Short answer: a dog hopping and skipping on one hind leg is a classic sign of patella luxation, and the condition is classified into grades 1 through 4 based on how often and how severely it occurs — knowing the traits of each grade helps you gauge how far it's progressed.
Why does the hopping gait happen?
The kneecap, which should glide smoothly within the knee joint, slips out of place, making it uncomfortable to extend the leg. The dog briefly holds the leg up while hopping, then returns to a normal gait once it slips back into place.
What does Grade 1 patella luxation look like?
There are almost no symptoms in daily life at this stage — the kneecap only slips out when pushed by hand and pops right back when released, so it's often not noticeable from the outside.
How is Grade 2 different from Grade 3?
At Grade 2, the dog occasionally hops while walking but the kneecap returns on its own when the leg is extended. At Grade 3, the kneecap stays out of place more often, so limping shows up more frequently.
What happens once it reaches Grade 4?
At Grade 4, the kneecap is permanently dislocated and doesn't return on its own — the dog may walk with the leg constantly bent or avoid using it altogether, and surgical correction is often needed at this stage.
Is there a way to check progression at home?
If the hopping happens more often than before, or your dog struggles noticeably when sitting down or standing up, it could be a sign of progression — if you notice these changes, get a vet check for an accurate grade assessment.
