Cause of Icelandic Horse Disease Found

A respiratory illness that caused nasal discharge and coughing in nearly 40,000 Icelandic horses in 2010 has been linked to a strain of Strepotococcus zooepidemicus.

The organism, which is closely related to the microbe that causes strangles infections, is commonly found on the skin and in the respiratory tract of horses and occasionally causes significant disease.

Researchers originally looked for a viral cause of the epidemic, but no virus was found in affected horses. However, most of the tested equines were carrying S. zooepidemicus, leading investigators to pinpoint the bacterial strain as the cause.