Equine viral arteritis

The Equine arteritis (from Latin equus " horse " arteritis " inflammation of the arteries ", Equine Viral Arteritis also EVA) is a viral disease of horses.

Cause and occurrence

The pathogen is the Equine arteritis virus ( EAV) of the genus arterivirus (Family Arteriviridae ). It occurs worldwide and affects horses, donkeys and crossbreeds. In warm-blooded animals the virus is endemic.

Transmission

The virus is excreted in secretions from infected animals. Transmission is by direct and indirect contact. The virus is excreted via the semen of stallions and can be transferred to the mare during mating or artificial insemination. The most common route of infection in foals is via the respiratory tract as a droplet infection. For the epizootiology are all collections of horses, such as sales and equestrian events of importance.

Pathogenesis

After an infection of the respiratory tract, the virus in the macrophages of the lungs and then into the bronchial lymph nodes increased. With insertion of the scattering agent through the blood ( viremia ), the endothelial cells become infected, which results in a necrotic arteritis.

Clinic and Pathology

After infection, the animals can remain completely asymptomatic or show fever, fatigue, loss of appetite and nasal and ocular discharge. Affected animals often show edema of the hind legs and the scrotum. In some animals, a rash develops at different body sites. Fatal progressive forms with pulmonary edema and inflammation (interstitial pneumonia ) occur in foals. Mares miscarriages are common, with the outgoing fetuses are only autolytic, so they show except a partial dissolution no specific pathological signs.

Pathologically show edema, vascular congestion and hemorrhage in the subcutaneous tissue of the abdomen and limbs, as well as a necrotic arteritis.

Diagnosis

The diagnosis can not be sure from the clinical picture. For further investigation, nose and eye swabs, blood, serum, tissue of aborted fetuses and sperm can be used, from which the virus can be isolated. A rise in antibody titer is also regarded as conclusive. Serological testing a virus neutralization test is used.

Combat

A treatment of diseased animals is not possible. The protection via vaccination is, however, possible. Other control measures in herds are disease prophylactic manner in which quarantine of new and equestrian events returning horses. To cover only seronegative stallions should be used, mares are separated from other horses.