I.Joint Anatomy

A joint is where two bones meet. There are many joints in the body. They can be classified according to how much movement can occur at the joint. The joints which allow the most motion, such as the elbow, knee, shoulder and hip are called synovial joints. A synovial joint consists of two bone ends that are held together by ligaments and a joint capsule. The two bone ends are covered with cartilage called articular cartilage. The joint capsule contains a small amount of fluid called synovial fluid. Synovial fluid is made by the synovial membrane, which covers the inside surface of the joint capsule.

The presence of joints allows arms and legs to move fairly freely. This movement causes forces to be applied to the joints. For example the force of its body weight coming down on the hip or knee as a dog runs. The joint capsule and ligaments help to distribute this force of movement evenly over the joint surface. Cartilage at the ends of the bones acts as a shock absorber, and synovial fluid lubricates the joints and provides nutrition to the cartilage.

An illustration of the normal joint

II.What is Arthritis

Arthritis is inflammation of the joint. The most common type of arthritis that dogs get is osteoarthritis or degenerative joint disease. This can occur as part of the aging process or in younger dogs that have abnormal joints (hip dysplasia). With osteoarthritis, changes to the articular cartilage cause inflammation. This inflammation causes further damage to the cartilage and the rest of the joint. More joint damage causes more inflammation until a vicious cycle of damage and inflammation is present. The joint damage and inflammation both cause pain. As arthritis gets worse, the articular cartilage is lost, the joint space between the two bones becomes smaller, and eventually, the bones rub together. This is extremely painful.

A joint with arthritis

III.What to Watch for at Home – Symptoms

The symptoms of osteoarthritis depend on how severely affected a dog is and what an individual dog’s pain tolerance is. They include

• Reluctance to move around


• Stiffness when moving around


• Stiffness that is present when first moving around but gets better as the dog moves more


• Increased stiffness or pain the day after strenuous activity


• Muscle atrophy from decreased use


• Unwillingness or inability to jump as far as previously able


• Limping


• Slow to get up after laying down


• For some dogs, decreased appetite when pain is bad


• Change in body position when urinating or defecating (for example, does not want to squat as far to urinate or defecate)


• Inability to bend or move joints as much as previously able


• Symptoms may be worse during cold or wet weather

Commonly affected joints in the dog are the hips, elbows, and knees although any joint can be affected. Osteoarthritis is most commonly seen in middle-aged and older dogs, but young dogs with hip or elbow dysplasia or other joint abnormalities may also develop osteoarthritis.

IV.The Veterinary Visit – How to Diagnose Arthritis

A large part of the diagnosis of osteoarthritis is based on the age of the dog, the history, and the physical examination. Often during the physical examination, pain and decreased ability to move joints is found. The diagnosis of osteoarthritis is confirmed with x-rays of the affected joint or joints.

V.Treatment

Osteoarthritis cannot be cured, but it can be treated. The goals of therapy are to reduce pain and to try and stop the inflammation-joint damage cycle. There are many different treatments available for osteoarthritis in dogs. A therapeutic plan should be tailored to each individual dog and owners needs. Do not give your dog any over-the-counter medication without taking to your veterinarian first. Many of these can be toxic to dogs. Some of the commonly used treatments include:

• Oral glucosamine and chondroitin supplements. Glucosamine and chondroitin are a normal part of the cartilage found on the ends of the bone. In people, there are some studies that show that taking these supplements helps to maintain a more normal joint space (space between the ends of the bones), slows the progression of osteoarthritis, and provides pain relief. There are some prescription diets available that are already supplemented with glucosamine and chondroitin.


• Omega-3 fatty acid supplements (fish oil). Fish oil contains two omega-3 fatty acids, EPA and DHA that are anti-inflammatory. In osteoarthritis, decreasing inflammation in the joint will help decrease pain and make a dog more comfortable. Oral capsules are available which contain fish oil and there are prescription diets available that contain EPA and DHA.


• Injectable glycosaminoglycans. Glycosaminoglycans are molecules which are a normal part of cartilage. Supplementing them may slow the progression of osteoarthritis and provide pain relief. The main advantage of these over oral glucosamine and chondroitin is that they are not given as often. The injections are given in the veterinarian’s office once or twice weekly for four to six weeks and then once monthly or as needed to help control symptoms.


• Oral NSAIDS. Non-steroidal anti-inflammatory agents (NSAIDS) help to decrease inflammation and reduce pain. There are many available for use in dogs. Not every dog responds to every NSAID so it may be necessary to try several before finding one that works. For dogs that are really painful, these may be used every day. In some dogs, they may be used only periodically when symptoms are worse. These drugs are very safe in dogs but do have some side-effects. The most common side effect is upset stomach. In rare cases, there can be damage to the liver or kidneys. If a dog is going to be on these medications, routine monitoring is important. Blood work should be done both before the medication is started and regularly as long as it is taking them. The medication should be stopped if vomiting, diarrhea, lack of appetite, or yellowing of the gums or eyes is noted.


• More powerful opiods or narcotics. These types of drugs are usually only used for dogs that need more pain relief than they get from NSAIDS or dogs that cannot take NSAIDS.


• Acupuncture. Acupuncture is a very viable treatment option for many dogs with osteoarthritis. With acupuncture, you may be able to reduce the number of other medications that your dog needs. In some cases, other medications may be eliminated except for those times when the dog is extremely painful. Acupuncture does not help all dogs. Make sure that you see a certified veterinary acupuncturist for therapy.


• Weight maintenance/reduction. If a dog is overweight, this puts more stress on its joints and makes moving around that much more painful and difficult. Reducing weight to an appropriate level can help to decrease pain. Because a dog with osteoarthritis cannot exercise much, it will lose weight more slowly than a dog that is not in pain. Patience along with appropriate dietary changes and an exercise routine can pay off.


• Controlled exercise. Maintaining an easy, slow exercise routine may help a dog with arthritis. This may consist of ten to twenty minutes of daily swimming or walking. This type of exercise helps the dog to maintain the muscle mass surrounding the joints. Increased muscle mass provides better support for joints and helps to maintain flexibility all of which may help with pain relief.

The video below discusses some of the medications that are most commonly used to treat arthritis in dogs.