The thyroid glands are small organs found just under the skin, either side of the windpipe in the neck. These glands produce thyroid hormone which helps to regulate your cat’s metabolism, or rate of bodily activity. Production of thyroid hormone is normally closely regulated in the body as the effects of too much (or too little) can be very serious. Hyperthyroidism is a disease caused by overactivity of these glands. When the thyroid gland produces too much hormone, your cat’s ‘internal motor’ effectively goes into overdrive. Untreated this would eventually be fatal but the condition can be successfully treated.
What is arthritis?
In the normal joint the bone surfaces are covered with a thin layer of smooth cartilage. This is lubricated with a small amount of joint fluid. This structure allows the two surfaces of the joint to slide freely over one another. In animals with arthritis (also known as osteoarthritis) the cartilage in the joint degenerates and becomes damaged and thinned. The bone surfaces begin to rub together (rather than gliding) causing discomfort as well as further damage to the cartilage. With time new bone may form around the joint and this can cause the joint to become stiff and limit joint movement. Depending on the cause, arthritis may affect just one or any number of joints.
What causes arthritis?
In most cases arthritis develops due to abnormal wear within the joint. This can be due to:
- ∙Instability of the joints, e.g., when ligaments have been damaged
- ∙Damage to or abnormal development of the cartilage in the joint or
- ∙Damage caused by trauma such as joint fractures and chronic sprains.
How would I know if my dog had arthritis?
Arthritis causes pain and stiffness in the joints. If your pet has arthritis, you may notice they are not as keen to exercise as in the past and they may limp or seem to be stiff (particularly when getting up from rest). This stiffness may get better after being out for a walk, and sometimes cold and/or damp weather may appear to make signs worse. Dogs will sometimes lick continually at a painful joint and in dogs with pale colored coats the saliva may start to stain the fur over the affected joint. Occasionally the joint may appear hot or swollen but usually you will not be able to recognize any change in the joint. The signs in some animals can be obvious whereas other pets may just become quieter or grumpier if they are in discomfort.
How will my veterinarian know if my dog has arthritis?
Your veterinarian may suspect that your pet has arthritis from the signs you describe. By examining your pet your veterinarian should be able to identify which joints are painful, stiff or swollen. To find out more about what is going on inside the joint your veterinarian may need to do further tests. X-rays of the joint will help to confirm the presence of arthritis and to identify any underlying causes.
Is there any treatment for arthritis?
The treatment for arthritis depends upon the underlying cause and the joint(s) affected. In almost all cases arthritis is worse in animals that are overweight and unfit. Treatment of osteoarthritis must be aimed at keeping the joint in use, minimizing discomfort, and preserving the structures of the joint for as long as possible. Without a doubt the most important therapy for patients with osteoarthritis is the combination of weight control and exercise management, minimizing the load on the joint, and maximizing the range of movement and the fitness of the muscles around the joint. Many patients will also benefit from drug therapy, and in some cases long-term drug therapy is useful. Initially pain relief is important and the most common veterinary analgesics used are the non-steroidal anti-inflammatory drugs (NSAIDs). If your pet has arthritis your veterinarian may need to treat them on numerous occasions over their lifetime. The treatment used will vary both from one patient to the next, and for an individual patient over time. Your veterinarian may recommend using multiple treatments, singly, or more often in combination, to provide the best immediate and long-term support for each patient.
What drugs are used to treat arthritis?
Disease modifying osteoarthritis drugs (DMOAD)
As cartilage damage is such an important part of arthritis it is clearly a good idea to try to limit this. Some drugs may reduce cartilage damage – these chondroprotective drugs are described as disease modifying osteoarthritis drugs (DMOAD). Drugs such pentosan polysulphate are suggested to reduce cartilage degeneration, promote the repair of joint structures, and reduce inflammation.
There has been a recent rise in the use of nutraceuticals—a food or naturally occurring food supplement marketed as having a beneficial effect on health. These substances include omega-3 fatty acids and glucosamine and chondroitin sulphate. Feeding nutraceuticals in the diet may provide the building blocks for the repair of cartilage within the joint, as well as reduce inflammation that can contribute to pain and further degenerative changes, and this may in turn promote relief from the signs of arthritis. Nutraceuticals have been used in the management of long-term osteoarthritis in people, and they may be a useful addition to other therapy in animals.
Non-steroidal anti-inflammatory drugs (NSAIDs)
NSAIDs are commonly prescribed for management of arthritis as they have actions against both inflammation and pain. Occasionally these drugs can cause vomiting or diarrhea as well as other side-effects. These side-effects mean that there are some warnings against their long-term use in dogs. NSAID use is quite restricted in cats as these drugs can be more toxic in this species.
Monoclonal antibodies
Monoclonal antibodies are drugs that mimic naturally occurring proteins produced by the immune system and are used in the treatment of feline and canine osteoarthritis to target Nerve Growth Factor (NGF), a key component of osteoarthritis pain, to block the release of pro-inflammatory mediators and the binding of NGF to neurons and inflammatory cells. These drugs function like the body’s naturally occurring antibodies and have minimal impact on other body systems such as the liver, kidneys and gastrointestinal tract. This means that they are often well tolerated in animals with concurrent medical issues and/or impaired hepatic and/or renal function.
In the short-term the drugs with the highest impact on analgesia and inflammation are likely to be the first choice. Often these drugs are not needed in the medium or long-term, or they are not licenced for such use due to the cumulative risk of side-effects. In such cases, particularly in cats where the therapeutic options are more limited, alternatives must be sought. New drugs are becoming available and the development of a successful management plan for arthritis in the individual patient requires regular review of the current medication and how the patient is progressing.
Will my dog get better?
Unfortunately, once the cartilage in the joint has been damaged it rarely repairs. However, although there may still be damage in the joint many pets can be made pain free by long-term use of medication and management to control further wear on the joint.
There is a great variation in the severity of arthritis between patients. Many pets cope well with their disease and lead a full and active life without any veterinary treatment. Some patients require treatment ranging from simple lifestyle changes to complex surgery. The signs of arthritis often vary throughout the animal’s life and often result in earlier onset of joint problems as animals age.
