Another popular question at the barn - how bad are horse bites? Do people put down horses that bite people?
Horses are more inclined to bite than dogs, but horse bites are generally less serious. Only about half of horses have canines and when they do, they're vestigial. If a horse nails you, it's with grass cutting incisors. They seldom break the skin. Serious bites generally involve children who may have limbs small enough to fit entirely inside a horse's mouth, and horses have been known to sever fingers. For the most part, though, if a horse bites you it leaves a nasty bruise - sometimes a very nasty one. I once had a bruise from a horse take nine months to fade.
Pretty much everyone who rides and works with horses will get bitten. You learn to predict when a horse is going to nip at you and to dodge, but they can still get you. It's considered a normal hazard of dealing with the animals.
In some cases, modern liability laws may cause problems. If the public can get near your horses it's best to put up signs warning that horses can bite if fed or petted, sometimes by accident.
But overall, being bitten by a horse is painful and unpleasant, but not serious. However, anyone who rides should keep their tetanus vaccinations up to date - the bacteria tends to hang around stables. (If writing stories in the past bear in mind that lockjaw is a hazard for riders and horses and hard to treat without modern antibiotics.