guarantee of getting rid of this problem. Therefore, this process requires special monitoring by specialists. Without a veterinary clinic and its doctors can not do here.
Therapy of dirofilariasis involves the following areas:
- the death of adult worms and all their larvae,
- prevention of blood clots in the vessels
- maintenance of cardiac activity,
- prevention of possible complications.
IMPORTANT! A large dose of antihelminthic drugs can destroy parasites, but it can cause your pet to have a strong side effect of intoxication.
If dirofilariasis in skin-type dogs, then surgical removal of the adult dirofilaria is used. The damaged areas of the skin are treated with a solution of Imidacloprid 10% and Moxidectin 2.5%. Usually the results of such actions are not bad. So, only a single application of the solution destroys microfilariae. As for the treatment of animals in which the cardiopulmonary form of the disease, it is much more difficult. The microfilariae are then destroyed by Levamisole or Ivermectin. Usually this is enough for the lichinous stage of the disease.
There are cases when these drugs are used to destroy mature worms, when they threaten the health of an exhausted animal. But, if you simultaneously kill all adult worms, what remains of them can provoke a deterioration in the dog's well-being. Always determine the treatment and the necessary medication, eliminating the problem, should be a competent specialist who has some experience. Indeed, in the composition of drugs are present toxic arsenic compounds.
Dirofilaria drugs in dogs
Of the most applicable drugs should be noted Immititsid. The tool is effective in the destruction of adult worms. But it is contraindicated in animals with diseases of the kidneys, liver, heart and lungs. In this case, Ivermectin is used to treat.
Getting rid of helminths is only the first stage in the treatment of this complex ailment. Usually dogs are very weak and require recuperation. In addition, the internal areas of the body affected by this scourge require certain therapy. Therefore, based on the specific case, each dog develops its own therapeutic plan in accordance with the type of disease and its severity. Owners of dogs need patience, because the treatment can last a long time and be difficult.
It is regrettable, but it happens that with the running form of the disease the dog cannot be saved. This is especially observed when nematodes affect the heart and lungs. Owners of dogs should understand that the situation with the defeat of dogs by nematodes of this type does not allow frivolous attitude to it. Hope for their own knowledge and loss of time is fraught with the death of a pet.
Can the boss get sick?
This question often worries dog owners. We should immediately make a reservation, because the worms larvae transmit mosquitoes, dogs cannot be carriers of the disease, and they cannot be infected. Once people could pick up this ailment, having been in points with a humid and hot climate. It is there that there are usually many mosquitoes. But insects that are carriers of this dangerous disease, now, unfortunately, can be found in areas with a temperate climate.
IMPORTANT! For the health of the owner no threat to the sick animal. Feel free to care for your pet. A person can get infected with dirofilaria from mosquitoes that are carriers of their larvae. In this case, it usually affects the subcutaneous form of indisposition.
Dirofilariasis in dogs is a dangerous disease. This should always be remembered by those who want not to lose their pet.
Prognosis and prevention
In order not to happen to your pet like this, you need to seriously consider preventive measures. In this regard, you should try to keep the dog out of contact with mosquitoes, which are the main carriers of the considered parasites. It is necessary to ensure that it is not located in the places of their accumulation, and for prevention it is necessary to constantly influence its wool with protective agents against these insects, as well as ticks, fleas, lashes, etc.
Some owners, before going out with the dog for a walk, always treat his wool with mosquito spray, which they themselves use. And do the right thing. Who knows what can happen during a walk or a trip with a pet to nature.
It also does not hurt to constantly use drugs such as “Lawyer,” which allow the destruction of nematodes in the stage of microfilariae. Another medication for the dirofilaria called “IN-AP complex” was put on sale. It should be applied to the skin of the animal at the beginning of the summer, and then repeat the treatment every 6-7 weeks. The tool is well absorbed into the blood and, once there, destroys the larvae of heart worms.
It is not excluded that many who have encountered this pathology in a pet ask themselves questions: is it possible to completely cure dirofilariasis, is there any point in wasting money on such expensive treatment and tormenting oneself, as well as torturing an animal? Such doubts are well founded.
The prognosis for this disease is always positive with timely treatment for veterinary care and correct diagnosis. In this case, do not feel sorry for the means and efforts to put the pet on its feet. After all, this animal is often for many - a full member of the family. И возвращение его к нормальной жизни будет подарком не только для него, но и его хозяина, которому за заботу он ответит еще большей любовью и преданностью. Будьте всегда внимательны к своему четверолапому другу, и тогда никакие хвори, в том числе и дирофиляриоз, ему нее страшны.
Самки D. Immitis (heartworms) are usually 23 -310 mm, males - 120-190 mm long.
The body length of females D. Repens usually reaches 100-170 mm in length. Males are shorter - about 50-70 mm. Adult parasites can live for 5–10 years.
Adult worms Dirofilaria repens under the dog's skin (photo A) and Dirofilaria immitis in the heart (photo B)
After mating in the dog's body, the female worm releases the larvae, known as microfilariae. They can circulate in the blood up to two years.
When a mosquito of the genus Culex or Anopheles feeds on the blood of an infected animal, it becomes infected. These insects are natural intermediate hosts of the parasite. In the body of a mosquito, a certain period of maturation of the helminth to the third larval stage occurs, after which the larvae become infectious for animals and migrate to the salivary glands of the insect. Feline and canine representatives become infected during an insect bite.
The duration of gestation of the larvae inside the mosquito to the invasive stage depends on environmental conditions. For example, at a temperature of 30 ° C, this process takes from 8 days to 18 ° C - about a month. Below 14 ° C, the development stops and resumes as the temperature rises. This means that transmission of the disease occurs only in the warm season.
In the dog's body, it takes from 6 to 7 months for the worms to go through the last two molts, fully matured and begin to multiply.
Dirofilariasis in dogs occurs in many countries with a temperate climate. Heart chaps are especially common in the USA, Canada and Southern Europe. But also cases of the disease are recorded in Australia, Africa, the Middle East, India, Indonesia, Brazil. The causative agents of the skin form of the disease are most common in Mediterranean countries, especially Italy.
When D. Immitis acts as the causative agent of dirofilariasis in a dog, the cardiovascular system is affected. With the defeat of the animal D. Repens, the adult parasite moves under the skin. The severity of symptoms of dirofilariasis and the speed of their manifestation depend on the number of worms, especially if the heart is damaged.
Parasitism in the vessels leads to their mechanical damage. Often, worms clog the arteries, which causes pulmonary hypertension (increased pressure in the pulmonary arteries). The permeability of the pulmonary vessels increases, resulting in periarterial edema and alveolar infiltrates. In the end, the dog has irreversible interstitial fibrosis.
Symptoms of cardiac dirofilariasis are cough, shortness of breath, weight loss, general malaise, cardiac (swelling of the legs and inter-jaw space), and respiratory failure. In severe cases, the pulmonary vessels may rupture, leading to hemoptysis and nasal bleeding.
When the skin form of the disease is often asymptomatic. A clear sign may be a tumor-like formation under the skin. In the course of moving the worm outwardly noticeable, as this bump moves. Such formations cause itching, so you can observe how the dog constantly scratches the affected place. The dog's response to toxins is allergic reactions and dermatitis.
When the parasite settles in paraorbital tissue (ocular dirofilariasis) surrounding the eye, tearing and conjunctivitis occur.
The following diagnostic methods are used to determine dirofilariasis in dogs:
- blood test (filtration method, PCR) - microfilariae are determined,
- thoracic radiography (chest x-ray),
- echocardiography - in case of severe invasion, chronic pulmonary hypertension, right ventricular hypertrophy, flattening of the interventricular septum is determined, the worms can be visualized in the right heart and vena cava.
- ECG - manages to see right ventricular hypertrophy, severe pulmonary hypertension, signs of right-sided congestive heart failure.
Special rapid tests for the detection of dirofilariasis, which are designed to diagnose animals even at home on the basis of blood taken from them, deserve special attention. Its principle of action is to react to a protein that females of parasites secrete. Any test performed during the first six months after infection may give false negative results, indicating a low level of circulating antigen during this period. A positive result indicates the presence of the disease, but does not provide complete information about the current infection. Thus, these tests used at home are useful only for excluding or confirming dirofilariasis. For a complete picture of the disease, the dog must be examined by a veterinarian. One test will cost more than 7 dollars.
Subcutaneous dirofilariasis is more easily diagnosed and can be identified by external signs. During the formations on the dog's skin, its owner refers to the veterinarian, who, after opening, extracts the sexually mature worm.
Ocular dirofilariasis is determined by local symptoms. Sometimes you can see the worm itself, if it crawls close to the outer wall of the eyeball.
Heartworms can be detected in the right ventricle of the heart at the opening. So the diagnosis is established after the death of the dog.
The destruction of microfilariae (larvae) in the blood during dirofilariasis in dogs can be carried out using ivermectin, levamisole. These tools can also be applied in cases where the dog's body is so weak and damaged that it is not possible to kill adult worms. It is worth noting that drugs based on ivermectin are dangerous for breeds Colley, Sheltie, Doberman.
The most effective in cardiac dirofilariasis in dogs are arsenic compounds - melarsomina dihydrochloride, which has already replaced the outdated and more harmful sodium tiacetharsamide. He is able to kill adult worms. This drug is prescribed only after a full examination. In diseases of the kidneys, heart, liver and lungs, it is contraindicated and usually then ongoing supportive therapy is carried out using ivermectin.
Melarsomina dihydrochloride is available under the trade name Immiticide (Immiticide) and is an extremely expensive drug - worth hundreds of dollars.
After anthelmintic therapy, dogs require symptomatic treatment. Need to get rid of the effects of the disease. Animals with right-sided congestive heart failure need treatment with diuretics, ACE inhibitors. For severe symptoms, anti-inflammatory drugs, corticosteroids and antithrombotic drugs are administered. If there are serious malfunctions in the breathing process, oxygen masks are used.
Based on the articles presented on the website of the National Center for Biotechnology Information USA (NCBI), spot-on solution (for application to the skin) containing 10% of imidacloprid and 2.5% moxidectin is most often used for treating this form of the disease in dogs. As a result of a single use, it was possible to achieve a complete absence of microfilariae in the blood within 2 months after treatment and skin signs of the disease.
A solution of such a compound (imidacloprid + moxidectin) is sold under the trade name Advocate (Lawyer).
Sometimes surgical treatment is prescribed, which is necessary to remove the adult worm from the dog’s body. Two weeks after surgery, treatment with adulicides is carried out to finally get rid of parasites.
With timely identification of the disease, when it did not lead to serious complications, and successful treatment, the prognosis is favorable. Of particular danger are parasites of the species D. Immitis, which can cause significant and irreversible disturbances in the work of the cardiovascular system. In this case, not fatal.
The most effective method of preventing dirofilariasis is to limit the contact of the dog with mosquitoes. It is recommended to use insecticides for this purpose. Prevention is also carried out with the help of periodic use of anthelmintic drugs that can kill microfilariae. The first is a solution of imidacloprid and moxidectin (Advocate). It can have an effect on the larvae, until they have gone through the final stages of molting and have not managed to get through the bloodstream to the final habitats in the body. The dosage of medicines, as in the case of treatment, is prescribed by a veterinarian.