Legg-calvé-perthes Disease in Pugs

In Legg-Calvé-Perthes disease, the blood vessels supplying the femoral head — the ball portion of the hip's ball-and-socket joint — become disrupted during a period when that bone is still actively growing. Without adequate blood supply, the bone tissue begins to die, a process called avascular necrosis, and the femoral head gradually collapses and deforms under normal weight-bearing stress. Because this happens during active growth rather than in a mature joint, the resulting deformity becomes essentially permanent by the time bone growth finishes, unlike some soft-tissue injuries that heal cleanly on their own.

This condition is specifically a small and toy breed phenomenon, and it's genuinely distinct from hip dysplasia even though both eventually affect the same joint — dysplasia is a laxity and malformation issue that can occur at any age and any breed size, while Perthes disease is a vascular event confined to a specific growth window in small dogs. The exact cause of the blood supply disruption isn't fully understood, though genetics are believed to play a role given how consistently it appears in certain small breeds.

This condition responds well to surgery, and outcomes are generally good — but success depends on getting an accurate diagnosis rather than assuming a puppy limp will simply resolve on its own.

If you think your Pug has legg-calvé-perthes disease, the plan is three steps: write down what you have seen and when it started, book a veterinary appointment rather than waiting for the next flare, and take video of the behaviour or symptom before you go — the thing you are worried about rarely happens in the consulting room. Screening in the parents covers brachycephalic airway syndrome (boas), pug dog encephalitis, corneal ulcers.

What the vet visit should produce is a diagnosis and a written plan, not just reassurance: what is being ruled out, what the monitoring interval is, and which signs mean you come back sooner. Ask what the treatment costs across a year rather than per visit, because that is the number that decides whether you are managing this condition or reacting to it.

Between appointments, keep a short log — dates, what you saw, what changed. It is the single most useful thing an owner brings to a follow-up, and for legg-calvé-perthes disease it is often what separates a clear pattern from a guess.