Lung Disease in Horses May Be Related to EHV

A recently discovered and rare lung disorder in horses may have some relationship to a more common disease that’s been known for years. Equine multinodular pulmonary fibrosis (EMPF) is the not the same thing as equine herpesvirus (EHV), and neither disease causes the other one. However, a study by German veterinarians showed that there may be some common factors between the maladies.

First described less than ten years ago, EMPF causes scarring in the alveoli (tiny air sacs in the lungs) where incoming oxygen moves into the capillaries and carbon dioxide, a waste product, leaves the bloodstream. The thickened nodules of scar tissue inhibit the ease with which this transfer takes place, leaving affected horses low in energy and struggling to breathe. Early signs can be mistaken for a bacterial respiratory infection, but antibiotics have no effect. As the disease progresses, horses have increased trouble breathing, begin to lose weight, and may die.

EHV has several types designated as 1 through 5. Effects on horses vary from none to serious, depending on the type of virus. In the group of seven horses tested in the German study, all equines infected with EMPF were also positive for EHV-5, and two were also positive for EHV-2. More research with a larger number of horses may reveal whether there is a definite relationship between the two diseases, and what that relationship may involve.