For the most part, Patellar Luxation, aka Slipped Stifle, is a fairly common Toy breed and small dog genetic condition. It can also be caused by trauma. It occurs when your dog’s “knee” joint, just above the hock in the hind leg, slips. Some times it corrects itself, sometimes your veterinarian can work it back into the groove, and sometimes it may require surgery. Many veterinarians believe if it is not surgically corrected, osteoarthritis will eventually set in.
What causes Slipped Stifle?
It is believed it is a genetic deformation of the femur (thigh bone), tibia (shin bone) and stifle joint (kneecap). Normally, the patella slides smoothly and securely in the femoral groove. In affected dogs, the groove is shallow and/or deformed. The ligaments holding the patella in place become weakened, therefore making the angulation between the femur and the tibia uneven and unstable. When your dog runs, pivots, leaps up or jumps down, the patella pops out of the groove.
Another cause may be trauma, as it may also damage the joint, weakening the aligning ligaments.
Signs to watch for:
It occurs most often when your dog is racing madly around the yard, or leaping for a ball, Frisbee. While in mid-air, they will yelp in pain, they often spin around nipping at their hind leg while lifting it off the ground. They will often walk lamely for 10-30 minutes; then they are back to normal.
You will notice:
Mood changes…may become snappy when in pain
Growl or snap when you pick them up or touch their hind quarters
Walking on three legs
Even though your dog may appear to return to normal, you should have your veterinarian examine them. They may suggest an anti-inflammatory, or glucosamine, but eventually, they most likely will recommend surgery to lessen the risk of arthritis.
Given that Slipped Stifle is inherited by a defective gene, affected dogs should be spayed or neutered, so as not to perpetuate the condition.
What you can do to help your pet:
Mild to moderate exercise
Limit strenuous exercise to less weight bearing exercises, such as swimming
Breeds predisposed to Slipped Stifle include, but are not limited to:
American Cocker Spaniel
Cavalier King Charles Spaniel
English Cocker Spaniel
English Toy Spaniel
Jack Russel Terrier
Poodle (Toy and Miniature)
Toy Manchester Terrier
It should be noted, larger breeds are not unaffected. Certain larger breeds, such as the Labrador Retrievers are also prone to Slipped Stifle.
Bottom line: As your dog ages, the problem may become more frequent and it may take longer for them to recover. Don’t wait until too much joint damage is done.