Spat – an occupational disease in riding horses?

The horse's hock joint consists of several joint layers. The most mobile layer is the uppermost layer, where the lower leg and hock bone form a joint. The lower part of the joint consists of several rows of small bones that are held together by ligaments. There is little movement in this joint area. It serves more to absorb shock. These joints are therefore referred to as tight joints.

In the course of spavin, inflammatory changes occur within these tight joint rows. As the disease progresses, these changes lead to cartilage damage and the individual bones becoming fused together. The inflammatory process occurs in episodes, between which your horse is always lame-free and shows no signs of pain. Once the narrow joint spaces are completely ossified, the pain disappears completely. All that remains is the mechanical impairment caused by the stiffening of the joints. The bony growths are then partially visible or at least palpable from the outside. Depending on the severity of the disease, this process can take varying amounts of time.

Occasionally, changes also occur in the upper joint space. These are then referred to as high spavin.

A rather rare special form is the so-called osteolytic spavin. Here, the bones dissolve. This causes the joint spaces to become significantly wider.

As with most arthritic changes, there are many factors involved in the development of spavin. The primary cause is considered to be stress as an external, direct cause of the disease. This is the result of many small traumas to which the ankle joint is exposed during stress. Internal, indirect causes include positional abnormalities, angulation, and abnormal structure of the ankle joint, mineral deficiency, and hereditary predisposition.

Classic signs of spavin often develop gradually. The main symptoms of the disease are pain and lameness in one or both hind limbs. However, affected horses initially only begin to limp when under strain or at the start of work. The lameness is most noticeable when transitioning from a slow to a faster gait. In many cases, the lameness decreases during movement or even disappears completely. Due to the pain, the horse no longer lifts the affected limbs as high when walking. This causes the hoof tips to drag over the ground, resulting in a pronounced toe-in. When standing, the horse protects the affected limbs.

Another characteristic symptom is the appearance of more or less pronounced thickening, known as exostoses, on the inner surface of the hock joint. These bone growths are not painful, but do not occur in all horses with spavin.

Significant lameness is usually only noticeable when the disease is already advanced. However, the following signs may indicate creeping spavin even before lameness occurs:

• Clumsy gait
• Dragging hind legs
• Wear on the toe area of the hoof
• Decline in back and croup muscles
• Improvement in lameness when moving
• Stumbling
• Swelling and warmth in the hock area
• Lack of suppleness when riding
• Sluggish trot, shorter strides

The disease is not always easy to detect. If your horse shows signs of lameness, always have it examined by a veterinarian immediately to obtain a correct diagnosis.

Various examination methods are available to diagnose spavin with certainty. Your horse will be clinically examined and assessed while standing and in motion. Further examination includes a specific provocation test, also known as a spavin test. In this test, the hock joint is flexed for one minute and your horse is then immediately trotted forward. This makes it easier to assess whether the lameness has worsened as a result of the provocation. Another tool is diagnostic anesthesia. To narrow down the affected area, a local anesthetic is injected into the hock joint. The localized area can then be examined more closely using X-rays.

Due to its degenerative nature, the disease cannot be cured. Treatment aims to relieve pain and make life with spavin as bearable as possible. Depending on the severity and form of the disease, various treatment methods are available. In the early stages of the disease, anti-inflammatory and pain-relieving medication can be effective. In cases of osteolytic spavin, special medication is used to combat bone loss.

In cases of severe changes, arthrodesis (joint fusion) of the affected joint parts is recommended. This involves removing most of the joint cartilage by drilling into the joint space. This accelerates the stiffening of the joints. The necessary surgery is performed under general anesthesia.

Hoof care or shoeing is always an important part of treatment. Depending on the severity of the disease and the individual hoof position, your farrier will select a suitable orthopedic shoe in consultation with your veterinarian.

Alongside treatment, you can make a big difference to your horse's quality of life by optimizing its care and exercise routine. As with all other arthritic conditions, the saying "use it or lose it" applies! Horses with spavin need maximum freedom of movement. Because they are unable to bend their hind legs, or can only do so to a limited extent, standing up can be difficult. Affected horses need more space for this. Open stables with draft-free shelters or paddocks with a surface that is not too soft are recommended.

There are now countless feed supplements available on the market to support and optimize joint function in osteoarthritis. What can be used in individual cases depends on the severity and form of the spavin. It is advisable to discuss with your veterinarian which preparation is most suitable for your horse.

There is also a wide range of accompanying treatment methods. Symptoms can be improved using many different methods, from physiotherapy to laser treatment and osteopathy. Discuss with your veterinarian which method is best suited to your individual case.

In consultation with your veterinarian, your horse can still be ridden despite spavin. However, it is important to ensure a particularly long warm-up phase at a walk. Depending on the ground conditions, this can also be done outdoors. However, you should avoid riding on uneven ground, making tight turns, and sudden stops or changes of direction.

With treatment and proper management, you can still enjoy your horse for many years despite a diagnosis of spavin. Even horses that have undergone surgery can, for the most part, return to sports after sufficient recovery time.