Wolf teeth are vestigial teeth, which means that over the period of evolution they have lost their function so they are not actually necessary for the horse. They are usually quite small and are most commonly found in the upper jaw just in front of the first molar.
Research has shown that up to half of horses and ponies have wolf teeth, they start errupting at about six months of age and are fully visible by 12 to 18 months in horses that are going to have them.
Some wolf teeth fall out at about 3 years of age when the horse sheds the temporary second premolar.
Wolf teeth are not inherently painful to a horse but can interfere with the bit. As removal is not a major surgical procedure wolf teeth are often routinely removed.
Occasionally wolf teeth are present but do not erupt through the gum, they remain completely underneath the gingiva these are refered to as blind wolf teeth.
More on equine teeth - 10 signs your horse needs a dentist - recognising equine dental problems
Image: Malcolm Morley MRCVS