Eosinophilic Granulomas in Horses

Small lumps under a horse’s skin can be caused by several things, and might or might not be signs of a serious problem. One of the most common types of bump is about the size of a slightly flattened marble and is usually found on a horse’s back, neck, or withers. This is an eosinophilic granuloma which can easily be seen and felt below the skin although there is no abnormality on the skin’s surface.

Most eosinophilic granulomas don’t cause a problem and are not uncomfortable for the horse unless they are in a position to be rubbed or irritated by tack or blankets. A veterinarian can diagnose skin bumps and prescribe treatment if necessary. Many types are harmless and require no treatment.