When I first got my Maltese-Yorkie puppy, Mila, I learned that knee problems are common in toy and small breed dogs, so I have to be careful that she doesn’t jump from furniture very often, if at all. Yet when I brought Mila to the veterinarian just a few days ago, she told me that my six month old puppy definitely has a luxating patella in both of her back legs. This particular knee problem is common in small breed dogs.
What is a luxating patella?
A luxating patella is otherwise known as a slipping kneecap, which can cause lameness in dogs. The “patella” is the kneecap; in a normal dog, there are two bony ridges that form a deep groove in which the patella slides up and down. These structures control the activity of the quadriceps muscle by limiting the patella’s movement to one place (PetEducation.com).
In some dogs, the ridges forming this groove are too shallow, which causes the patella to “luxate”, or jump sideways out of the groove. The leg subsequently locks up, with the foot held off the ground. When this happens, the patella usually cannot return to its normal position until the quadriceps muscle relaxes and lengthens. When he feels the pain caused by the knee cap sliding across the ridges of the femur, you might hear a little yelp.
How serious is patellar luxation?
Luxating patellas are graded on a scale from one to five (VetInfo.com). The veterinarian didn’t tell me where Mila currently is on the scale, but I would guess that she is at either Grade One or Two. As far as I can tell, she doesn’t have any symptoms other than an occasional bunny-hop. The vet only discovered her luxating patellas via physical exam.
Grade One are luxations that are found in a physical exam of the dog; the patella can be luxated manually, but it doesn’t do this much on its own yet. Grade Two occurs when there is occasional spontaneous lameness, but the patella quickly returns to its normal position. Grade Three patellar luxations are more frequent bouts of lameness, and the patella does not return to its normal position on its own. Grade Four occurs when the leg cannot be straightened manually, and the dog is in a good amount of pain. Finally, Grade Five patellar luxation is when the dog won’t use his legs and the patella is permanently dislocated.
Patellar luxation can become a problem if it is ignored. Once the problem reaches a serious stage, surgery might be required. It is likely that Mila will eventually need surgery to correct her luxating patellas, but for now, I can only ensure that she refrains from jumping off furniture and avoids frequent high-impact activities.
Patella Luxation and Treatment in Dogs, VetInfo.com
Luxating Patella, PetEducation.com