Diseases Potentially Spread from Horses to Humans Via Bites Reviewed

The long list of diseases that humans could potentially contract after being bitten by a horse gives new meaning to the old adage, "Don't look a gift horse in the mouth."

According to the report, "That Horse Bit Me: Zoonotic Infections of Equines to Consider After Exposure Through the Bite or the Oral/Nasal Secretions," more than 100,000 emergency room visits per year are due to injuries from horses, and an estimated 3% to 4.5% of these visits are related to bites.

"In addition to the blunt trauma, breaks in skin, lacerations with tissue loss, and amputation of digits and noses, there are multiple bacterial and viral pathogens (disease-causing organisms) that can spread from horses to humans through biting," explained study co-author Rick Langley, MD, MPH from the North Carolina Department of Health and Human Services, Occupational and Environmental Epidemiology Branch in Raleigh, N.C.

A few diseases with the potential to be transmitted from horses to humans::

  • Rhodococcus equi;
  • Staphylococcus (including methicillin-resistant Staphylococcus aureus);
  • Hendra virus; and
  • Vesicular stomatitis virus.

Subsequent to a comprehensive review of literature, the study authors concluded that the equine foamy virus--an apparently non-pathogenic retrovirus--can potentially be transmitted through a bite.

Further, no reports of a human case of rabies due to a horse bite in the United States were identified; however, according to Langley, "It is theoretically possible and many persons are given PEP (post-exposure prophylaxis) to prevent a case.

"Considering that millions of people in North America are in contact with horses, it is important to be aware that equine bites are a public health event and that humans are at-risk for becoming infected with some unusual zoonotic pathogens that adversely impact the patient and community health," said Langley.

Langley's timely article comes in the wake of Hendra virus infections in Australia and the exposure of hundreds of people at a Texas rodeo to a rabid horse.  

But there really is no need to panic.

"Good personal hygiene, particularly hand washing with soap and water after any contact with horses, is an important step in minimizing the occurrence of these infections in humans," highlighted Langley.

Langley's review was published in a 2009 edition of the Journal of Agromedicine. The abstract is available on PubMed.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.