Nocardia asteroides infection in horses: a review.

The abstract discusses a study that explores the cases of Nocardia asteroides infection in horses documented from 1965 to 1983 at the Veterinary Medical Teaching Hospital, University of California, Davis. It found that horses with different levels of immunosuppression, including Arabian foals with combined immunodeficiency and aged horses with hyperadrenocorticism, were susceptible to such infections, often with fatal outcomes.

Summary of the Cases

• Over a span of 18 years, 16 cases of Nocardia asteroides infection were reported in horses at the given veterinary hospital.
• Out of these, two cases involved infections that were localized and caused by trauma. The horses affected by these cases recovered without the use of any significant antimicrobial therapy.

Pulmonary or Disseminated Infections

• Fourteen horses encountered pulmonary or disseminated infections that ultimately proved to be fatal.
• All these horses had varying degrees of immunosuppression, which possibly increased their disease susceptibility.

Disease Associations

• Among these cases, eight were Arabian foals suffering from combined immunodeficiency disease.
• Three cases involved older horses that had developed hyperadrenocorticism due to pituitary tumor that produced excessive amounts of Adrenocorticotropic hormone (ACTH).
• The remaining three cases included a horse with lymphosarcoma, another with liver disease presumed to come from a toxic source, and a final case involving a horse with a mixed disseminated bacterial infection.

Significance of the Investigation

• The findings indicate a strong correlation between immunosuppression and susceptibility to Nocardia asteroides infection in horses.
• The diversity of associated conditions, such as immunodeficiency, hyperadrenocorticism, lymphosarcoma, liver disease and mixed bacterial infection, suggests that this infection can potentially affect horses with a wide range of health issues.
• The study highlights the importance of early detection and effective treatment strategies for managing Nocardia asteroides infection in immunosuppressed horses.