Your dog's knee joint consists of the bones of the femur and tibia; the actual kneecap, called the patella; the small fabellae; the cartilage of the medial and lateral menisci, and the cranial and caudal cruciate ligaments. You got it—there's a lot that can go wrong here.
One of the most common canine knee joint problems occurs when the patella luxates. In simple terms, the kneecap becomes dislocated. While patella luxation can happen to any dog, it's frequently found in small breeds. If your dog experiences a dislocated kneecap, he might limp or appear to "skip" when he moves. That is, he limps a bit, then starts moving normally. The lameness gets worse over time. He might not want to jump up on anything or anyone.
Although patella luxation might occur due to an injury, more often it's hereditary. Some cases are congenital, meaning the dog was born with a predisposition for kneecap displacement. According to the Canadian Veterinary Journal, female dogs are more likely to experience luxating patellas than males.
Some dogs with luxated patellas don't show any signs of lameness at all. In that case, your vet may take a "wait-and-see" attitude. If your dog experiences lameness, surgery offers a very good prognosis.
Ruptured Cruciate Ligament
Another common knee problem occurs when the cruciate ligament ruptures. If oen of your dog's hind legs is suddenly lame, more than likely he tore the cruciate. He's obviously hurting. You may think the leg is broken because he won't bear weight on it. If you don't take him to the vet right away, the leg might appear to get better, but the knee will swell up. Untreated, the knee will almost certainly become arthritic.
Surgery is the preferred way to deal with a ruptured cruciate ligament. The type of surgery depends on the tear's severity and the size of the dog. After surgery, dogs must rest and go through some physical therapy. It can take a few months before your dog can resume all his normal doggie activities. Since surgery is expensive, some dog owners may opt for a prolonged period of very limited activity while the dog heals. The vet might prescribe anti-inflammatories and other medications to help the dog.
While you can't always prevent a ruptured cruciate ligament, there are ways to lower your odds. Don't let your dog get fat. Overweight animals put more stress on all joints. In fact, if your fat dog ruptures one cruciate, it's likely the other one will also rupture down the line. As ligaments, like just about everything else, weaken with age, older dogs might rupture the cruciate without much exertion.
Jane Meggitt has been a writer for more than 20 years. In addition to reporting for a major newspaper chain, she has been published in "Horse News," "Suburban Classic," "Hoof Beats," "Equine Journal" and other publications. She has a Bachelor of Arts in English from New York University and an Associate of Arts from the American Academy of Dramatics Arts, New York City.