Mary Allen
Warts on the horse’s head do not look pretty, but in most cases, they are only the symptom of harmless disease. However, a closer look is important. Skin tumors can also look like warts.
In papillomatosis, warts sprout like cauliflowers. They are about the size of a lentil, pink, white-yellowish, or grey, they can be flat but also slightly stalked. Foals and young horses up to three years of age are particularly affected, and the disease often breaks out in summer.
Horse warts grow primarily around the nostrils and lips, sometimes also on the head and in the auricles, rarely on the legs and genitals. Although they can also occur individually, they usually proliferate in groups and can expand greatly. In many cases, this not only looks ugly but also alarming. Fortunately, there is no real cause for concern.
«The affected horses appear completely unaffected, but they don’t look in the mirror either! The changes rarely start to itch, so that the horses scratch themselves,” says Anke Rüsbüldt, a veterinarian specializing in horses with her own practice near Hamburg and author of specialist books. Among other things, she wrote the guide “Skin diseases in horses: recognizing, preventing, treating”.
Horse warts can be surgically removed, but pigment spots remain. There is another reason why the procedure is extremely rare and only recommended for very annoying horse warts. The ugly knots heal by themselves. This usually takes about two to four months, sometimes longer. The horse is then immune to further outbreaks, for which the pathogen “Equine Papillomavirus Type 1” is probably responsible.
Early Treatment is Advisable
Even if real horse warts are harmless, you should consult your veterinarian if the horse has wart-like spots, lumps, or other skin abnormalities. Especially in the early stages, there is a risk of confusion with the equine sarcoid, a skin tumor triggered by the bovine papillomavirus of cattle. Insects are probably responsible for the spread of the virus, but the exact transmission routes have not yet been clarified. Whether a horse actually gets a skin tumor probably also depends on its genetic predisposition.
While the bovine papillomavirus causes harmless warts to grow in ruminants, it leads to a skin tumor in horses, which can appear in six different variations and on any part of the body. “This tumor grows invasively, which means it destroys the tissue into which it grows,” explains Rüsbüldt. “Sarcoids do not form metastases in internal organs and usually do not affect the affected horses at all at first.”
Nevertheless, the equine sarcoid should definitely be treated. This is because the main tumor usually grows quickly and aggressively. Depending on the position, it also makes it almost impossible to saddle or bridle. On the other hand, the earlier you treat the sarcoid, the greater the chance of getting rid of the skin tumor completely. “Unfortunately, the nasty tumors have a high tendency to recur: if you operate on them and cut them out completely, there is a high probability that such a tumor will grow again in the same place,” warns Rüsbüldt.
Depending on the individual case, the vet selects a therapeutic approach or a combination of various methods. You can choose from radiotherapy, cryosurgery and electrosurgery, laser, chemotherapy, and immunotherapy. For some time, acyclovir ointment, which was developed to combat herpes in humans, has also been increasingly used in treatment.