Arthritis in Cats

It is well recognised that older dogs suffer from joint discomfort and many pet owners are familiar with the medication dispensed by vets to relieve their pain.  However until recently, feline osteoarthritis (OA) has not been commonly diagnosed or treated mainly due to the cats’ survival instinct to hide signs of pain and the lack of recognition of the condition by owners and veterinary surgeons.

Incidence of osteoarthritis in cats

Due to the challenges of diagnosing arthritis in cats, it can be difficult to tell how many cats are affected.  However, recent studies looking at radiographs of older cats showed 90% of cats over 12 years had evidence of OA (Hardie et al, 2002).  This study and others suggest that it is very common in older cats and therefore is being under-diagnosed.

What causes osteoarthritis?

OA is a type of arthritis in which the normal cartilage that cushions the joint is worn away, exposing the bone and resulting in discomfort.  There are some factors that can contribute to the development of OA.  These include:

• Genetics: certain breeds appear to be predisposed to developing arthritis due to various underlying joint problems, for example hip dysplasia in Maine Coons and patella luxation in the Abyssinian. Scottish Folds are particularly prone to OA affecting multiple joints and Burmese cats are thought to suffer with elbow arthritis more than other breeds.
• Injury causing abnormal joint loading: fractures, dislocations and other injuries can cause the joint to be used differently and result in secondary OA of the affected joint.
• Obesity: obesity does not cause arthritis but it will exacerbate the condition.
• Acromegaly: this unusual hormonal disease results in diabetes mellitus and some cats also develop arthritic joints.

What are the signs of osteoarthritis?

The most obvious sign of arthritis is joint pain, with the most commonly affected joints being the elbows, stifles (knees) and hips.  However, this is where the problem arises; cats are the masters of hiding discomfort and do not demonstrate the obvious signs of pain.  They are not taken for walks like dogs and restrict their own activity to minimise the use of the sore joints.  They also tend not to show the same obvious signs of pain as other species (e.g. vocalising), exhibiting more 'passive' behaviour to disguise pain.

Signs of pain in cats that owners may observe and report to the vet include the following:

• Reduced mobility
• Reluctance to jump up or down from furniture
• Sleeping in different, easier to access sites
• Difficulty using the cat flap
• Lameness or stiff/stilted gait – this is relatively uncommon as often multiple joints are affected and so the lameness is disguised
• Litter tray accidents, missing the tray, reluctance to climb into high sided tray
• Changes in grooming behaviour
• Matted and scurfy coat
• Over-grooming painful joints
• Temperament changes
• Reduced interaction, e.g., lack of response to petting
• Lack of tolerance of handling, children, other pets
• Changes in activity level
• Playing and going outside less frequently
• Not hunting or exploring the outdoor environment as frequently
• Overgrown claws due to lack of activity 

On examination affected cats may demonstrate discomfort and resist palpation and movement of the affected joints.  The joints may feel firm and swollen.  Orthopaedic examination can be challenging in cats, as they are often reluctant to walk normally in a consulting room.  Being gentle and not rushing will help the cat relax and behave more normally, facilitating a more rewarding examination.  The next step in the diagnosis involves  radiography.  Ideally two views are taken of the affected joints and changes include the formation of new bone around the joint margins (the bodies attempt to ‘stabilise’ the joint).  Sclerosis (thickening) of the underlying bone and narrowing of the joint space are also observed.  Further laboratory tests are not usually required to diagnose osteoarthritis, however as affected cats tend to be older and may have more than one disease, a full investigation should be performed before prescribing medication. 

Management of the arthritic cat

Treating arthritis in cats doesn't start and finish with a pill or potion.  Home comforts and management adjustments are vital to the improving the cats' quality of life and can be just as important as medications.

Easy home and management adjustments for the arthritic cat

• Provide soft beds for sore joints in easily accessible, quiet places
• Place beds in quiet, draft free areas of the house
• Igloo beds or cardboard boxes can make an older cat feel warm and secure
• Provide 'steps' up to higher sites, e.g., the sofa, the cat flap
• Tie the cat flap open so the cat doesn't need to push through
• Always have a litter tray inside and use a low sided version or cut out the sides to make it easy for arthritic cats to climb in
• Use different types of litter that are softer for sore feet
• Make sure food and water are easily accessible, at floor level or with steps up to higher levels
• Put food, water and litter trays on one level to avoid the cat having to go up and down stairs
• Radiator beds are popular but again arthritic cats will need help to get into them, other warming devices such as wheat bags can help but electrical devices should be used only when the cat is monitored
• Arthritic cats may need extra grooming and help cleaning eyes and perineal region
• Overgrown claws need regular cutting

Nutritional management and nutraceuticals

Obesity will exacerbate OA and so should be avoided.  Obese cats need careful diet changes supervised by a veterinary surgeon.  Overweight cats need to lose weight slowly and changes may take several months.  Rapid weight loss can result in metabolic problems such as hepatic lipidosis when a large amount of fat accumulates in the liver.

Several dietary supplements and diets are available for cats with OA containing combinations of essential fatty acids (EFAs) (to reduce inflammation), natural glycosaminoglycans (to help improve cartilage quality), anti-oxidants (reduced free-radical damage), methionine, manganese and selenium (to assist cartilage synthesis) (Hills Prescription food j/d).

Nutraceuticals

Chondroitin and glucosamine supplements are available for cats.  The affects are unproven but they have been shown to be effective in dogs, horses and people and so may be beneficial.  They may help in early or mild cases but are not likely to be enough alone in more severe cases.

Medical treatment

Medications can be very effective at controlling pain but should only be used once the cat has been fully assessed for their general health and the presence of other diseases.  Most cats with arthritis are geriatric and so commonly suffer concurrent disease.  Ideally cats should have a full blood test and urinalysis prior to commencement of medication.

The most common medication used and the only medication to have a license for the treatment of chronic pain caused by OA in cats is Meloxicam.  This drug is very effective for treating pain but should be avoided in cats with kidney problems, liver problems, vomiting/diarrhoea or any cat that is dehydrated or has low blood pressure (hypotension).  The lowest effective dose should be used and the drug must be given with food.  Maximising water intake is important in all older cats (to prevent dehydration and urinary problems) and this is especially true of cats receiving Meloxicam (water fountains, wet food diet etc). For more information about NSAIDS and cat refer to our information page here.

Alternative drugs have been used including opioids (buprenorphine which can be given sublingually), tramadol and gabapentin.  These drugs are not licensed for use in cats with osteoarthritis and so have not been closely studied.  Anecdotal reports suggest they may be useful in cases where Meloxicam in not appropriate.  Corticosteroids are not recommended as they cause side effects and can result in long term health problems such as diabetes.

In conclusion OA is common in older cats and is challenging to identify.  Diagnosis relies on an observant owner and a veterinary surgeon asking the right questions and using cat friendly practice principles when approaching the examination and management.  Medications can be very effective and improve a cat’s quality of life but concurrent geriatric disease should be considered before such drugs are prescribed.  The importance of management changes can not be over-estimated.

Our Midland & Drovers Vet Hospitals are both accredited ISFM Cat Friendly Clinics.

The Cat Friendly Clinic programme is an internationally recognised assessment accreditation scheme which is open to any veterinary practice that cares for feline patients. There are certain requirements regarding design, equipment and facilities within the clinic, which must be met to achieve the standard. The clinic must also demonstrate that a high quality of care is provided to cats and that all staff understand cats and their needs in a clinic.

The benefit to the clinic is that not only will the scheme help to improve the clinical care of feline patients but may also increase the number of clients who are actively seeking a cat friendly clinic for their pet.