Luxating patella is a condition most commonly affecting smaller, bow-legged breeds like Jack Russells, Pomeranians and Toy Poodles. It also occurs in larger breeds like Labradors and can occur in cats. There is a similar condition called locking stifle in horses too.
The kneecap (or patella) pops out of it's groove in the knee and dislocates. This causes a skip in the dog's step. It often looks like the dog is running on three legs and then suddenly goes back to normal.
It often happens due to the shape of the leg. In bow-legged dogs, the leg isn't straight so when the muscles pull on the kneecap, the force occurs at an angle and pulls the kneecap to the side. Overtime this wears the groove down so the kneecap is easier to dislodge.
There are different grades in severity from 1-4. Depending on the grade, the dog may require surgery or it could be managed conservatively with physiotherapy.
The condition also affects both knees in 50% of dogs. Patients are more likely to develop cranial cruciate disease and osteoarthritis due to the extra strain on the joint. These factors are both things to consider for long term management of the disease.
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