Diseases of the spinal column and cord include congenital defects (discussed earlier in this chapter), degenerative diseases, inflammatory and infectious diseases, tumors, nutritional diseases, injury and trauma, toxic disorders, and vascular diseases.

Degenerative Diseases

Degenerative lumbosacral stenosis is a disorder of the vertebrae in the lower back that causes compression of the nerve roots. It is uncommon in cats (see Brain, Spinal Cord, and Nerve Disorders of Dogs: Degenerative Diseases).

Intervertebral disk disease is a degenerative disease of the spinal column that results in compression of the spinal cord and spinal nerves. It is a common cause of spinal cord disorders in dogs, but rare in cats (see Brain, Spinal Cord, and Nerve Disorders of Dogs: Degenerative Diseases).

Inflammatory and Infectious Diseases

Infectious and inflammatory diseases of the spinal column and spinal cord include bacterial, rickettsial, viral, fungal, protozoal, and parasitic infections. Many of these diseases, such as meningitis and encephalitis, can also affect the brain. Some of the more common infectious and inflammatory diseases that affect the spinal column or cord are discussed below.

Bacterial Diseases

Diskospondylitis is inflammation of the disk between 2 vertebrae (bones in the spinal column). The vertebrae can also be inflamed without infection of the disk. It is rare in cats and is usually due to direct spread of infection from a nearby wound (see Brain, Spinal Cord, and Nerve Disorders of Dogs: Bacterial Diseases).

Viral Diseases

Feline infectious peritonitis is a disease of domestic cats caused by an abnormal immune response to a coronavirus. This condition causes damage to the meninges and to the cells that produce cerebrospinal fluid. Signs of spinal cord inflammation include spinal pain and partial paralysis in 2 or 4 legs. Signs affecting the blood and other organs, especially the eyes, are also common. Available blood tests are unreliable. Analysis of cerebrospinal fluid can be helpful in diagnosis. There is no effective treatment, and the prognosis for recovery is poor.

Myelopathy associated with feline leukemia virus causes nerve damage and affects some cats that have been infected with the feline leukemia virus (see Disorders Affecting Multiple Body Systems of Cats: Feline Leukemia Virus and Related Diseases) for more than 2 years. The main signs are loss of motor control and weakness in the hind legs, which can progress to paraplegic paralysis within a year. Other signs include spinal pain and abnormal behavior. Diagnosis is based on the signs, blood tests, and eliminating other possible causes. There is no treatment.

Rabies (see Brain, Spinal Cord, and Nerve Disorders of Cats: Rabies in Cats) is caused by a viral infection that spreads to the central nervous system from the peripheral nerves. Rabies is common throughout the world except in Japan, and some other islands, including New Zealand, Iceland, and Hawaii. Initial signs are extremely variable, and rabies should be considered a possibility in any unvaccinated animal with severe neurologic dysfunction. Signs that the infection has reached the spinal cord include a loss of motor control and progressive paralysis, usually with a loss of reflexes. Affected animals typically, but not invariably, die within 2 to 7 days of when signs begin. There is no treatment. Vaccination is essential for prevention.

Fungal Diseases

Cryptococcus neoformans is the most common fungus to cause a central nervous system infection in cats. Other fungal organisms may also invade the central nervous system. Infections often affect other organs, such as the lungs, eyes, skin, or bones. Signs of spinal cord infection include partial or total paralysis and spinal pain. Blood or cerebrospinal fluid tests are necessary to diagnose an infection and identify the organism.

Treatment and the outlook for recovery depend on the specific fungus involved. The drug fluconazole is often effective for Cryptococcus infections. Infections with Blastomyces or Histoplasma fungi are difficult to treat, and the outlook for recovery in cats infected with these fungi is uncertain.

Protozoal Diseases

Toxoplasmosis (see Disorders Affecting Multiple Body Systems of Cats: Toxoplasmosis in Cats) is caused by a protozoan called Toxoplasma gondii, which can occasionally cause inflammation of the brain and spinal cord. Infected cats usually have signs of disease in other organs. A blood test or tissue sample can diagnose the infection. Various drugs are recommended for treatment.

Parasitic Diseases

Verminous myelitis is inflammation of the spinal cord caused by a parasite. The most common cause in cats is larvae of Cuterebra flies. Signs of spinal cord inflammation strike suddenly and severely, often affecting one side of the body more than the other, and may progressively worsen over time. This condition is difficult to diagnose except by examination of tissue after death. Drug treatment can be beneficial, but a full recovery is uncertain.

Inflammatory Diseases of Unknown Cause

Feline nonsuppurative meningoencephalomyelitis, also called feline polioencephalomyelitis or staggering disease, is a slowly progressive, inflammatory disease of the central nervous system in domestic cats. It has been reported in North America, Europe, and Australia. The cause is unknown, but a virus or some other infectious agent is probably involved. The disease causes the neurons to degenerate and is most severe in the thoracic segments of the spinal cord. The disease is difficult to diagnosis in a living animal, and there is no treatment, so the outlook is poor. Signs begin with weakness in the legs for 1 to 2 months, followed by sensitivity to touch, head tremors, and changes in behavior.

Tumors

In cats, lymphoma is the most common tumor to affect the spinal cord. Adult cats of any age can be affected. There is a sudden and severe or slowly progressive onset of signs that center around a specific, often painful, tumor on the spinal cord. About 85% of affected cats have positive tests for feline leukemia virus (see Disorders Affecting Multiple Body Systems of Cats: Feline Leukemia Virus and Related Diseases). Treatment consists of combination chemotherapy. Remission is possible, but the longterm outlook is poor.

Nutritional Disorders

Hypervitaminosis A can develop in cats that are fed diets that contain excess vitamin A, such as diets that contain a large amount of liver. Signs include neck pain and rigidity with foreleg lameness. Reducing the amount of vitamin A will prevent further damage but does not reverse the damage that has already occurred.

Injury and Trauma

Spinal cord injuries usually occur as a result of a spinal fracture or dislocation. Common causes in cats include automobile accidents, bite wounds, and gunshot wounds. The injury not only causes initial damage to the spinal cord, but also causes secondary damage from swelling, bleeding, destruction of the nerve sheath, and tissue decay. Signs of spinal trauma typically have a sudden onset, and may progressively worsen. Severe spinal cord injury to the middle or lower back may cause a rigid paralysis, or a limp paralysis that spreads to the entire body over several days and leads to death from respiratory paralysis. Fractured or dislocated vertebrae can often be seen on x-rays. Drug treatment can be helpful if started within the first few hours of injury. Animals with mild neurologic signs from injury often recover after 4 to 6 weeks of cage rest. Surgery is necessary for some types of injuries that cause severe neurologic signs. In cats that have lost the ability to feel pain at locations below the spinal injury, the outlook for recovery is poor.

Poisoning and Toxic Disorders

Delayed organophosphate intoxication can be seen after ingestion or skin contact with insecticides or pesticides that contain organophosphates. In addition to the signs of severe exposure (see Poisoning: Organophosphates), delayed paralysis can develop 1 to 4 weeks after exposure. Partial paralysis of the hind legs worsens progressively and occasionally all 4 legs become paralyzed. A veterinarian will need a history of the cat's possible chemical exposure to make the correct diagnosis. The outlook for recovery is poor for animals with severe signs.

Tetanus is caused by toxins produced by Clostridium tetani bacteria that usually enter the body at the site of a wound. Cats are fairly resistant to tetanus, but cases do sometimes occur. Signs usually develop within 5 to 10 days of infection and include muscle stiffness and rigid leg extension, inability to swallow, protruding eyelids, and locking of the jowl and facial muscles. In severe cases, the animal may be unable to stand as a result of muscle spasms. Treatment consists of wound care, antibiotics to kill any remaining organisms, and tetanus antitoxin. In mild cases, a cat may recover completely with early treatment. In severe cases, death may occur due to respiratory paralysis.

Last full review/revision July 2011 by William B. Thomas, DVM, MS, DACVIM (Neurology); Kyle G. Braund, BVSc, MVSc, PhD, FRCVS, DACVIM (Neurology); Cheryl L. Chrisman, DVM, MS, EDS, DACVIM (Neurology); Caroline N. Hahn, DVM, MSc, PhD, DECEIM, DECVN, MRCVS; Charles M. Hendrix, DVM, PhD; Karen R. Munana, DVM, MS, DACVIM (Neurology); T. Mark Neer, DVM, DACVIM; Charles E. Rupprecht, VMD, MS, PhD; Robert Wylie, BVSc, QDA