Pets

Too many options?

This article is aimed at clarifying what are the main players in the medical treatment of osteoarthritis

Antiarthritic drug review

 The plethora of new drugs for this common disease of old age makes treatment choice increasingly difficult rather than easier. This article is aimed at clarifying what are the main players in the medical treatment of osteoarthritis (OA).
Arthrodeses are joints. Arthritis refers to joint inflammation. Arthritis is a common disease in the older dog and cat.
Inflamed joints are often painful and can feel swollen and hot with limited pain free movement.
We can do one of two things to help the arthritic joint.

  1. Offer pain relief and reduce the inflammation
  2. Slow or reverse the degeneration within the joint

Keeping this division in mind allows us to more easily understand the drugs available, and when and where they are best used.
As long as these drugs are compatible you can see it makes sense to try and use them in combination for the most effective approach.

Pain Relievers / Anti-inflammatory Drugs

Steroids

Are particularly useful for bad backs (NSAID’s not being very useful for such pain). They are also the number 1 choice for polyarthropathies (ie multiple joint disease involvement) especially in immune mediated disease.
We try to avoid long term steroid use, especially in dogs as it interferes significantly with the adrenal glands and therefore has may side effects. However when indicated they are a very effective anti-inflammatory, and to a lesser extend a pain reliever.
Steroids should never be used concurrently with Conventional NSAID’s (see below).

Conventional NSAID’s

NSAID’s are Non-Steroidal Anti-Inflammatory Drugs. Zubrin, Metacam, Previcox, Rimadyl and Tolfedine are the ones most commonly used at Seaforth Vets. These are basically pain relievers / anti-inflammatories of a non-steroidal nature.
Think of aspirin as the original NSAID. Aspirin is not very effective, can be toxic in cats, is too short an acting drug in dogs and has poor safety margins when used long term with respect to ulceration of the GI tract.
All the newer NSAID’s are aimed at convenience (once daily dosing, more palatable), are far more effect pain relievers and the most recent push is to greater safely margins for long term use, Previcox having the best safely margin to date (for dogs).
Tolfedine is the number one product for cats, but Metacam at low doses has proved safe and effect for long term use. (Despite not being specifically licensed for use in cats).
Conventional NSAID’s should never be used concurrently with steroids.

Non-conventional NSAID’s

Essential Fatty Acids / EFA’s ( Hill’s new J/D diet, Waltham’s Mobility Support, Benelox, and in green lipped mussel extract)

Essential Fatty Acids have been around for years and have been variably successful in helping alleviate chronic skin allergies, but rarely produce outstanding results in practice. A newer novel use is in the treatment of OA.
High omega –3 fatty acids and a low ratio of omega 6 to omega 3 is claimed to be the key. Omega 3 fatty acids interfere with the production of inflammatory intermediates that can contribute to the destruction of cartilage.
Recent research suggests that 50% of patients showed improved mobility in as a little as 3 weeks after feeding Hill’s j/d diet.
There is no problem using EFA’s in conjunction with any other form of OA drugs. They are a nice safe, if mild alternative and probably most useful in low grade / early OA.

Joint modifying drugs

Once we have offered our patients pain relief it makes good sense to try and produce amore positive outcome for the affected joint. In other words effect a treatment rather than just mask the signs of pain and inflammation. Joint modifying drugs are slow in onset, while pain relievers will work within 1-2 hours of the first dose. Hence it makes sense to start with both medications and if possible wean off the pain relievers when joint improvements are under way. Many times this is not possible and both medications are used in conjunction.
Recently many companies have jumped on the bandwagon in producing various forms of these drugs.

Pentosan Polysulphate: (Cartrophen)

By injection or available as capsules. This drug was the original alternative medicine for arthritis. Produced originally for veterinary use it has also since proved useful in the human field. This drug inhibits enzymes involved in cartilage destruction and stimulates cartilage renewal and repair. In other words it attempts to reverse / slow the chronic degenerative changes seen in the arthritic joint. It is our number one choice adjunct to pain relievers and is safe to use in conjunction with any of the above. In many instances it is used as a stand-alone treatment for OA in cats and especially dogs.
 

Glycosaminoglycans (GAG)

Glycosaminoglycans are long chained molecules, which are involved in the formation and repair of cartilage. Glucosamine and chondroitin are precursors that help go to make up these molecules. Thus it is argued that they can help promote long-term protection in preventing degeneration of cartilage. The idea is to provide the components for cartilage formation. The long chain GAG’s themselves will not absorb intact through the gut wall. The general feeling in the veterinary field is that these drugs do help.

Glucosamine / chondroitin sulphate (Cosequin, Sharks cartilage and also in Sasha’s blend)
Nutritional supplement for cartilage support in dogs.
Glucosamine is a modified sugar that occurs naturally in the body. Chondroitin is also a simple molecule that occurs naturally in the body. Both major components of cartilage -- the tough, connective tissue that cushions the joints. Chondroitin helps to keep cartilage resilient by absorbing fluid (particularly water) into the connective tissue. It is also believed to block enzymes that break down cartilage and it provides the building blocks needed for cartilage to repair itself.

New Zealand Green lipped mussel extract (In Sasha’s blend)
The Green Lipped Mussel is most commonly found growing in the sea off the coast of Australia and New Zealand. It is the flesh of the Green Lipped Mussel that is processed into a powdered form and then into tablets or capsules.
Green Lipped Mussel is a source of chondroitin and other glycosaminoglycans. Green Lipped Mussel also has anti-inflammatory properties that may be due to the essential fatty acids and natural antioxidants found in the Mussel flesh.

Physio and Acupuncture

Acupuncture may occasionally prove useful, but is generally a treatment mode used when all else fails due to the variability of its effectiveness.
Physio can be a good adjunct to any of the above medicines. These days Australia has people trained specifically in animal physio. To become an animal physiotherapist one must first be a fully qualified human physiotherapist, so these people do have a lot of experience! However as they are not trained veterinarians and have to work under direction from a qualified veterinarian.
At Seaforth Vets we occasionally invite Khristine Edwards of Leichardt to carry out physio on a number of our patients. If you wish to know more about this approach you can contact Khristine at ke13@netspace.net.au.
I hope this article gives you a clearer picture of what is happening in the rapidly developing field of anti arthritic medicines.
But remember! 50% OF THE TREATMENT of OA in overweight animals is weight loss and in all cases the cessation of any vigorous exercise is recommended. More short walks that single long walks are the way to go. Do not over exercise the OA animal.