Diagnosis of equine arteritis virus infection in two horses by using monoclonal antibody immunoperoxidase histochemistry on skin biopsies.

The research article reports a case study of two horses diagnosed with equine arteritis virus infection using a novel method involving skin biopsies and monoclonal antibody immunoperoxidase histochemistry.

Overview of the Research

• The study revolves around two 5-year-old grade male horses exhibiting certain symptoms, including epiphora (watering of the eyes), rhinorrhea (runny nose), hyperemia in the conjunctival and nasal mucosal region (extensive blood flow), and a macropapular rash (small, combined flat and raised skin lesions) on the dorsal and thoracic areas.
• For diagnostic purposes, skin biopsies were obtained from the affected regions and subject to examination using a special staining technique involving a monoclonal antibody of the IgG2A subclass that targets a specific membrane protein of the equine arteritis virus (EAV).

Findings from the Biopsy

• On evaluation, identical results were found in both horses: mild to moderate superficial dermal edema (swelling of the skin due to fluid accumulation), vasculitis (inflammation of blood vessels), minimal perivascular lymphocytic infiltrates (immune cells around the blood vessels), occasional enlargement of endothelial cells (cells lining the blood vessels), and singular cell death (necrosis) observed in myocytes (muscular cells) of the tunica media (middle layer of the blood vessels).
• Upon immunohistochemical examination, certain endothelial cells, myocytes, and pericytes (cells surrounding the endothelial cells) were found containing intracytoplasmic EAV antigens, indicative of EAV infection.

Implications of the Findings

• The research concluded that immunoperoxidase histochemistry performed on skin biopsies could add value as a supplementary test in the clinical diagnosis of equine viral arteritis in horses, particularly when skin manifestations such as a macropapular rash is prominent.
• This method could potentially improve the accuracy and speed of diagnosing equine arteritis virus infection in horses, allowing for quicker and more effective treatment strategies.