At a glance
About: Osteoarthritis is a painful condition in which the shock-absorbing cartilage which cushions the joints wears down and is eventually lost.
Causes: Obesity is the most common cause of osteoarthritis in cats. Other causes include obesity, hip dysplasia, misalignment or previous trauma.
Symptoms: Reluctance to jump, decreased grooming which leads to an unkempt appearance, dislike of being touched, hiding, soiling outside the litter box, loss of appetite.
Diagnosis: Complete physical examination and diagnostic imaging to determine the extent of the damage.
Treatment: Lifestyle changes such as helping your cat to groom, food bowls and litter trays which are easy to access. Medical management with analgesics and disease-modifying osteoarthritis drugs and nutriceuticals such as glucosamine and chondroitin sulfate.
Osteoarthritis (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 primary or secondary. Primary osteoarthritis has no known cause, secondary osteoarthritis, the most common form, occurs due to changes in the joint caused by abnormal force or overuse. Most commonly affected areas are the shoulders, elbows, hips and ankle joints. Osteoarthritis can affect one joint or several joints.
Do some cats have a higher risk of developing arthritis?
Cats of any breed can develop osteoarthritis; however, some breeds are more prone to developing osteoarthritis, these include the Maine Coon who have a higher incidence of hip dysplasia and the Scottish Fold due to bone and cartilage abnormalities.
Arthritis is a commonly under-diagnosed condition, and by the time symptoms present, the cat is in a great deal of discomfort.
Studies have revealed the following:
- 20% of cats over 1 have some signs of arthritis
- 60% of cats over 6 have arthritis
- 90% of cats over 12 have arthritis
The statistics above highlight the importance of regular veterinary examinations, at least once a year for cats 0-6 and twice a year for cats over 6, early intervention can slow down the progress of the disease and help to reduce the discomfort and pain associated with arthritis.
Arthritis can occur in cats of any age; however, it is much more common in senior cats
Obese cats or cats who have had fractures in the past are also at higher risk.
There are several other contributing factors, including:
- Past injury or trauma to the joint
- Congenital bone or joint problems
- Recurrent damage to the joint
- Misalignment of the joint
- Congenital disorders such as hip dysplasia
- General aging
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, which 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.
- Reduced mobility
- Avoiding using the affected joint
- Reluctance to jump or jumping in several steps (i.e., jumping onto the sofa and then a shelf instead of leaping onto the shelf from the floor)
- Stiff gait, particularly first thing in the morning or after waking from a nap
- Swelling around the joints
- Loss of muscle mass, particularly in the back end
- Pain in specific areas you touch
- Overgrown claws due to sharpening the claws less
- Unkempt coat due to difficulty grooming
- Hunting less than before
- 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
- Urinating and defecating outside the litter tray
Cold or wet conditions exacerbate symptoms.
Your vet will do a physical exam of your cat and obtain a medical history from you including symptoms such as stiffness upon waking, reduced mobility, reluctance to jump.
- X-ray: Which will reveal changes to the joint and can determine the extent of the damage.
- Synovial fluid collection and analysis: Synovial fluid is a thick fluid which helps to lubricate and cushion the joints. This test involves collecting a sample of synovial fluid with a needle and evaluating it to rule out an infection of the joint.
Arthritis is an incurable condition, and the goal is to slow down the progression of the disease and relieve pain, but pet carers must be aware that treatment is lifelong. 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.
- Provide warmth to the affected area which may include the use of a heating pad where your cat sleeps. Keep the bed in a warm and draft-free spot.
- Place litter trays and food bowls in an easily accessible area and if you live in a multi-level house, keep food and water bowls as well as a litter tray on each level.
- Litter trays should have low sides.
- Brush your cat’s coat regularly as grooming is often difficult for a cat with arthritis.
- Trim the claws every six weeks; most veterinary practices will do this for free or a minimal cost if you can not do this at home.
- Add ramps to high up spots your cat likes to frequent, such as window ledges and cat towers.
- Provide comfortable beds with plenty of padding.
Nonsteroidal anti-inflammatory drugs (NSAIDs) – Drugs such as Metacam (meloxicam) to treat inflammation, relieve pain and increase mobility.
Disease-modifying osteoarthritis drugs (DMOAD) – These medications which can slow down the progression of the disease as well as provide relief from pain and inflammation.
- Zydax is a DMOAD which is administered once a week for four weeks by injection and helps to stimulate cartilage producing cells to produce healthy cartilage, stimultes joint capsule cells to produce lubricating joint fluid, slows cartilage damage, improves blood flow and nutrition to the joints and reduces swelling and inflammation.
- Adequan is not labelled for use in cats, but some veterinarians do administer it as an extra-label medication. It works to stimulate the production of new cartilage, restores synovial lubrication and inhibits enzymes responsible for attacking cartilage and synovial fluid.
These are foods or food compounds which have a medical benefit. The FDA does not regulate nutraceuticals. 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 – A naturally occurring molecule and vital part of cartilage that is believed may stop cartilage degrading along with drawing water to the joint.
- Omega 3 fatty acids – Natural anti-inflammatory supplements which can be added to food.
- Arthrodesis – A procedure to fuse joint surfaces together.
- Reconstructive procedures to treat anatomic defects.
- Acupuncture – Fine needles are placed in several trigger points to alleviate pain.
- Cold laser therapy – This new FDA approved treatment which uses an infrared laser to heal, regenerate, and protect tissue that has been injured, is degenerating, or else is at risk of dying.
Keep a close eye on your cat’s weight, the more weight he puts on, the greater the stress on the joints.