The phrase soundness or sound horse isn't referring to the creatures whinny it refers to the overall health of the animal. A sound horse is one that has no lameness or illness. When purchasing a horse, it's a good idea to have a veterinarian check the animals soundness.
What is Lameness?
Lameness is one of the most common health issues for horses as their legs can be quite delicate. A horse with lameness means they that have difficulty walking. There are degrees of lameness which range from difficult to observe to a complete inability to walk. While lameness can be a sign of trouble in the legs, it can also indicate issues in another part of the body. Many common horse ailments can cause lameness in horses. Severe lameness in a horse can even be fatal.
Vets will also examine the horse for any hereditary illnesses such as cataracts or bone spavin. These types of hereditary illnesses can limit a horse's usefulness when it comes to breeding and reproduction. However, these kinds of hereditary issues may matter less to someone in need of a workhorse as opposed to a breeder.
When is a Horse Considered Sound?
A horse that is sound is considered close to perfect which means few horses truly fit this description and if so will only fit it for a few years of life. This doesn't mean that a horse that's a little past its peak is no longer a good investment. A horse that is labeled as practically or serviceably sound is capable of regular work for the horses class but may have some health issues. It's important to understand the class of a horse before assessing soundness as what an owner requires from a sound racehorse will be inherently different from a field horse.
Checking Soundness at Home
While a trained veterinarian is the best person to assess the soundness of a horse, there are some warning signs you can look for that mean an educated opinion is necessary. Asymmetry in the face muscles can indicate a dental issue as can signs of teeth grinding. Having a limited range of motion in joints or signs of inflammation can be a sign that a horse may be unsound and should be checked by a vet. Cracks in the hoof wall and hoofs that do not land evenly are also signs that a vet should be called. While not every cause of lameness will be hereditary or untreatable, it's best to find out before making an expensive purchase.