According to one recent study, canine osteoarthritis strikes an estimated one in five adult dogs-or roughly 20 percent of the forty-four million adult dogs in the United States. This same study indicates that dogs most at risk of developing osteoarthritis are large breeds, geriatric dogs, active dogs (e.g., working or sporting dogs), and those with inherited joint abnormalities such as hip or elbow dysplasia.
This study does not represent the whole picture when it comes to pets suffering from arthritis. For one, it doesn’t touch on other species, such as cats, who can suffer from chronic arthritic pain, too. Also, the number of pets estimated to have arthritis could be low for the simple reason that pet owners often do not recognize an animal’s signs of chronic pain and the pet’s arthritis is left untreated (and unreported). The study estimates that more than half of the mild arthritis cases and 44 percent of the moderate cases go untreated. Nearly 20 percent of severe cases receive no veterinary care either.
Types of Arthritis
Though there are more than one hundred diseases that can cause arthritis in pets, true arthritis (as opposed to diseases that cause arthritis-like symptoms) is an inflammation of the joint and can come in
many forms, with the two most common being osteoarthritis and rheumatoid arthritis.
Osteoarthritis, the more prevalent of the two, is a degenerative disease that affects joint cartilage, causing it to wear roughly, ulcerate, and in some cases dissolve or disappear, leaving a cushionless bone-on-bone joint. The onset of osteoarthritis can be caused by a developmental or degenerative disease that creates joint instability, which in turn causes the production of painful and destructive bony spurs. Dogs who suffer from hip dysplasia, elbow dysplasia, or other musculoskeletal problems are often at increased risk of developing arthritis as they age. A direct injury that has caused ligament, cartilage, or bone damage to the joint can also increase an animal’s risk of developing osteoarthritis.
Old age, per se, is not a cause of arthritis, but an older dog who has been very active in life has more opportunities for wear and tear on his joints than his less-active, younger counterparts. Heavy animals put more stress on their joints than do lightweight animals and therefore run a greater risk of developing arthritic joints. Also, chondrodysplastic breeds-those with abnormally short bone growth commonly in the legs, such as Dachshunds and basset hounds-often have unstable disks in their backs or necks, which can lead to arthritis.