There are three different types of deformation that can happen to the spine. The first is scoliosis, an issue in which the spine is curved to the side when looking down at the cat. The second is kyphosis, which manifests as a hunch or lump in the cat’s spine. Lordosis is the final variation, in which the spine curves down in a “u” shape. Multiple deformities may be present at once. 

Sometimes the vertebrae are misshaped and wedge-like, which can lead to neurological problems because of spinal cord pressure. Block vertebrae (or fused vertebrae) can also occur, limiting the cat’s flexibility. Spinal defects are commonly paired with thoracic wall and sternum deformities.

The spine of a cat is made up of 30 vertebrae with discs of cartilage in between each bone section to absorb impact. Cats also have a floating collarbone, which helps them to be extremely flexible. When problems happen during fetal development, deformities of the spine and its connected bones may occur. These defects are relatively common in cats, and can be noticed in affected young kittens.

Because most cases of spinal defect are not severe, many cats with mild spine defects experience no pain and little discomfort. Serious symptoms can arise in extreme instances of birth defects. Symptoms to watch for include:

Birth defects form while the fetus is developing in its mother's womb. Any cat with spinal defects should be sterilized to ensure that said defects are not passed on. Queens that have multiple kittens with spinal defects should also be spayed. Potential causes include:

Often, you will notice spinal defects in a cat’s first few weeks of life. Take your cat to a veterinarian immediately if symptoms are severe. Once at a veterinary clinic, the vet will perform a complete physical examination of the cat. Just feeling the spine can help determine what defects are present. If the case is extreme, you may be referred to a veterinary orthopedic specialist for further testing. 

X-rays will need to be taken from above and from each side to identify the exact angle of the curve in the spine. An X-ray can also show any associated sternum defects. If necessary, surgery will be planned based on radiograph images. The cat will need to undergo a pre-anesthetic health check to make sure it is fit for surgery. A blood-gas analysis may be used to see how much oxygen and carbon dioxide are in the blood if associated cardiac issues are present.

Many cats learn to adapt to their spinal deformities. Surgery should only be chosen as a last resort attempt to offer a severely deformed cat some quality of life. Surgery of the spine is always risky, however, risk is increased when the recipient is a kitten. 

Over time, physical therapy can help a cat learn how to restore movement to affected body parts. Stretches and extension exercises can help with this. The cat may also need to go through balance training to learn how to compensate for spinal defects. Hydrotherapy has also been proven to help cats gain more mobility when a spinal deformity exists. 

If deemed absolutely necessary, a surgery to correct the alignment of the spine may be performed. During surgery, the chest cavity may be expanded and sternum deformities may be corrected. This is usually done by implanting a splint externally and attaching the sternum to it using sutures. The splint will remain attached for 10-21 days. The best time to correct spinal defects is when a kitten is approximately two weeks old. Older cats can also undergo corrective surgery, however, a sternectomy (removal or partial removal of the sternum) may be the only surgical option at that time. 

If the cat has undergone surgery, you will need to monitor it closely for any suture abscesses, dermatitis or abrasions that may develop. The splint will need to be adjusted as the kitten grows. Multiple veterinary check ups will be needed during recovery. Spinal surgery carries many complications and is not always survived. 

If a cat has only a mild defect, having a few X-rays taken each year can help monitor the progression of spine curving. Many cats live long and normal lives with spinal deformities. Even permanently disabled cats tend to function well and learn how to accommodate their limitations. Extreme cases may require euthanasia if surgery is not an option and the cat's quality of life is significantly damaged.