Cutaneous vasculitis in horses: 19 cases (1978-1985).

The research article focuses on a clinical study of 19 horses diagnosed with cutaneous vasculitis, primarily presenting subcutaneous edema. Most affected horses were mares aged 3-10 years. Significant lab findings included neutrophilia. Most of the horses showed signs of leukocytoclastic vasculitis from skin biopsy specimens. The overall survival rate was around 63.1%, with 5 out of the 7 horses that died not responding to treatment. Fever was a significant predictive factor of poor prognosis.

Study Sample and Age Distribution

• The study reviewed the medical records of 19 horses with cutaneous vasculitis. This sample provided a snapshot of the condition across a range of cases.
• The age distribution showed a higher incidence of vasculitis in younger horses, with approximately 74% of the cases occurring in horses aged between 3-10 years. This could suggest a higher vulnerability of this age group to the disease.
• The study observed a significantly higher number of affected mares compared to stallions or geldings, noting this to be statistically significant (P<0.01).

Clinical Signs and Laboratory Findings

• The most common clinical sign was subcutaneous edema affecting the limbs, body, and/or head,
• Neutrophilia, a condition characterized by an elevated number of neutrophils, was the most prevalent laboratory abnormality. This was found in around 53% of the horses.
• From the skin biopsy specimens, around 86% of horses showed evidence of leukocytoclastic vasculitis, a condition that involves the inflammation and damage to blood vessel walls.

Treatment and Prognosis

• All horses in the study were treated with corticosteroids and supportive care. This highlighted the use of anti-inflammatory and immunosuppressive treatments for managing the condition.
• The survival rate was calculated to be around 63% with an average duration of corticosteroid treatment in survivors being around two weeks.
• Of the horses that failed to survive, most did not respond to treatment, and some were euthanatized due to persistent debilitating sequelae.
• The research found fever to be a significant clinical factor predictive of a poor prognosis, with a high odds ratio indicating the severity and seriousness of this symptom.

Underlying Causes and Potential Links

• Around 37% of the horses with cutaneous vasculitis had no history of bacterial or viral infections or current drug administration, suggesting other possible unidentified causes for the condition.
• Seven horses had a history of or exposure to horses with abscessed peripheral lymph nodes. This could indicate a potential link between these conditions and cutaneous vasculitis, and in particular, equine purpura hemorrhagica, a hemorrhagic disorder in horses.