While joint wear is an unavoidable process, management and vigilance can make a huge difference. Ensuring lots of low intensity, gentle exercise will help keep your dog free moving while minimising concussive force. Preventing obesity and ensuring a healthy, light weight will reduce force, oxidative stress and systemic inflammation. In addition to ensuring a balanced diet, nutritional supplements can help to support the maintenance and repair of joint surfaces. If your dog’s quality of life is being compromised, your vet may prescribe anti-inflammatory and analgesic medication.
The joint is very well structured to absorb impact and allow movement, but ultimately problems will start to emerge.
As the dog moves the areas of protective articular cartilage are put under pressure and can rub together. Over time this starts to degrade the cartilage, compromising its function and causing inflammation. In severe cases the cartilage can wear so thin that the bone rubs together.
Inflammation is a key component of joint disease that is associated with stiffness, pain and further damage. Damage to tissue results in inflammation, a response which is designed to protect tissue in the immediate, but tends to persist and becomes harmful. As well as directly restricting movement and causing pain, inflammation leads to oxidative stress which causes further damage to the joint tissue. It also reduces the integrity of the synovial fluid, thus reducing its protective ability.
Injury or infection can also result in joint problems by causing direct damage to the joint surfaces and/or the ligaments around the joint. When these ligaments lose strength the joint is less stable meaning that the forces are transferred through the joint unevenly. Similarly, poor confirmation will result in the excessive and uneven loading of certain areas of the joints.
Many dogs are prone to joint problems either from age, injury, conformation (either faults or breed specific confirmation), malnutrition in previously ill-treated dogs, or simply as a result of an active working life.
Early signs of joint wear are easy to miss. It may just be a slight stiffness when first getting up after a rest or reduced activity in general. Over time the joints will become more worn and painful, reducing the range of movement and resulting in more obvious lameness.
Although general wear and arthritic changes can occur in any joint on the skeleton, the problem areas are typically the lower limb and hock, where a number of small bones meet in areas that have to withstand large amounts of concussive force. Certain breeds are also prone to problems associated with their confirmation, hip problems among German Shepherds for example.
Joint wear can be particularly hard to notice when it occurs in both limbs because movement will remain symmetrical, keep an eye out for any shortness of movement or reduced desire to work and be active.
A joint is an area where two bones meet and articulate to allow movement. The joint is encased in a fibrous joint capsule and supported by ligaments that give stability.
The bone ends are rounded smooth structures that are covered by articular cartilage. The cartilage provides cushioning and a smooth surface for movement.
There is a space between the two bone ends called the synovial cavity that is filled with synovial fluid. Synovial fluid is critical because it absorbs impact and lubricates the joint surfaces to allow ease of movement and prevent friction. Because there is an absence of blood vessels within the joint, Synovial fluid is also needed to allow the transport of nutrients to the joint cartilage.