Seroprevalence of antibodies to Sarcocystis neurona in horses residing in a county of southeastern Pennsylvania

Abstract

Objective To determine seroprevalence of Sarcocystis neurona-specific antibodies in a population of horses residing in Chester County, Pa. Design Prevalence survey. Sample Population 117 serum samples from selected members of a population of 580 Thoroughbred horses. Procedure Serum was analyzed for antibodies to Sarcocystic neurona, using a western blot. Information regarding age, sex, and housing of horse was obtained by questionnaire. Data were analyzed, using multivariable logistic regression. Results Seroprevalence was 45.3% (95% CI, 36.3 to 54.3%). A relationship was not found between seroprevalence and sex of horse. Seroprevalence was greater in older horses (logistic regression; P = 0.16). Clinical Implications High seroprevalence of antibodies to S neurona and the lack of neurologic deficits among horses sampled indicate that positive results of serologic examination alone are of limited value for diagnosis of equine protozoal myeloencephalitis. Clinical signs consistent with the disease are the most important consideration in accurate diagnosis. (J Am Vet Med Assoc 1997;210:517–518)