Many horses in Iceland have been going through an infectious upper respiratory disease for the last few weeks. The most common respiratory viruses have been ruled out by testing. The bacterium Streptococcus zooepidemicus has on the other hand been diagnosed in many horses with extended duration of symptoms. The disease has no relation to the recent volcanic eruption.
The infection has spread rapidly since the first cases were reported in early April. The disease manifests with symptoms from the upper respiratory tract, at first with serous nasal discharge, mild conjunctivitis and in many cases a dry cough. In some cases the nasal discharge turns mucopurulent. Temperature remains normal in majority of the cases, but tolerance to exercise is reduced. Morbidity is very high in horses kept inside, indicating that the horse population has none or very little immunity to the infectious agent. Incidence in horses fed outside is much lower and the symptoms milder. Mortality appears to be zero.
Horse owners are strongly encouraged to rest horses with symptoms and seek veterinary advice. The horses should be put on pasture as soon as possible and stables thoroughly cleaned. Special attention should be given to pregnant mares and mares with newborn foals and they kept on spacious pasture.
Infectious respiratory disease in horses in Iceland
