In dogs, subluxation of the patella is called loose kneecaps. When it happens, the kneecap slips out of its groove, sometimes often and sometimes rarely, depending on how sever the problem is. It is parted in grades from 1- 4.
If the grade is higher than 2 surgery may be the solution for the dogs welfare. A dog with a gentle grade can live a normal happy life. Subluxation of the patella is a relatively common problem in small breed dogs but do accure in large ones as well.

Patella luxation/Patellaluksasjon