Infectious canine hepatitis
The hepatitis contagiosa canis ( Hcc; syn: " Infectious hepatitis of dogs," Rubarth disease, fox encephalitis, infectious canine hepatitis (ICH) ) is a caused by a virus hepatitis of dogs. Overall, the disease - now rarely observed - as a result of effective and comprehensive vaccination.
Epizootiology
The causative agent of Hcc, Canine adenovirus 1 (CAV -1), belongs to the family Adenoviridae, genus Mastadenovirus. The Hcc occurs worldwide and can besides most dogs and skunks, raccoons and some bear species affected, with a total domestic dogs have the highest susceptibility.
The virus is excreted in the acute illness through saliva, feces, nasal secretions and urine. After healing or latent virus carriers in particular the urine plays a role in disease transmission. Also, a transmission from the mother to the fetus via the placenta has been demonstrated. In most cases the infection occurs through contact with secretions unprotected animals clinically inapparent infected animals. Since the excitation is quite stable, it can outside the living organism at room temperature for several weeks up to 9 months remain infectious even at temperatures below 4 ° C. The germs get especially orally, ie through the mouth, into the host, where it first occurs with viral replication in the tonsils and lymph vessels and lymph nodes for distribution via the blood. This viremic phase lasts approximately 4 to 8 days. As a consequence, especially liver cells ( hepatocytes), the inner lining (endothelium ) of blood vessels, the endothelium of glomeruli and cornea ( cornea) and medium-sized eyeball ( Uvea) are affected.
The incubation period is 2-5 days.
Symptoms
The symptoms vary greatly depending on the waveform. In general it can be said that the prognosis is more unfavorable, the more acute the outcome is.
Peracute course
In the peracute course of the animals die within a few hours. The only symptom is usually finest bleeding ( petechiae ) due to a coagulopathy (DIC ).
Acute course
The acute course also begins with a high fever, lethargy, vomiting and loss of appetite. The tonsils, lymph nodes, spleen and liver are swollen. Due to the vascular inflammation occur edema and bleeding ( petechiae, ecchymosis ) of the mucous membranes as well as in the body cavities and the anterior chamber. Neurological symptoms are observed occasionally by bleeding into the central nervous system. In addition, kidney damage can occur due to deposition of immune complexes in the glomeruli, which are manifested by the appearance of protein in the urine ( proteinuria). The same cause have observed occasionally clouding of the cornea ( blue-eye syndrome, see below).
The Leberpalpation is painful in general.
Subacute course
The subacute begins as acute, the symptoms are less pronounced. Here dominate fever, diarrhea, vomiting, and uveitis. After 1-3 weeks occurs a bluish haze of the cornea as a result of edema and deposition of immune complexes ( blue-eye syndrome), which spontaneously heals usually 1 to 2 weeks later.
Chronic History
When chronic course, only minor symptoms. It is therefore recognized only rarely. Here, the organism is unable to eliminate the virus, so that there is a permanent colonization (persistence ) of the liver, and thus a chronic hepatitis leading to liver fibrosis and cirrhosis.
Diagnosis, differential diagnoses
In addition to the symptoms already described above, affected animals often have a low platelet count (thrombocytopenia) and an increase in the activity of liver enzymes. The clotting time may be extended significantly due to a consumptive coagulopathy. Many patients excrete proteins and bilirubin in the urine. A definitive diagnosis is possible or possible with the histological examination of liver biopsy on the isolation of virus material in the nasal secretions, blood or urine.
Distemper, parvovirus, leptospirosis and bacterial or caused by other viruses tonsillitis are the main differential diagnoses. The mucous membrane bleeding and sudden deaths can remember a poisoning with anticoagulants.
Therapy
A causal therapy is not possible. About the administration of specific immunoglobulins or interferon, a treatment attempt be made, the effect of which is, however, not proven. In addition, supportive measures within the meaning of symptomatic therapy are useful.
Prophylaxis
Best combination vaccines are used for the prophylaxis, the next Hcc immunize against distemper, parvovirus, leptospirosis, and rabies and are offered by a variety of manufacturers (eg versican DHPPi L3 R, EpiVax SHPPi LT, Eurican SHPLT, Nobivac SHP LT, Quantum DAPPi / CVL, Virbagen canis SHPPiLT ). The use of live vaccines may cause the occurrence of blue-eye syndrome here. Conveniently therefore, the use of inactivated vaccines or heterologously attenuated CAV -2- live vaccines which avoid this effect.