The Many Faces of Arthritis in Horses

  

Update on Joint Injections: Joint Injections/A Good Idea?

New: "...In summary, joint injections are indicated in horses with OA that are expected to perform at their peak level with a high exercise volume. There is currently no cure for this condition. Current drugs approved to treat OA in horses prevent further progression and decrease clinical signs." Indications for Joint Injections

There are many types of arthritis in horses. Arthritis is a nonspecific term denoting inflammation of a joint. All joint diseases of large animals have an inflammatory component to varying degrees. Some examples of different types of arthritis are: Traumatic Arthritis-Traumatic arthritis includes traumatic synovitis and capsulitis, intra-articular chip fractures, ligament tears (sprains) involving peri articular and intra-articular, arthritis of the shoulder joint-inflammation of the structures of the shoulder joint is uncommon. It is secondary to changes in the joint capsule or, more frequently, to bony changes, septic arthritis-(Infective arthritis) Etiology and Epidemiology: Septic or infective arthritis results from sequestration of bacterial infection in a joint, viral arthritis (Revisal infection, Teensy), arthritis and encephalitis, septic arthritis-Infectious arthritis is most frequently associated with bacterial agents such as staphylococci, streptococci, and coliform's, immune-mediated arthritis (Inflammatory poly arthritis secondary to deposition of immune complexes can produce erosive destruction of articular cartilage and subcontract bone). It is my personal belief that not all of the types of arthritis, in horses, have been identified.

Osteoarthritis is one of the major problems of lameness in horses. You may hear it referred to as degenerative joint disease or DJD. At first you might notice that you horse feels "off" sometimes. He might short step or show some reluctance to impel forward. It comes and goes. You call your vet to do an exam. The vet tells you that your horse has arthritis. As noted above, arthritis affects many parts of the horse's body: the joints, the front fetlocks, the coffin joints, the navicular bones in the front feet, the stifle, the spinal column and even the eyes may be impacted.

Understand Joints and How They Work
Joints are quite exquisite when you think about how they work.

• Bones fit closely together
• Both ends of the bones are cushioned
• Cushioning is a layer of cartilage
• Cartilage prevents bone on bone rubbing together
• Cartilage acts as a shock absorber
• Cartilage absorbs impact and limits concussion
• Cartilage provides a friction less surface
• Cartilage does not have its own blood supply
• Blood supply (nourishment) to the cartilage comes from the synovial fluid
• Damaged cartilage has trouble rejuvenating itself
• When bone rubs against bone grinding down of bone takes place
• There is uneven wearing which causes pain
• Joints have a protective outer capsule
• It is fibrous in nature
• Inside that capsule is a synovial membrane
• Collateral ligaments connect the bones
• They provide protection and stability

• Consists of hyaluronic acid
• Hyaluronic acid is comprised of large molecules
• This hyaluronic acid helps to prevent inflammation
• Damage allows the invasion of white blood cells into the joint space
• This causes inflammation
• The joint's cartilage is damaged
• Released enzymes break down the hyaluronic acid molecules
• Chain reaction causes the synovial fluid to lose texture
• Cushioning and nourishment are reduced
• It manifests itself with swelling, heat, lameness
• Joint damage progresses to arthritis

At the present time there is no cure for arthritis. It can be managed with pain medication and anti-inflammatories. Eventually the horse will have difficulty working even with management attempts. At this point decisions have to be made as to how to proceed. This decision is one only the owner can make.

• Developmental Orthopedic Disease (DOD)
• Laminitis
• Navicular
• Coffin bone rotation
• Ringbone and Sidebone
• Tendon, ligament and soft-tissue damage
• Hock
• Stifle
• Horse Bone Spurs