What is Spina Bifida?
In addition to obvious malformation of the spine, incontinence and partial paralysis of the back legs are also common symptoms of spina bifida. Manx cats are especially genetically prone to spina bifida as they are carriers of the gene that causes this condition.
Spina bifida is a neurological developmental abnormality in cats and other animals characterized by improper growth and formation of vertebral arches. This defect leaves a gap or cleft in the spine and the spinal cord is partially or completely exposed. This condition is usually obvious in young animals due to malformation of the spine or difficulty with locomotion, however, spina bifida in cats can be subclinical or symptomless and only discovered incidentally to treatment of another condition. The malformation usually affects the lower or lumbar region of the spine although it can manifest higher up on the spine.
Symptoms of Spina Bifida in Cats
Although spina bifida can be symptomless, it usually manifests in a kitten when they begin to walk or when a young cat experiences a growth spurt. The following symptoms may occur:
- Obvious malformation of the spine - cavity or swelling can be felt or there is dimpling of the skin where malformation occurs
- Limping, specifically a hopping gait in back legs
- Weakness in back legs, unsteady gait
- Urinary incontinence
- Fecal incontinence
- Neurological signs, such as seizure or paralysis
- Buildup of fluid in spine resulting in swelling and infection
It should also be noted that spina bifida tends to manifest in tailless cats (Manx breed) which have a condition known as sacrocaudal dysgenesis (stumped tail). The gene mutation that causes taillessness is associated with spinal malformations such as spina bifida.
There are several different types and terms which may be used by your veterinarian to describe spina bifida which are specific to the character and cause of the condition.
- Sacrocaudal dysgenesis: shortened spine producing taillessness in cats
- Spina bifida occulta: a subclinical condition with incomplete formation of vertebral arches
- Spina bifida manifesta: describes spina bifida that results in central nervous system symptoms
- Spina bifida cystic: occurs when there is herniation of the membrane covering the spinal cord, usually resulting in severe symptoms (Meningomyelocele).
- Spina bifida aperta: characterized by a gap in the vertebra which allows the spinal cord to be exposed to the skin surface.
- Meningeal dysplasia: used to describe the condition when the tissue around the spinal chord forms abnormally
- Spinal cord dysplasia: describes a malformed spinal cord
Causes of Spina Bifida in Cats
Spina Bifida is a genetic malformation of the vertebral arches in the spine. This malformation of the spine may be caused by:
- A dominant autosomal gene present in Manx cats (sacrocaudal dysgenesis)
- Mutation or damage to a gene of a non-tailless cat
- Exposure to toxins in pregnant queens or nutritional deficiency may also play a role
Diagnosis of Spina Bifida in Cats
Spina bifida will be diagnosed by your veterinarian based on a physical examination and x-rays, specifically myelography, a procedure in which a substance is injected into the spine that allows defects of the spine to be more easily seen on the x-ray. In addition, computed tomography (CT) and magnetic resonance imaging (MRI) can provide more information on spinal malformations and their effect on your pet’s functioning. Any information you can provide as a pet owner on your pets breeding, specifically any tailless cats in their heritage, would be helpful.
Treatment of Spina Bifida in Cats
If the condition is asymptomatic (subclinical) treatment is not required.
When symptoms of spinal malformation are present, in certain cases, your veterinarian may be able to surgically intervene to improve the cat's condition. Example of this are when a tethered spinal cord manifests or when a gap in the spine can be covered by tissue. Physical therapy may be useful in cases which surgical intervention was possible.
Usually, prognosis is poor for cats that manifest severe symptoms of this condition and euthanasia may be required. Cats with milder manifestations can be treated for their symptoms and will require frequent veterinarian monitoring. If infection is present, antibiotics may be prescribed.
Recovery of Spina Bifida in Cats
If your cat has been diagnosed with subclinical spina bifida (no symptoms) then no special care is required, but you should be vigilant as your cat ages for the appearance of any signs of the condition. There is no cure for spina bifida, and only management of symptoms is possible. Pet owners with a cat that has clinical spina bifida (symptoms present) may have to deal with chronic urinary and fecal incontinence, constipation, or urinary tract infections as well as the manifestation of neurological symptoms if infection or complications arise in the spinal cord. A pet with this condition will require frequent trips to your veterinarian to address issues. Constipation can be treated with stool softeners and an appropriate diet. Occasional treatment with antibiotics for secondary infections due to incontinence or complications arising from spinal column malformation may be necessary. Cats with spina bifida have shorter expected life spans due to complications. It will be recommended that cats with the clinical or subclinical condition be removed from any breeding program.