What are they?
Wolf teeth are the variably-sized 'extra' teeth that some horses have in their upper jaws just in front of the first large cheek tooth. They erupt at about 6 months of age and are regularly found in yearlings. Occurring in 100% of zebras (where they are huge) the prevalence in riding horses is around 40-60%. They are equally prevalent in male and female horses, and some horses have only one. Although very rare in the lower jaw they are occasionally seen.
Do they have a function?
Rather as splint bones represent vestigial digits, wolf teeth are vestigial teeth that are slowly disappearing as the horse evolves. Eohippus, the South American precursor of the modern horse, had seven small upper cheek teeth on each side and lived on soft succulent plants. Subsequent climatic changes with secondary changes in vegetation required the horse to exist on much coarser grasses. Consequently much larger teeth evolved and the number of upper teeth was reduced to six, with the first (seventh) tooth becoming much smaller and non-functional, or absent. This small tooth is the wolf tooth.
It is unknown how the rather inappropriate term 'wolf' tooth became applied to these teeth and unfortunately it leads to confusion as the large canine teeth (tushes) seen in male horses are sometimes mistakenly called wolf teeth.
What do they look like?
The shape and size vary enormously (see photo). Although normally wolf teeth erupt vertically downwards through the gum into the mouth, in some (called 'blind' wolf teeth) the tooth takes a more shallow-angled path and never comes through the gum. In these the bump in the gum overlying the tooth can be felt, usually further forward than normal.
Does my horse have them?
It is not difficult to find them. Place the palm of your hand on the horse’s nose with your thumb pointing downwards. Then gently introduce your thumb into the horse’s mouth in the gap between the canine teeth and the corner of the lip (where the bit normally sits). Pressing against the hard palate, move your thumb backwards towards the first cheek tooth, feeling for the small wolf tooth, or in the case of a blind one, an obvious hard bump.
Are they significant?
It has been stated that 'there is no such thing as a good wolf tooth'. When pressure is applied to a snaffle bit via the reins the soft tissues of the cheek are pressed inwards against the teeth, impinging exactly where a wolf tooth is situated and potentially causing discomfort. This discomfort may show when ridden as head tossing, reluctance to take a contact, pulling downwards on the reins to release the contact and generally being unhappy in its mouth.
Although sometimes it is hard to see how very small wolf teeth could cause this response, on countless occasions over the years owners have reported an improvement in their horse's acceptance of the bit when these have been removed.
In addition wolf teeth inhibit adequate creation of 'bit seats' on the first upper cheek teeth. In this procedure the leading edge of the first tooth is shortened and rounded by the vet to create space for the soft tissue of the cheeks when squeezed by the bit. The wolf tooth gets in the way when one is working on the first tooth.
Wolf teeth can be removed at any age, the younger the better. All youngsters should be checked before breaking and introduction of the bit begins so that we can remove any wolf teeth early and prevent the development of bad habits.
How are they removed?
The horse is first sedated with a combination of a sedative and a painkiller. The tooth sits in a socket in the bone of the upper jaw, held in place by a dense ligament. Removal requires cutting of this ligament using a special instrument known as an elevator, and when loose the tooth is extracted with forceps. There is usually a tiny amount of bleeding but otherwise no adverse effects. The extraction site heals quickly and needs no further attention, although depending on the size of the tooth I like to avoid placing a bit in the horse's mouth for 5-10 days. During this time the horse can be lunged, ridden in a hackamore or long reined from a headcollar or cavesson if work must continue. If the horse is unvaccinated an anti-tetanus injection is given at the time of extraction.
In older horses the tooth may be virtually fused with the bone and sometimes it is not possible to remove it without fracturing it. This is rarely problematic because as long as the residual fragment is both stable and deep in the socket, the gum will heal over the extraction site and no long term effects will ensue. Not uncommonly in x-raying horse's heads for other reasons small wolf tooth fragments are seen sitting there and not causing a problem. Occasionally the scar tissue overlying the fragment will retract exposing the fragment and it can then be removed if required.
The legal situation
At present only veterinary surgeons are legally permitted to remove wolf teeth.
Removal of wolf teeth by non-vets, along with the possession and use of sedative
drugs, is illegal and consequently any insurance you or the 'operator' may
possess is null and void should any adverse events occur.
DISCLAIMER
This factsheet is intended for use by registered clients of EqWest only. The advice offered is general advice only. EqWest clients who wish to discuss the individual circumstances of their horse should contact the Clinic.
To speak to a vet please phone between 8.30 - 9.30 am on weekday mornings.
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