Hepatozoonosis
The Hepatozoonosis is a by parasitic protozoa of the genus Hepatozoon caused disease in dogs. It is unspecific with fever, weight loss and pain in the lumbar region. Occasionally bloody diarrhea occurs. A complete cure is not possible, but the disease can be brought under control with antiprotozoal drugs . The most effective prevention is protection against ticks , the oral ingestion of which causes infection.
Pathogen and transmission
In Europe, Africa and Asia, hepatozoonosis is mainly caused by hepatozoon canis . The pathogen occurs in southern Europe, Africa and Asia, so that hepatozoonosis in Central Europe is primarily a "travel sickness" (" Mediterranean disease "). In the summer months, the brown dog tick can also occur in Central Europe, in heated rooms all year round, so that there is also a risk of infection here.
In America, hepatozoonosis is mainly caused by Hepatozoon americanum . The carrier is the Gulf Coast Tick ( Amblyomma maculatum ).
The pathogen is transmitted orally by the ticks eating, swallowing or biting. Dogs are particularly susceptible, but cats are also susceptible. Hepatozoa attack the white blood cells, especially the eosinophils and monocytes , as well as endothelial cells of the spleen, liver, muscles, lungs and bone marrow. The infection causes a purulent granulomatous inflammation in tissues . By the formation of immune complexes one can glomerulonephritis or amyloidosis arise.
The pathogen is detected less frequently in cats, and as a co-infection it causes symptoms similar to those in dogs.
Clinical picture
The incubation period is two to four weeks. The clinical picture is unspecific. Symptoms of a general infection are flare-ups, weight loss and swelling of the lymph nodes. The mucous membranes may appear pale due to anemia .
The penetration of the sporozoites into the intestinal mucosa can lead to bloody diarrhea and loss of appetite. With schizonts in the muscles, hypersensitivity occurs especially in the lumbar region, muscle inflammation , stiff gait and muscle wasting. In young dogs, a reaction from the bones other than the skull is common.
diagnosis
The diagnosis cannot be made clinically; travel to the Mediterranean in particular must be inquired about in advance.
The blood count shows neutrophilia with a shift to the left . The number of red blood cells decreases ( normocytic , normochromic anemia ). The activity of alkaline phosphatase is increased.
The gamonts can be detected in the blood smear using Giemsa staining . Histological evidence of the schizonts can be made using biopsies . Indirect detection using antibodies using immunohistochemistry (IFAT) has been available in Germany since 2008.
The differential diagnosis mainly come babesiosis , ehrlichiosis , leishmaniasis and immune diseases into consideration.
treatment
Complete elimination of the pathogen is not possible. Clinical cure can be achieved with a combination of imidocarb and doxycycline or with trimethoprim and sulfonamides . A combination of trimethoprim, sulfadiazine , pyrimethamine and clindamycin is effective against Hepatozoon americanum . Decoquinate reduces the risk of relapse and increases survival time.
Prophylaxis is primarily possible by preventing tick infestation. Mite repellent and -abtötende effects amitraz , fipronil , permethrin , propoxur and pyriprole that at spot-on ( spot-on have a protective effect of about four weeks). Fluralaner is given orally and protects for twelve weeks. Deltamethrin and Propoxur have a protective effect of about six months when used in the form of impregnated collars, Dimpylat four months.
literature
- Cornelia Heile and Eberhard Schein (eds.): Guideline for preventing the transmission of pathogens through blood-sucking vectors in dogs . BpT 2007
- Richard W. Nelson and C. Guillermo Couto (Eds.): Hepatotozoonosis . In: Small Animal Internal Medicine . Mosby 2003, pp. 1302-1303. ISBN 0-323-01724-X
