Arthritis and Degenerative Joint Disease
What are Arthritis and Degenerative Joint Disease (DJD)?
By definition, arthritis is inflammation in the joint and DJD refers to the progressive degenerative processes that result in pathology in a joint. These are painful conditions and in order for us to imagine what a beloved pet may feel like, all we have to do is ask a friend, neighbour or relative who suffers from arthritis, to know that it’s pretty uncomfortable.
Arthritis = Pain
The most common form of arthritis is very similar to that seen in most people, which is due to “wear and tear” of the joints over time, and therefore is seen mainly in older animals. Larger dogs seem to be more affected, however it does occur in small dogs and cats but is much harder to detect. It may involve just one joint, or many throughout the body may be involved. Arthritis can also be seen in much younger animals if they have had a joint injury, joint surgery, or if they have a congenital or hereditary joint abnormality. There are also rare forms of autoimmune arthritis (e.g. Rheumatoid arthritis).
Initially the main change in the joint is a loss of the natural lubricating quality of the joint fluid. Soon, the inflammatory changes inside the joint quickly start to damage the articular cartilage, a tough, yet shock absorbing layer of cartilage that sits over the ends of the bones inside the joint. Whilst damage to cartilage is the major issue in arthritis, there are very few nerve endings there, so pain does not start to show until the cartilage has been eroded and pain receptors in the bone underneath are stimulated. This means that once signs of arthritic pain are evident, the disease has already progressed significantly. As joint disease progresses there may be secondary changes such as extra bone being laid down around the joint in an attempt to stabilise it, which actually leads to greater joint pain and immobility.
Arthritic Pain = long standing cartilage damage
What should I look out for?
The main problem of arthritis for our pets is the pain it causes, which can be expressed in many ways. Limping or lameness, an inability to quickly get to a standing position, a reluctance to jump, exercise or play, or becoming more aggressive or grumpy, can all be signs of arthritic pain. Some pets however will not exhibit their pain, especially chronic pain, and will suffer in silence. A common myth, is that if an animal is “a bit stiff” first up in the morning but is okay after they warm up, then the arthritis is not too bad and no treatment is needed. This tends to underestimate the effect of arthritis both from the pain it causes and the fact that starting treatment at the earliest indication is better for prevention of disease progression. Many of these animals that only show transient lameness will exhibit reduced weight bearing on the affected limb, as seen on tests like the sensitive “force-plate analysis”, long after they have warmed up indicating that pain is real and on-going.
Apart from pain, some lameness or stiffness may be caused by structural deformities in the joint, changing the way it moves and therefore how the limb functions. An examination of these more severely affected joints may reveal either fluid or bony swelling, or a crunching or clicking sound when the joint is manipulated. Additionally, the affected limb may have muscle wasting due to reduced weight bearing. Sometimes x-rays may be needed to visualise the typical signs of chronic arthritis and to help rule out other diseases in the bones close to the joints.
Chronic arthritic pain continues after warming up even if stiffness improves
These signs are not specific to arthritis but when several of them occur together, there’s a pretty good indication that your pet may be suffering with arthritis:
- Difficulty rising, standing or sitting
- Slow and/or reluctant to get up
- Decrease in activity
- Decrease in interacting with family or other pets
- Disinterest in activities he/she used to enjoy e.g. playing fetch
- Hesitancy to jump up or down, run or climb stairs
- Change in temperament - becomes grumpy or aggressive
- Sleeping more
- Decrease in appetite
- Weight gain
- Appears stiff or sore, even if they seem to improve after warming up
- Swollen looking or lumpy joints.
How is arthritis/DJD diagnosed?
A clinical exam along with a thorough history of his/her clinical signs seen at home, will give the examining veterinarian a pretty good idea that arthritis is a possibility. During the exam the vet may feel fluid or boney swellings around the joint, crunching or clicking sounds when the joint is moved. He or she may also find there’s been muscle wasting because of reduced weight bearing and limb use. Radiographs (X-rays) may be needed to visualise boney changes, to make a definitive diagnosis and exclude other diseases that may occur in bones close to joints.
Once a preliminary diagnosis is made, we advise owners to trial their pets on a 1-2 week course of strong anti-inflammatory pain relieving medication, even if this is not used long-term. The medications (referred to as NSAIDS) will help to show just how much pain is being caused by the arthritis and gives us a goal for therapy. The fact is, many owners with arthritic pets will not recognise the signs of arthritis, or will consider them to be part of the ageing process. It is not until the pain is blocked out with medications that the debilitating nature of this disease can be realised.
What can be done?
Effective relief of pain caused by arthritis uses a multi-pronged attack to get the most successful outcome.
Healthy Weight: THIS IS THE MOST IMPORTANT AND EFFECTIVE, NON-DRUG NATURAL THERAPY WE HAVE AVAILABLE FOR OUR ARTHRITIC PETS. Body weight is a simple equation of energy in, versus energy out, and so to be unapologetically blunt, if your pet is overweight then, as the one with the opposable thumbs, YOU (their owner) are giving them TOO MUCH FOOD for their current level of activity and making their arthritis, and therefore their pain worse. The solution is also thankfully simple. A strict diet, no treats, gentle exercise in most cases, and letting us be your pet’s diet coach. Far from being cruel, but will be the best thing you can do for your pet. As you start to see the weight come off, the arthritic pain will lessen and their level of activity will increase. It is the absolute minimum that must be done for all arthritic patients!
Pain Medications: Non-steroidal anti-inflammatory drugs (NSAIDs) are the most commonly used pain medications. They settle the inflammation that is causing cartilage damage and provide immediate relief from pain. There are several different NSAID options and we recommend the new generation NSAID’s, including Onsior for dogs and Metacam for cats, since they are unique in their mode of action in that common gastrointestinal side effects of NSAID’s are largely eliminated. These are also the drugs we use for treatment trials and the benchmark against which we measure other therapies. For dogs we recommend a blood test every 6 months to monitor any changes to liver or kidney function. For cats, these tests must be done every 6 months since they are usually more susceptible to undetected kidney problems. Other drugs, including cortisone and morphine-type drugs, may be used in particular circumstances.
Chondro-protectives: over-the-counter supplements containing Pentosan Polysulphate, Omega 3 fatty acids, glucosamine and chondroitin sulphate. They are non-prescription remedies that help to rebuild and heal damaged cartilage and can be a longterm strategy in helping improve arthritic pain. Pentosan is an injection that goes under the skin (not into the joint) that helps the cartilage producing cells make more cartilage “factories”, and glucosamine/chondroitin supplements supply the building blocks to those cartilage factories. Each of these remedies has an effect on cartilage regeneration when working alone but will work better when used together. They also work better in the early stages of arthritis but even in severe cases may help reduce the dose of NSAIDs required to alleviate pain. We currently recommend the “PAW Osteosupport” brand.
Special Diets: veterinary prescription diets are also part of the arthritis management arsenal. They ensure the arthritic patient receives the correct levels of energy, protein, vitamins and minerals as well as additional supplements such as Omega 3s, glucosamine and chondroitin all in an easy to feed ration. Hills JD Prescription diet is the one that we recommend.
Physiotherapy and hydrotherapy: swimming is especially good for arthritic dogs since the exercise strengthens their muscles but there’s very little strain put on the joints because the water supports the animal’s body.
IMPORTANT: NEVER give your pet any human medication without checking with your vet first! Some human drugs e.g. paracetamol and ibuprofen can cause very serious illness and death.
Arthritis is common.
It can occur in dogs and cats of all ages and sizes
Treatment should be directed at controlling this disease at its earliest possible signs as this already represents significant progression of joint disease.
Recognising that our arthritic pets do not need to suffer pain, especially in their older years, and using a combined approach of weight loss, remedies to repair cartilage and drugs to control inflammation and pain, will go along way to ensuring that they enjoy a very high quality of life without you worrying that they may not be telling you about their chronic pain.
Remember, if your pet is diagnosed with arthritis, always discuss with your vet any concerns, changes to your pet’s behaviour, difficulties you’re having with medicating, feeding or exercising your pet. He or she is there to help you and your pet find a programme that helps your four-legged friend get the best out of life.
Written by Dr Bronwen Thompson for Northgate Veterinary Surgery
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