What is feline osteoarthritis?
Also known as degenerative joint disease (DJD), osteoarthritis (osteo-bone, arthro-joint, itis-inflammation) is a condition characterised by the breakdown of the joints and surrounding tissues. Cartilage is the smooth, slippery tissue over the ends of the bones in the joints which acts as a cushion and shock absorber, allowing the bones to glide over each other. When osteoarthritis develops this slippery layer breaks down and wears away exposing the bones causing pain, inflammation, and stiffness. As the disease progresses, loss of movement can occur in the affected joint.
The cartilage has no nerves, however, there are nerves in the bones so when the bones of the joints rub together, this leads to pain, swelling, and loss of movement. Eventually, the bone may lose its shape. Bony spurs (osteophytes) and thickening of the bone may result. Pieces of bone and cartilage may break off causing more pain and inflammation.
Osteoarthritis can be divided into primary and secondary. Primary osteoarthritis has no known cause, secondary osteoarthritis, which is the most common form, occurs due to changes in the joint caused by abnormal force or overuse. Shoulders, elbows, hips and ankle joints are most commonly affected. Osteoarthritis can affect one joint or several joints.
Cats of any breed can develop osteoarthritis, however, some breeds are more prone to developing osteoarthritis, these include Maine Coons who are more prone to developing hip dysplasia and Scottish Folds due to bone and cartilage abnormalities.
What causes osteoarthritis in cats?
Arthritis can occur in cats of any age, however, it is much more common in senior cats (particularly cats over 12 years), obese cats and/or cats who have had fractures in the past.
There are a number of other contributing factors, including:
Injury and trauma to the joint.
Congenital bone or joint problems.
Recurrent injury to the joint.
What are the symptoms of arthritis in cats?
Symptoms of osteoarthritis are generally progressive, occurring over months or even years. Cats are exceptional at hiding pain and discomfort, so symptoms may be subtle. This is why it is so important for cat owners to be aware of their cat's habits and behaviours, even subtle changes should warrant investigation.
- Difficulty walking.
- Avoiding using the affected joint, for example, my Burmese has arthritis in one leg and will often avoid putting any weight on the leg.
- Decrease in activity and/or reluctance to jump.
- Stiff gait, particularly first thing in the morning or after waking from a nap.
- Swelling around the joints.
- Muscle atrophy on the affected limb.
- Pain in specific areas you touch. Some cats may lash out if you touch them in specific areas, again, our Burmese girl (who was generally a sweet and affectionate cat) would often bat us if we handled her as it obviously caused her pain.
- Claws may become overgrown as your cat becomes reluctant to sharpen them due to pain.
- Cats with arthritis often have difficulty grooming due to pain.
- Weight gain (due to moving around less) or weight loss (due to loss of appetite caused by pain).
- Change to sleeping pattern, trouble settling down and getting comfortable, sleeping more or sleeping less.
- Changes to routine, sleeping in different spots, going outside less.
- Poor coat condition due to discomfort grooming.
These symptoms may be exacerbated in during cold or wet weather conditions.
How is feline arthritis diagnosed?
Your vet will do a physical exam of your cat and ask about his history. He will need to perform some tests, including:
X-ray - Which will reveal changes to the joint and can determine the extent of the damage. This will be performed either under general, or sedation.
Examination of the joint fluid may be performed to exclude joint infections.
How is feline arthritis treated?
Arthritis is an incurable condition. Treatment is aimed at slowing down the progression of the disease and making your cat comfortable. Early diagnosis of osteoarthritis important in helping minimise pain and further damage to the affected joint(s).
If your cat is overweight, careful weight loss and increased exercise will be necessary to reduce pressure on the joints.
Providing warmth to the affected area. This may include the use of a heating pad where your cat sleeps. It's important to ensure your cat's bed is in a warm and draft-free spot.
Place litter trays and food bowls in an easily accessible area.
Nonsteroidal anti-inflammatory drugs (NSAIDs) may be prescribed. These drugs reduce inflammation, relieve pain and increase mobility.
These are foods or food compounds which have a medical benefit. Unlike drugs, nutraceuticals are not regulated by the FDA. Always consult with your veterinarian before giving your cat these products.
Glucosamine - Glucosamine is a sugar produced by the body and a building block of cartilage. Glucosamine supplements can help to slow the breakdown of cartilage and help damaged cartilage to heal.
Chondroitin sulfate is a naturally occurring molecule and vital part of cartilage that is believed may stop cartilage degrading along with drawing water to the joint.
enhances the formation of cartilage and inhibits enzymes in the joint, which tend to break down cartilage.
Arthrodesis is sometimes recommended. This involves fusion of the joint surfaces. Reconstructive procedures may be performed if the cause of the osteoarthritis is caused by anatomic defects in the joint(s).
Preventing arthritis in cats:
Keep a close eye on your cat's weight, the more weight he puts on, the greater the stress on the joints.