The international equestrian federation FEI reported an outbreak of the rhinopneumonia virus at a competition in the Spanish city of Valencia last Monday. An outbreak of rhinopneumonia like the one in Valencia could also occur in the Netherlands. In the Netherlands, horses are regularly found positive for the equine herpes virus, the causative agent of rhinopneumonia.
Eefke Weesendorp, Head of Diagnostics and Crisis Organization at Wageningen Bioveterinary & Research (WBVR): “Preventing the spread of the equine herpes virus is crucial in averting an outbreak. Diagnostics plays an important role in this. Early detection is necessary to be able to isolate infected animals as soon as possible.”
Early stage testing
Because rhinopneumonia cannot be distinguished from equine influenza, equine viral arteritis or other respiratory infections based on the clinical signs of respiratory disease, a definitive diagnosis can only be made by virus isolation or PCR on nasal swabs and blood samples. These tests can be used at an early stage of the infection.
There are two types of equine herpes virus that are common. In the Netherlands, infection with type 4 (EHV-4) is widespread. EHV4 mainly causes flu-like symptoms. Infections with type 1 (EHV-1) occur worldwide in all countries with a significant equine industry. EHV1 can result in inflammation of the respiratory system, pneumonia, abortion, death immediately after birth or neurological symptoms in horses and donkeys.
The PCR test, which detects the virus, can distinguish EHV-1 (the causative agent of the outbreak in Spain) from EHV-4. In addition, WBVR can detect antibodies that indicate an infection.