Hip dysplasia is an orthopedic condition of the hip joint that, though uncommon, can affect cats. It results from abnormal development of one or both hip joints and causes instability and degeneration of the joints. Cats don't always exhibit clear signs of hip dysplasia, but symptoms such as limping, avoiding exercise, and irritability may point to a diagnosis. Hip dysplasia in cats is mainly hereditary but can sometimes be caused by obesity. Large purebred cats such as Maine coon and Himalayan cats are more likely to develop hip dysplasia than mixed breed cats. Treatment typically involves medications to manage pain and inflammation. If detected and treated early, you can expect a full recovery.

What Is Hip Dysplasia?

Hip dysplasia is a degenerative disease that causes a malformation of the ball-and-socket joint in the hip, leading to pain and stiffness. Cats with hip dysplasia will likely develop osteoarthritis if the disease progresses.

A normal, functioning hip joint consists of a rounded femoral head that sits in a socket-like structure called the acetabulum. The joint can operate smoothly with the assistance of cartilage, joint fluid, and muscles. But when a cat has hip dysplasia, the femoral head develops an irregular shape and does not sit properly within the socket. The joint becomes unstable, causing pain, inflammation, and stiffness. The poorly-fitting joint may eventually erode the cartilage, causing the bones to rub together.

Symptoms of Hip Dysplasia in Cats

It is common for cats to show no signs of illness in the early stages of hip dysplasia, and cats with mild to moderate disease may never exhibit symptoms. Your vet may discover signs of hip dysplasia during a routine wellness exam or when taking x-rays for an unrelated reason.

The signs of hip dysplasia may be similar to other injuries. If you see these or any other signs of illness in your cat, contact your vet for an appointment.

Symptoms may include:

Lameness or Limping

The pain, inflammation, and stiffness caused by your cat's unstable joint may lead to lameness or limping. If untreated, this will likely get worse over time. If you notice changes in your cat's mobility, consult a vet.

Exercise Intolerance

In addition to lameness and limping, hip dysplasia can affect your cat's ability to exercise, impacting movements like jumping, running, and climbing.

Lethargy/Irritability

If your cat has hip dysplasia, it might be experiencing lethargy and irritability due to the pain of the condition. If you notice a change in your cat's mood, consider physical discomfort a potential cause.

Stiffness

Your cat's poorly-fitting joint may lead to stiffness. The stiffness may be especially noticeable when your cat gets up or lies down.

Muscle Loss

Muscle loss in your cat's hips or thighs may be symptomatic of hip dysplasia. Conversely, enlarged shoulder muscles can also be a sign of hip dysplasia, as your cat is relying more on the top half of its body to avoid painful use of the hips and compensate for the muscle loss.

What Causes Hip Dysplasia in Cats?

Hip dysplasia is believed to be a hereditary disease in cats, but a couple of factors can be linked to the development of the condition.

Obesity

Your cat's weight can contribute to the development of hip dysplasia, as excess weight increases the amount of pressure put on a cat's hips, eventually leading to joint distress.

Injury

If your cat has been injured in the past, such as having been hit by a car, the strength of its hips may be compromised, making the development of a joint condition more likely.

How Do Vets Diagnose Hip Dysplasia in Cats?

If you suspect your cat has hip dysplasia, it's best to visit your vet to confirm the issue. After observing symptoms of hip dysplasia in your cat, your vet can give a formal diagnosis following an x-ray of the affected joint.

How to Treat Hip Dysplasia

Your vet will diagnose your cat's hip dysplasia through a physical examination and x-rays. Treatment considerations are made based on the severity of the x-ray results and your cat's symptoms.

Hip dysplasia in cats is typically first treated conservatively. This treatment generally includes medications to manage pain and inflammation and possible changes in activity levels. If the conservative approach is not enough, your vet will talk to you about surgical treatment for your cat.

The most common surgery is called a femoral head and neck excision. During this surgery, the vet removes the deformed head and neck of the femur. In time, your cat's muscles rebuild and form a new, false joint. After recovery, most cats will live a happy, normal life.

In rare cases, your vet may consider a total hip replacement. This surgery involves the replacement of the hip joint with a special synthetic hip called a micro-THR.

Prognosis for Cats with Hip Dysplasia

If detected early and treated swiftly, you can limit the residual effects of hip dysplasia in your cat. As the impact of the condition progresses, symptoms will appear gradually and continue to worsen over time if unnoticed or untreated. For example, osteoarthritis typically occurs secondary to hip dysplasia, making the pain, inflammation, and stiffness worse. Severe hip dysplasia often requires surgery, but usually, treatment will fully rehabilitate your cat. If surgery isn't suitable for your cat, your vet may prescribe anti-inflammatory medication or physical therapies.

How to Prevent Hip Dysplasia

Because it is hereditary, hip dysplasia in cats cannot be completely prevented. But you may be able to catch the condition early and slow its progression. If your cat is not genetically predisposed to hip dysplasia, the best preventative measure is to make sure that your cat is a healthy weight and exercises its muscles frequently. Contact your vet when you first notice ongoing lameness, pain, or stiffness.

Future cases of hip dysplasia can be prevented by cat breeders in that a cat with hip dysplasia can be spayed or neutered to discontinue the genetic passage of the condition. Cats with hip dysplasia should not be used for breeding.