Leishmaniasis in animals: symptoms, diagnosis and treatment
Leishmaniasis is an infectious animal disease caused by an intracellular parasite. This parasite of the genus Leishmania is carried by mosquitoes. The spread of the disease is promoted by both domestic and wild mammals. Leishmaniasis can be a visceral or dermal form.
The life cycle of the parasite passes with a change of hosts: a vertebrate animal, including a human, and a mosquito carrier. There are two types of leishmania - flagellum, parasitizing in the blood-sucking insects, and non-felid - in the cells of the host macrophages.
Leishmaniasis is spread in animals mainly endemically. Most of the cases are registered in developing countries. In 32 countries the disease is subject to mandatory registration.
For the first time leishmaniasis in an animal in Russia was discovered in 1909. The case described belonged to the dogs of Transcaucasia. From 2008 to 2010 in Ukraine, there were 52 cases of this disease in dogs.
The disease begins from infected animals or humans. Insects with bloodsucking receive amastigots, which begin active reproduction in its intestines. After 8-10 days amastigots pass into invasive forms, concentrated in the proboscis of the mosquito and the anterior parts of the intestine. At the next bite of the carrier, the parasite enters the blood of the vertebrate and begins to multiply. Just one day in a single cage there may be more than 200 pieces of astigot. The cells full of parasites are completely destroyed, amastigots are trapped by neighboring cells, in which the process is repeated. Thus, leishmanias appear in the skin, bone marrow, liver, lymph nodes and any other organs.
Depending on the form of the disease, the clinic can be different. The incubation period of visceral leishmaniasis can last up to 10 months, developing gradually.
Leishmaniasis of the skin develops rapidly, its incubation period is extremely short.
Disease affects animals of any age and sex. Young animals are less likely to develop symptoms at an early stage, leading to late diagnosis and a higher mortality rate. Some studies prove that animals aged 3-5 years are most susceptible to leishmaniasis.
Leishmaniasis in animals, a photo of which can be seen here, runs according to the classical scheme, affecting all the organs and cells of the animal.
The cutaneous form of leishmaniasis begins with the appearance of nodules at the site of the bite by the carrier. Over time, these nodules flow into ulcers. The places around the eyes, the back of the nose and the ears of the animal are most prone to primary disease.
In this form, the disease can take place sluggishly, for a year or even longer. The death of an animal at this stage is extremely rare. Visceral leishmaniasis is much more severe: it can be acute or chronic. With any form of fever, there is a general depressed state of the animal, a strong weight loss.
Simultaneously with the remaining signs, the diseased animal develops conjunctivitis, anemia, and digestion disorders are often observed. Paralysis or paresis may occur, hemodynamics is significantly impaired. As the organism slowly decays under the influence of parasites, allergic or toxic reactions are possible.
When the reproduction of leishmania increases, the liver, lymph nodes and spleen. The acute form of the disease is more typical for young animals. Usually, death occurs a few months after the appearance of the first signs of the disease. There are rare cases of recovery.
With the visceral form of leishmaniasis, the weakness of the animal's organism gradually increases, fatigue increases. Skin pale, appetite decreases. At this stage, by enlarging the spleen, you can see an increase in the spleen. There is a slight increase in temperature. If the temperature has increased significantly, it indicates the peak of the disease. This course of the disease can last up to 3 months.
When the disease develops, anemia, cachexia, can begin. On the mucous there are sites affected by necrosis. There may be heart disease.
Leishmaniasis in animals in the cutaneous form manifests itself within 10-20 days. Initially, a papule with a diameter of about 3 cm appears. After about 2 weeks, one can already observe a necrotic focus surrounded by a roller of infiltrated skin with abundant secretions. Near the primary leishmanoma, secondary tubercles are formed, turning into new ulcers. Over time, all ulcers merge into one large hearth. With proper and timely treatment, these ulcers heal in a few months, in their place remain significant scars, which are rarely covered again with wool. Bumps and ulcers are almost painless formations.
If the disease is long enough, the risk of developing nephritis, diathesis, pneumonia, agranulocytosis is high. There is a high probability of purulent-necrotic inflammation. With significant damage to the body, irreversible damage to the organs of vision is possible.
With leishmaniasis, various studies are conducted to identify the pathogen. Thus, a general blood test can show increased ESR, hypochromic anemia, low platelet count. Biochemistry will reveal hypergammaglobulinemia. Cutaneous leishmaniasis in animals is diagnosed after isolation of the pathogen from ulcers and tubercles. Visceral leishmania is detected in the blood culture. In some cases, a biopsy of various organs is performed.
In epidemiological studies, a skin test with leishmanin is performed (Montenegro reaction).
At the present time, new methods for diagnosing leishmaniasis are being developed, since those that are currently available require significant material costs and take a lot of time.
Ulcers in leishmaniasis are similar to foci with anthrax carbuncle, so for the precise diagnosis it is preferable to exclude the presence of an anthrax.
Leishmaniasis in an animal, passing in mild form, sometimes ends in an independent recovery. With timely diagnosis and proper medical intervention, the favorable end of the illness is also great. In severe conditions, with infection of individuals with weak immunity, in the absence of medication, the likelihood of a lethal outcome is high. Leishmaniasis of the skin always leaves scars or scars.
Leishmaniasis of animals is treated with preparations of pentavalent antimony. These drugs are of the type "Glucantima", "Solyusurmina" or "Neostibozan". With the visceral form of the disease, these drugs are administered intravenously for 7-10 days with a gradual increase in the recommended dose. If treatment is not effective, then connect "Amphotericin B", which is injected slowly intravenously in a complex with a glucose solution of 5%.
Cutaneous leishmaniasis in animals at an early stage is cured by cutting the tubercles "Monomycin", "Urotopin." In addition to injections, lotions are made with the same drugs. If ulcers are already formed, use the intramuscular means Miramistin. To speed up the process of tightening ulcers, the use of laser therapy is recommended.
Reserve funds for the disease are "Pentamidine" and "Amphotericin B", which are prescribed in cases of resistance of the parasite to traditional drugs or if the infection recurs.
In order to increase the effectiveness of treatment add recombinant gamma-interferon, developed for human treatment.
In rare cases, the removal of the spleen must be surgically removed.
Despite all the measures taken to get rid of the disease, even after full recovery of the animal, the causative agent of leishmaniasis from the body may not completely disappear.
At the moment there is no way to vaccinate animals and humans. To protect against phlebotemus bites, it is recommended to use special insecticides, created for use in veterinary medicine.
As a preventive measure of leishmaniasis in populated areas in the risk zone, the places of mosquitoes' settlement are eliminated, disinfestation of premises is carried out.
When detecting the disease in domestic mammals, it is customary for hosts to conduct chemoprophylaxis with "Pirimetamine".
When a disease is detected in wild animals, it is recommended that the destruction of these individuals with the complete elimination of their remains be recommended for prevention.
Attitude towards people
More than 350 million people are currently at risk of infection. The centers of the spread of leishmaniasis are found on the vast expanses of Asia and Europe. In different areas, the carriers of leishmaniasis are the blood-sucking insects that live there. Cases of visceral leishmaniasis are registered in Ukraine, North Ossetia, in the Crimean steppes, the Caucasus Mountains and some other regions.
The disease is not transmitted directly from the animal to humans, but when infecting the first, prevention is recommended for people, since the very fact of the disease speaks of the presence of its vectors.
Leishmaniasis - these are diseases that do not produce antibodies. Accordingly, an animal or a person can become ill the second time, and the third. However, such cases are extremely rare, since it is unlikely that the animal will be able to survive more than two repeated infections.
To prevent recurrence of the disease, the drugs recommended for treatment are applied every six months. However, such frequent use can lead to the development of the body's resistance and toxic effects.
After the transferred disease the animal body needs a long rehabilitation, and in the case of partial or complete removal of organs by surgical means, it is necessary to follow a diet.
Leishmaniasis in animals is an extremely dangerous and insidious disease; therefore, those who live in unfavorable areas should carefully monitor the animals so that when the first symptoms (or even just a suspicion of the disease) appear, they must provide the necessary assistance in time.