Sacrocaudal Dysgenesis in Cats

Sacrocaudal dysgenesis is a condition in which your cat’s spine, back, neck, and nerves may be deformed or missing key areas. This condition tends to be genetic in origin, occurring frequently in tailless breeds such as Manx. Given the importance of the sacral area of your cat’s spine, sacrocaudal dysgenesis can often lead to devastating side effects that interfere with your cat’s normal activities and quality of life. Sacrocaudal dysgenesis is a condition that requires extensive veterinary care and management and has a high rate of mortality in severely affected cats.

Cats suffering from sacrocaudal dysgenesis may display a host of neurological symptoms, primarily focused in the lower half of your cat’s body. While the disease may vary in severity depending on the extent of the degeneration, common symptoms may include:

• Lack of a tail
• Inability to use hind legs completely or in varying degrees
• Hopping bunny-like gait
• Difficulty or inability to defecate
• Difficulty or inability to urinate
• In some cases, rounded lump over affected area of sacrum (area where tail connects to spine)

Sacrocaudal Dysgenesis is typically a genetic condition, appearing at birth in most affected cats. The disease is a result of a malformation of a portion of the spine of your cat called the sacrum. The sacrum is located in the lower portion of your cat’s spine, typically at the origin of where the tail would be. This malformation causes pressure to be applied to nerves in the area and in some cases causes genetic malformation of the nerves themselves at birth. These nerves play vital roles in limb movement and coordination and also send signals to the muscles surrounding your cat’s bowels, allowing them to defecate. 

While the condition occurs mainly in tailless cats, not all cats without tails will be affected. Sacrocaudal dysgenesis occurs when the gene that causes taillessness does not completely express and also causes a malformation of the sacrocaudal nerve. Sacrocaudal dysgenesis is known to be an autosomal dominant trait in Manx cats. This means that if a cat carries the gene for the disease, they will display some characteristics or symptoms. In order to prevent the continuation, affected cats should be removed from breeding programs. 

In most cats, sacrocaudal dysgenesis will appear at birth or shortly thereafter. In very young or growing cats, symptoms may be minor or may gain in severity as the kitten grows and more strain is put on the nerves and support structure in the spine. Diagnosis of this condition will occur in your veterinarian’s office where they will attempt to rule out other conditions with similar symptoms. The lack of a tail in combination with the symptoms is typically definitive. 

In some cases, your vet may wish to order imaging tests in order to determine the extent of the deformity. These may include x-rays or MRIs which will give a detailed picture of the skeletal and spinal structure of your cat. Normally, your cat will not need to undergo anesthesia for an x-ray, however, a mild sedative may be necessary to keep your cat as still as possible. Most cats will need anesthesia in order to perform an MRI, given that it requires the maximum amount of stillness and restraints cannot be used.

There is currently no known cure for sacrocaudal dysgenesis. In affected cats, the condition is permanent. In cats that are mildly affected, symptoms will typically worsen with age and degeneration of the surrounding nerve. Treatment will therefore focus on maximizing the quality of life for affected animals.

Depending on the severity of symptoms, your vet may be able to prescribe therapeutic treatment to help your cat lead as normal a life as possible. Certain medications can help your cat relieve the bowels and experienced owners can be taught how to manipulate your cat’s bladder to aid in urination. For pets with problems moving, mobility devices such as modified slings or hind leg chairs with wheels may be a useful tool to help your cat get around.

Prognosis for recovery in cats with sacrocaudal dysgenesis is typically very poor. Mild cases with only a minimal level of symptoms may be managed with various supportive treatment options, but your affected cat will need therapeutic assistance throughout their entire life. In severe cases, pet owners should speak with their vets regarding options for humane euthanasia. While these can be difficult decisions, owners should weigh their ability to support an affected animal with the financial costs and pain and discomfort experienced by the cat as a result of the condition.