The seroprevalence of antibodies to Sarcocystis neurona in Michigan equids

M. G. Rossano, J. B. Kaneene, J. V. Marteniuk, B. D. Banks, H. C. Schott, L. S. Mansfield

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


A cross-sectional study of serum antibodies to Sarcocystis neurona (the etiologic agent of equine protozoal myeloencephalitis, EPM) was performed on Michigan equids. Our objectives were to determine the seroprevalence of antibodies to S. neurona in Michigan equids and to identify specific risk factors for seropositivity. A random, weighted sample of Michigan horse farms (stratified by the state's opossum (Didelphis virginiana) population and the number of equids on each operation) was selected. Ninety-eight equine-operation owners agreed to participate, and blood collection occurred from late March through October of 1997. Data regarding the 98 farms' feeding and management practices were collected, as well as descriptive data for each of the 1121 individual horses. Serum samples were tested for antibodies to S. neurona using a Western blot test. The true seroprevalence of antibodies specific to S. neurona was estimated to be 60%. Chi-square analysis showed that seroprevalence was lowest in the colder parts of the state that had the fewest opossums (P < 0.0001). In two multivariable logistic-regression analyses with random effects grouped by herd, age and exposure to pasture were associated with increased odds of seropositivity, and feeding of sweet feed (grains mixed with molasses) was associated with decreased odds of testing positive. No association was found between farm size, animal gender, hay types, horse-housing types or exposure to natural surface water and seropositivity.

Original languageEnglish
Pages (from-to)113-128
Number of pages16
JournalPreventive Veterinary Medicine
Issue number2
StatePublished - Jan 29 2001

Bibliographical note

Funding Information:
We thank RoseAnn Miller, Alice Murphy, Ruth Vrable and Barbara Knust for their expert technical assistance. We also thank Dr. John Shelle and Dr. Christine Corn for their participation in the EPM project. This research was funded by the Animal Health Initiative Grant, State of Michigan, 1996 and the Population Medicine Centre.


  • Equine protozoal myeloencephalitis
  • Horse
  • Opossum
  • Sarcocystis neurona
  • Western blot

ASJC Scopus subject areas

  • Food Animals
  • Animal Science and Zoology


Dive into the research topics of 'The seroprevalence of antibodies to Sarcocystis neurona in Michigan equids'. Together they form a unique fingerprint.

Cite this