Noninfectious osteoarthritis is the commonest form of joint disease in the aging dog, a situation not too different from that in humans.

The disease is progressive and causes few, if any, noticeable symptoms in the early stages.

It is not uncommon for a veterinarian to discover the existence of degenerative joint disease or its predisposing causes during a routine checkup even if you don’t have an aging dog.

Primary arthritis develops from the normal wear and tear of a joint with time and age.

While seen occasionally in very old dogs, it is not the commonly observed arthritis that it is in people.

The bulk of aging dog arthritis cases are secondary to disorders which happened or started earlier in life.

The following are just a few of the many such disorders:

• Obesity in any breed but especially in the large and giant breeds.

• Mechanical trauma such as falls and jumping mishaps.

• Torn ligaments in any joint but especially the stifle joint in toy or miniature poodles.

• Chronic dislocating patella (slipped knee cap), most common in toy breeds.

• Osteochondritis dissecans, a disease of young dogs.

• Hip dysplasia.

So look for any of these in your aging dog.