We found this wonderful article on Arthritis in Dog written by a knowledgeable vet Jo who is a veterinarian blogger.  Please go to her site to read more wonderful articles:  http://creatureclinic.com/

Here is the first installment of 7 Ways to Ease Arthritis Pain in Dogs

 Arthritis in Dogs, What is it?

Arthritis in dogs, also known as osteoarthritis or degenerative joint disease (DJD), is a very common degenerative condition of the joints in dogs.  There are actually a few different types of arthritis, but the focus of this article is osteoarthritis.  It tends to occur most commonly in the hip, elbow, stifle (knee), carpus (wrist), and intervertebral joints (spine), although it can raise it’s ugly head any place in the body where you have a joint and some cartilage.

The most common sites of  arthritis in dogs

Arthritis can occur for a variety of reasons, including trauma, abnormal loads on joints, and congenital abnormalities like dysplasia.  Commonly it is simply due to wear and tear of the cartilage within the joints.  For this reason it tends to strike older dogs most frequently.  Cats are also afflicted, but tend to be better at hiding their discomfort.  I will discuss our feline friends in another post.

So cartilage is a lovely shock absorber, and when it’s damaged or absent, we end up with bones rubbing against each other, which is seriously painful (it makes me shudder just thinking about it!) and creates inflammation.

Osteoarthritis in canine hips

Of the four hips pictured above, only the one with the red arrow is normal.  See how the ball is lovely and round and sits nicely in the socket?  That dog’s other (left) hip is subluxated, which means it’s not sitting all the way in the socket.  Hopefully anyone can see that both of the hips in the right hand photo are flipping awful.  This is severe DJD.  The balls are no longer round at all and don’t sit in their sockets.  There are a lot of changes to the bone as a result of chronic instability and abnormal loads.  Interestingly (or frustratingly!) the changes we see on xray don’t always correlate well with the degree of discomfort the patient is in.  Sometimes fairly normal looking hips are painful, and while occasionally dogs with atrocious radiographs seem to get around pretty well.

Elbow osteoarthritis in a dog

Elbows tend to be a little more subtle than hips.  The one on the left is normal.  The one on the right is showing signs of arthritis, the most obvious of which I’ve pointed at with the red arrows.  It sort of looks like fluffy bone where there should be a nice smooth surface, and the easiest way to appreciate it is to compare to the normal one.

Source:  http://creatureclinic.com/arthritis-in-dogs/