Osteoarthritis or degenerative joint disease affects approximately 20% of dogs. To understand this disabling disease, we need to understand the normal joint. A normal joint consists of a cartilage layer at the end of the bones which has no nerve endings in it, surrounded by joint capsule to contain the joint fluid – a viscous shock absorbing fluid.
With wear and tear or trauma, the cartilage is damaged exposing the underlying bone which has free nerve endings present. These exposed nerve endings cause pain, and the body’s reponse is to lay down new bone (osteophytes). In addition the joint fluid becomes more watery leading to joint collapse and bone literally rubbing against bone. This condition is generally progressive meaning it gradually gets worse.
What causes osteoarthritis?
Well it can be either:
a) Primary from ongoing wear and tear, or
b) Secondary, to either developmental disease (abnormalities of growth), eg hip dysplasia, elbow dysplasia; or from a traumatic episode eg cruciate ligament rupture of the stifle (knee) or a fracture involving the joint.
What are the signs?
Dogs don’t always show signs of pain from vocalising as it can show signs of weakness in a pack situation, so sometimes we need to look for more subtle signs. These normally progress as the disease becomes more severe. Examples are:
- Reluctance to walk or play/lagging behind on walks
- Difficulty in getting up after resting
- Difficulty in climbing stairs
- Difficulty in jumping into the car or on a chair
- Limping or stiffness
- Change in character or aggression
- Reduced interaction with people
- Reduced appetite
- Increase in anxiety/clinginess
- Change in toilet behaviour
- Licking or self injury
How can it be diagnosed?
If you notice any of these signs then the first step is to consult your vet. They will be able to specifically palpate and manipulate the joints to localise the problem. Additional diagnostic procedures may then be needed such as x-rays, sampling joint fluid and manipulation under anaesthesia.
How can it be treated?
There are lots of things we can do to help to prevent progression of this condition and control pain.
- Weight loss, as joint problems are exacerbated by excess weight - as discussed last time - for those of you who read my articles!
- Comfort at home – provide a warm bed free from draughts which is thick enough to cushion the affected joints.
- Exercise – regular gentle exercise helps to maintain mobility, as joints that do not have movement may stiffen up, and also loss of muscle tone means lack of support for the joints. Care to avoid too much impact or rapid turns, which may exacerbate the condition.
- Pain killers - there are two types of pain killers:
- Non-steroidal anti-inflammatories such as Metacam and Rimadyl. These drugs are specifically licensed for dogs and help to control pain but also help to break the vicious cycle of ongoing joint damage. Drugs used in humans such as Voltaren can cause serious side effects in dogs so should not be used.
- Steroidal anti-inflammatories such as prednisone. These are potent anti-inflammatory/pain killing drugs but generally have more side effects.
- Cartilage protective agents - these are either injectable or oral
- Injectable medications eg Pentosan or Cartrophen these help to increase the viscosity of the joint fluid and help to repair some of the cartilage damage, plus help to prevent further deterioration of the joint. Initially a once weekly injection course for 4 weeks is generally prescribed.
- Oral medication eg glucosamine or chondroitin. These remedies are widely use and have a similar effect to the injectable form, however the biggest disadvantage is absorbing the molecules from the stomach, as it generally takes 2-3 months to achieve good concentrations in the joints.
Please discuss these options with your own vet.