Patella Luxation testing & scoring schemes in dogs

Patella luxation in dogs is a condition where the patella or “knee-cap” can move from its normal central position at the front of the knee or “stifle joint” to one side or the other. This condition is more common in the smaller breeds, however it may occur in large breeds and also cats.

 

In most dog breeds the most frequent direction of abnormal movement or “subluxation” is towards the midline of the dog- “medial patellar luxation”. In some cases the subluxation can be away from the midline of the dog and is called “lateral patellar luxation”.

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Sometimes, chronic cases can lead to erosion of the cartilage on the femur from the constant friction, and eventually, to osteoarthritis. In this case, pain is usually involved and lameness is more constant and severe. Occasionally, a luxating patella can lead to a ruptured cranial cruciate ligament.

Grade 0: Normal

Grade 1: the patella can be manually luxated with the stifle in full extension, but when pressure is released without manipulation of the limb the patella regains its original position in the trochlea. Spontaneous luxation of the patella during normal joint motion rarely occurs. Typically stifle and hock in a straight line with no deviation of the hock.

Grade 2: the patella can be completely luxated, but manipulation of the hind limb (flexion of the stifle) causes the patella to regain its original position in the trochlear. On physical examination, the patella luxates easily, especially when the foot is rotated.

Grade 3: the patella is found (at least once) spontaneously luxated with the animal in a standing position or it is permanently luxated but can be repositioned manually or by manipulating the limb. Very shallow or flattened trochlear.

Grade 4: the patella is permanently luxated and cannot be repositioned. May scarcely be able to walk or may move in a crouched position with both limbs partially flexed, and/or they may carry the affected limb. Trochlea is shallow, absent or even convex.

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Patella Luxation – No score higher than a 1 is permitted

Patella Luxation can occur in some Japanese Spitz dogs. We are strict on our tolerance and do not permit above Grade 1 in our lines. All Belzbentley puppies are have thorough health checks and come with a pedigree certificate to prove lineage. We believe in breeding only healthy dogs, furthering the strength and health of Japanese Spitz dogs in Australia.