Feline Osteochondrodysplasia: Symptoms, Diagnosis, and Treatment Explained in Detail by a Veterinarian

Osteochondrodysplasia is a hereditary joint disease that primarily affects Scottish Folds. In severe cases, the joints swell like lumps, causing difficulty walking and pain.

In this article, we will explain the symptoms, diagnosis, and treatment of feline osteochondrodysplasia in detail.

What is Osteochondrodysplasia?

Osteochondrodysplasia is a hereditary joint disease that causes abnormal gait, pain, and joint deformities.

About Osteochondrodysplasia

Osteochondrodysplasia is a disease that causes abnormalities in a cat's cartilage and bones. Cats with this condition develop abnormalities in the joint cartilage, leading to lump-like swellings in the joints (osteochondromas), which cause difficulty walking and pain. In addition to osteochondromas, deformities can also occur in the tail. This disease is progressive, and the lumps and deformities gradually worsen as the cat grows.

Genetic Factors and Risk of Development

Osteochondrodysplasia is caused by genetic abnormalities. The breed most prone to this disease is the Scottish Fold, where their characteristic folded ears are linked to the condition.

To explain the genetics: parents typically have a pair of two genes; these split into individual genes in sperm and eggs, then pair up with the partner's gene upon fertilization.

Folded ears are a "dominant trait," meaning the trait appears if even one abnormal gene is inherited from a parent. If a parent cat has folded ears, the kittens will inevitably be born with folded ears. Because osteochondrodysplasia affects cartilage, Scottish Folds with folded ears are potentially affected by the disease, though the severity of symptoms varies.

In particular, when two folded-ear cats are bred together, the kittens tend to exhibit more severe joint abnormalities. Scottish Folds that do not have folded ears are less likely to have the disease, or if they do, the symptoms tend to be milder.

Because it is a hereditary disease, it manifests from a young age and progresses gradually.

While particularly well-known in Scottish Folds, American Curls, Himalayans, Persians, and Munchkins are also said to be prone to this condition.

Symptoms and Diagnostic Methods for Osteochondrodysplasia

Symptoms of Osteochondrodysplasia

A characteristic symptom of osteochondrodysplasia is the formation of lumps called osteochondromas on the wrist and ankle joints. Because the joints become fixed, the cat develops an awkward gait. The lumps can be felt by touch. Deformities can occur not only in the hand and foot joints but also in the tail; however, abnormalities do not typically occur in the elbows, shoulders, knees, or hip joints.

Symptoms include an awkward walk or dragging of the limbs. If the osteochondromas are large, they may make a clicking sound when the cat walks. Because osteochondrodysplasia is painful, affected cats may become less active, showing reluctance to move or jump. They may also show extreme dislike for having their nails trimmed.

The sitting posture often seen in Scottish Folds, where they stretch out their hind legs, is called the "Scottish Fold sit," which is thought to be a way of sitting that reduces strain on their deformed ankles.

Diagnostic Methods

Diagnosis at a veterinary clinic begins with an interview, visual examination, and physical palpation. Subsequently, an X-ray examination is performed to take images of the hands, feet, and tail to confirm the diagnosis.

X-rays of cats with osteochondrodysplasia reveal characteristic osteochondromas and joint deformities in the hands and feet.

Since cats often remain still in the examination room, taking a video of your cat's walking or jumping at home can be helpful for diagnosis.

Treatment and Care for Osteochondrodysplasia

Osteochondrodysplasia is a hereditary disease, and no cure has been found in modern veterinary medicine. Therefore, pain management is the primary form of treatment.

Anti-inflammatory Analgesics and Supplements

As osteochondrodysplasia causes progressive deformation of the cartilage and joints, there is no curative treatment, and symptomatic treatment to manage pain is the primary approach. Pain management using anti-inflammatory analgesics and the use of supplements to protect joints and reduce pain are standard. Most treatments involve oral medications, but injectable drugs for arthritis may also be used.

Radiation Therapy

In severe cases where large osteochondromas have formed, radiation therapy is considered to show improvement. Facilities capable of providing radiation therapy are limited to secondary medical institutions such as university hospitals, and the procedure is performed under general anesthesia. Therefore, the cost of treatment is high.

Surgery

Arthritis may lead to the formation of bone spurs, known as osteophytes, which can cause intense pain. Surgery to remove these spurs may be performed, but its goal is merely the temporary alleviation of symptoms.

Care for Osteochondrodysplasia

Cats with osteochondrodysplasia are not only unable to move around and jump properly but also suffer from pain. Therefore, improving quality of life (QOL) through early detection and early treatment is key.

At home, you might consider installing ramps in areas with stairs to avoid putting strain on their joints. Since they may find it difficult to step over the edges of litter boxes, switching to a box with a lower entrance is also important. Ensure that water and food are placed within the cat's easily accessible range.

Weight gain increases the burden on the joints. It is important to control food intake to avoid excessive calories.

Points for Early Detection

Because osteochondrodysplasia is a hereditary disease, there is no way to prevent it. Currently, it is recommended not to breed two folded-ear Scottish Folds together, but any Scottish Fold with folded ears is at high risk of developing the disease. If you own a breed known to be prone to this, such as a Scottish Fold, Munchkin, Persian, or Chinchilla, it is important to keep in mind that they may develop osteochondrodysplasia.

Since there is no cure, treatment primarily focuses on managing symptoms as they appear. By the time symptoms are noticeable, the pain may already be severe, so early detection and early relief of that pain can lead to a better QOL.

To achieve this, ensure your cat has regular check-ups at a veterinary clinic starting from kittenhood to monitor their weight and joint movement. It is also important to have X-rays of the limb joints taken once the cat is over a year old to diagnose any joint abnormalities as early as possible.

Summary

Osteochondrodysplasia is a hereditary disease for which there is no prevention or cure. It is stressful for cats as it causes pain and makes it difficult for them to move. If you own a prone breed such as a Scottish Fold, make sure they receive regular check-ups to free them from pain as early as possible.