Centuries ago Leonardo Da Vinci said, "The smallest feline is a masterpiece." And millions of cat lovers the world over would agree. From their sleek beauty to their little sandpaper tongues and that sweet purr, to whiskers that help them navigate their world, and an astonishing flexibility and dexterity to twist and contort their bodies due to 244 bones in their body — compared to 206 in humans — cats are a glorious enigma. You either embrace their mystique or let it boggle your mind.
And while that tale of cats having nine lives is pushing it, many cat owners boast their cats have at least five. But like everyone else, cats are prone to certain health conditions that can slow them down. You may have considered arthritis if your cat is older, but hip dysplasia is likely the last problem you ever thought could put your super-athletic cat on the sidelines. But this painful orthopedic disorder, while extremely common in dogs and humans, does occur in cats, too — although relatively rarely. In fact, it's only been seen in cats for a short period in terms of diseases — the last couple of decades.
Knowing the clinical signs of hip dysplasia is the first step in seeking veterinary care, treating, and ultimately managing this potentially debilitating condition. But keep in mind, due to a cat's natural agility, low body weight, and less rigorous exercise requirements than dogs, mild and even moderate hip dysplasia may easily go undetected because the cat can still function normally. It's often not discovered until your cat is X-rayed for another reason altogether.
What is hip dysplasia?
Named for the Greek word for malformation, hip dysplasia is a genetically inherited disease characterized by the malformation of the ball-and-socket joint that connects a cat's femur, or thigh bone, to the hip. In dysplasia, a word that means abnormal development of a tissue, parts of the hip joint are abnormally shaped, misaligned, and loose, and the ball -- the knobby top end of the femur, or femural head of the thigh bone — does not fit into the socket — a cup-shaped cavity called the acetabulum at the lower end of the hip bone — correctly, and they knock and grind against each other.
This poor fit causes the femur to dislocate and move out of the joint, a process known as subluxation. This causes abnormal movement and over time the changes in the bone that develops from wear and tear can result in a worn, flattened, and misshapen femural head and a shallow acetabulum leading to degenerative joint disease. In contrast, a normally formed joint will have a ball that fits snugly inside the socket yet allows complete freedom of movement as it glides and partially rotates to allow all the cat's activities from lying down or standing up, to chasing a toy, and jumping or climbing with ease.
Are some breeds of cats predisposed to hip dysplasia?
Hip dysplasia can occur in all cats — pedigreed and non-pedigreed alike. However, it generally occurs in large, heavy-boned breeds like the Persian and Himalayan, and the Maine coon is the most commonly affected, with 20% of this breed showing symptoms. But it occurs also in lighter breeds such as the Devon Rex.
Symptoms of cat hip dysplasia
The most common clinical signs of hip dysplasia in cats are as follows:
- Limping or lameness in the hind legs.
- Staggering or swaying motion to gait and general difficulties in walking.
- Obvious discomfort upon rising.
- Hesitation before walking and shows a reluctance to run and jump and engage in any physical activity.
- Expressing pain when the hip is touched.
- Persistent licking or chewing of the hip area.
Diagnosis of cat hip dysplasia
Your veterinarian's diagnosis will be based on the symptoms and examination findings, with a definitive diagnosis achieved only through X-rays of the hip.
The severity of the disease will dictate the treatment protocol.
Treatment and management of hip dysplasia in cats
If your cat is diagnosed with hip dysplasia, it's imperative to keep her weight in check, explains Ursula Krotscheck, DVM, assistant professor of small animal surgery at Cornell University's College of Veterinary Medicine. The extra pounds will put intense pressure on the joints, causing more pain, and worsening the disease.
Your vet will give you care instructions which may include encouraging exercise to keep the hip muscles strong, such as hiding food where she will have to crouch to get it, or placing food or treats on the counter so she will need to jump up. He may prescribe anti-inflammatory medications and/or dietary supplements containing glucosamine and chondroitin, compounds that may help maintain the strength your cat's connective tissues.
In advanced cases of hip dysplasia, you may consider a surgery called micro total hip replacement in which the hip joint is removed and replaced with an artificial device. Or, as Dr. Krotscheck points out, "You can just remove the femoral head — the ball part of the hip's ball-and-socket joint — and you do not replace it. The muscles that normally hold those components of the hip will essentially continue to do their job, but without the painful bone-on-bone contact. Although the cat may have a mechanical lameness and the affected limb may be a little shorter after the operation, the leg will have an almost normal range of motion and excellent function. The animal will be able to sit up, run, jump, and engage in normal cat behavior."