This is no horn

This is no horn
This is no horn
Courtesy SMM
Unusual genetic variations can sometimes cause goats to grow more than the normal two horns.
Unusual genetic variations can sometimes cause goats to grow more than the normal two horns.
Courtesy Sean Munson via flickr.com

Different varieties of domesticated goats have different types and arrangements of horns; some are short and straight; some are long and spiraled. Most goats have just two horns, of course, but genetic abnormalities can cause individuals to grow as many as eight horns, or to have no horns at all. Usually only male goats have horns, but there are breeds where both male and female goats are horned.

What this goat has, however, is no horn. What it is… is a little difficult to figure out. Some features of the knobby growth on top of this skull make it look like a bone tumor, or osteoma. Like tumors in other parts of the body, bone tumors are caused by the abnormal growth of cells accumulating into a lump. Most bone tumors, however, are benign; they don’t spread and cause harm to the rest of body. People often get osteomas too, and while they can sometimes look a little unusual, they don’t cause any trouble unless they grow in a spot that can obstruct breathing, vision, or hearing.

However, doctor of veterinary medicine Bruce Oscarson points out that ruminants (the group of cud-chewing mammals that includes goats) don’t often get tumors, and a bone tumor in this location would be particularly unusual. Another possibility, suggests Oscarson, is that the growth is the result of abnormal healing of skull trauma. The animal could have gotten stuck by barbed wire, a person might have struck it, or it might have engaged in some overly enthusiastic head-butting. Even hornless males and female goats will engage in head-butting, and repeated blows to the head—with no horns to protect it—could have caused the goat to build up this a bony lump.