What is Bone Spavin?
A disorder of the lower hock joints, bone spavins are outgrowths of bone that interfere with the range of motion in the hind legs and can induce lameness and pain. Usually accompanied by osteoarthritis, this disorder can be a result of poor conformation or overwork, particularly if the horse is frequently overexerted while it is still growing. Although bone spavins are not curable, most horses that are afflicted are able to live productive lives, although the intensity of the workload may need to be restricted, depending on the type of activity and the overall condition of the horse.
A bone spavin is an overgrowth of bone in the lower hock joints that can cause severe pain as well as interfering with the range of motion in the hind legs.
Book First Walk Free!
Symptoms of Bone Spavin in Horses
The symptoms of a bone spavin tend to become noticeable gradually, although this can still vary from horse to horse. Signs of stiffness and lameness tend to be worse during exercise and ease when the horse is still.
- Dragging of hind leg or legs
- Hindlimb stiffness
- Poor performance
- Progressive hindlimb lameness
- Refusal to jump
- Uneven hoof wear
- Unusual stride
A bone spavin is an overgrowth of bone that develops in the lower hock joint. Several types of bone spavin can affect your horse.
- High spavin - A spavin that is found higher in the joint than most
- Jack spavin - This is an unusually large bone spavin that is found on the inside of the hock
- Juvenile spavin - These are spavins in horses that are under three years old; unlike adult forms of spavin, this is usually caused by diseases and congenital disorders, such as osteochondrosis or cuboidal bone distortion
- Occult (blind) spavin - A spavin that is found deep within the hock joint, where it can’t be either seen or felt, is referred to as a blind spavin or occult spavin
Causes of Bone Spavin in Horses
The cause of bone spavins in equines are numerous and not fully understood, despite its prevalence. Several conditions may increase the likelihood of bone spavins developing
Conformational defects that affect the lower hind legs, such tarsus valgus and sickle-hocks, can lead to bone spavins. Poor trimming or shoeing can force the equine feet into an unnatural conformation, leading to bone spavins in horses with good natural conformation.
A higher than normal ratio of affected animals in certain breeds, such as Icelandic ponies, indicates a possible genetic link to this disease.
A developmental disorder that affects the joints of growing animals, particularly animals with a high rate of growth.
Certain activities lead to excessive flexing of the hock joints or concussive force to them, which can encourage the formation of bone spavins. Dressage, show jumping, hunting, and racing all place high stress on the hocks, and care should be taken to allow for the joints to rest to avoid the formation of bone spavins.
Diagnosis of Bone Spavin in Horses
If your horse is exhibiting lameness like you would see with a bone spavin, your veterinarian is going to start the visit by performing a full physical. This will allow them to check for wounds to the hind feet or legs, cracks in the hooves, or sprains or strains that can have an effect on the hindquarters. A hindlimb flexion test, in which the hock is held in a forced flexion position for 30 to 60 seconds before trotting the horse, is often suggestive of bone spavin, although it is a supportive test rather than a diagnostic one.
Intra-articular local anesthesia is often introduced to the joint to definitively confirm the presence of pain coming from the joint itself, however, it is not able to clarify the cause of the pain. The initial diagnosis is usually substantiated by more advanced imaging techniques for the skeletal system, such as radiography or scintigraphy, which can differentiate this disorder from other disorders such as hairline fractures, osteosarcomas, or bog spavins.
Treatment of Bone Spavin in Horses
Although bone spavins are not curable, there are several types of treatment methods that can be utilized to ease the pain and maintain as much mobility as possible. Horses that are in competitive careers may be forced to retire, but most can be employed as pleasure and trail riding horses, and daily exercise is an important part of any bone spavin treatment plan.
- Shoes - Shoes with wedges, squared or rolled toes or even egg bar shoes, can help reduce pain and slow the degeneration of the bone in the hock area
- Pain medication - NSAIDs are very useful in managing both the pain and inflammation that are present with this disorder
- Injection - Injections of corticosteroids can alleviate mild lameness, sometimes for several months at a time; tiludronic acid, which is administered intravenously has also been proven helpful for reducing the symptoms of lameness
- Surgical remedies - In severe cases, surgical treatments may be used, including removal of the cartilage and the fusion of the joints that are affected by the spavins
Recovery of Bone Spavin in Horses
Bone spavin is a disorder that cannot be cured once it develops, but in some cases, it can be prevented. Steps that you can take that can help to avoid bone spavin from developing in your horse include:
- Allow an appropriate amount of time for joints to heal between vigorous workouts
- Don’t overwork growing horses
- Don’t use a horse with poor hock conformation in sports and activities that result in a significant amount of stress on the joints
- Ensure a proper fit to horseshoes
- Ensure that your horse gets enough exercise
- Provide suitable quantities of vitamins and minerals in the horse’s diet
- Treat damage to the hock speedily