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Also Known As

Degenerative joint disease, Acute synovitis


Acute serous arthritis, also known as acute synovitis, is characterized by swollen, tender, fluid-filled joints. Although the joints are painful and swollen, this form of arthritis does not necessarily progress to degenerative joint disease.

Infectious (septic) arthritis is caused by bacteria in the blood stream invading the joints and attacking the cartilage, resulting in degeneration of the joints and cartilage.

Degenerative joint disease is a common arthritic problem in adult horses, usually resulting from injurious processes, such as bone spavin, osselets, or omarthritis, which leave the affected joint swollen, inflamed, and painful.


  • Swelling
  • Heat in the affected joint
  • Lameness
  • Stiffness and diminished range of motion


Arthritis in horses has several causes, including injury to joints, joint stress, bacterial infection, aging of the horse, and bone fractures. Acute serous arthritis is caused by either joint stress or injury.

Infectious (septic) arthritis is caused by bacteria from the bloodstream invading the joints and destroying cartilage.

Degenerative joint arthritis is the result of various processes that damage the joints and cartilage and cause bone deterioration, either as break-down of bony structures or as new bone growth that results in deformities to the structure.


Prompt attention to joint and bone injuries reduces the chances of arthritic complications developing later in the injured area. Early and appropriate care of injuries and wounds by a veterinarian can help mitigate soft tissue inflammation and pain as well as minimize any disintegration of bone and cartilage.

Cartilage thins as horses age, causing greater impact between bones as tendons and ligaments also lose elasticity. By taking this information into consideration when working older horses, damage, along with development of arthritis, may be minimized.

Shoeing by a competent farrier is another important part of preventing arthritis in horses. Proper shoeing, especially of horses with conformation problems, will help relieve stress on bones, joints, tendons, and ligaments, preventing or reducing damage to the structures.


Treatment of arthritis depends on the cause, the area affected, the extent of the injury or damage, and the age of the horse. Generally, acute serous arthritis is treated like a sprain, with rest, application of cold compresses, alternating temperature therapy, topical application of DMSO to reduce inflammation, and Butazolidin to help relieve pain and swelling.

After a flare-up and rest period, the horse should be slowly be returned to activity allowing the horse's system time to adjust to each increase in activity.

In the case of infectious arthritis, the diagnosis is confirmed by aspiration and analysis of joint fluid. Treatment should begin as early as possible with massive doses of antibiotics. In some cases, the veterinarian may suggest opening the joint to remove pus and debris. Butazolidin should be given to relieve pain and swelling. Stall rest and physical therapy are important for a successful outcome.

Degenerative joint arthritis takes many forms and treatment depends on where and how extensive the damage is. A veterinarian will want to see the horse in action, usually trotting in a straight line and in circles on a hard surface, to help determine the extent of the problem and to look for other complications.

Generally, all stressful activities that contribute to the arthritis and lameness should be discontinued. Use of nonsteroidal anti-inflammatory drugs, with hyaluronic acid injections into the joint, are beneficial. A veterinarian may make use of ultrasound, x-rays, and an arthroscopic examination to rule out other possible problems, such as fractures or bone fragments.

A farrier should check to make sure that the horse has proper shoeing to relieve stress on the joints. In some cases, fusing of joints, along with special attention paid to tendons, ligaments, and cartilage, will allow the horse to continue a productive life.

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EquiMed Staff

EquiMed staff writers team up to provide articles that require periodic updates based on evolving methods of equine healthcare. Compendia articles, core healthcare topics and more are written and updated as a group effort. Our review process includes an important veterinarian review, helping to assure the content is consistent with the latest understanding from a medical professional.