Infections by virus, bacteria, rickettsia or protozoa may cause inflammation of spinal cord and the spinal column in dogs. Parasitic infestations and fungal spores can also irritate the nerve tissue. Encephalitis (inflammation of the brain), as well as meningitis (inflammation of the meninges that cover the brain and the spinal cord), are inflammatory conditions affecting parts of the central nervous system.
A few of the inflammatory disorders involving the spinal cord and the spinal column are explained here.
Diskospondylitis in Dogs
This inflammatory condition of the spinal cord occurs when the cartilage disks separating the spinal column bones, or vertebrae, develop bacterial infections. Even though inflammation of the disks can occur in the absence of infections, bacterial infections in the blood spreading to the spinal column is the most common reason. Immune system deficiencies may further facilitate the development of such infections.
Diskospondylitis is more prevalent in larger breeds of dogs. The main symptom is spinal pain, but sometimes it may be accompanied fever and weight loss. The dog may appear depressed. The neurologic symptoms are usually brought about by the pressure exerted on the spinal cord by the swelling of the inflamed tissues. Occasionally, the bacterial infection may spread to the spinal cord too. Testing the urine and the blood may help detect the infection. Antibiotic therapy is effective in treating most bacterial infections, and the symptoms may get resolved within a few days of initiating treatment. However, the medications may have to be used for 2 more months to completely eliminate the bacteria from the spinal column, and to prevent recurrence.
Rickettsial Diseases In Dogs
Rickettsial infections in dogs may result in spinal cord disorders. Typical examples are ehrlichiosis and Rocky Mountain spotted fever which cause large-scale inflammation of the spinal cord.
The infection can be detected by testing the blood as well as the cerebrospinal fluid. If prompt antibiotic treatment is given, the dog may recover completely from the infection. The medication is usually continued for a minimum of 2-3 weeks. However, some neurologic symptoms may persist or even become worse, in spite of successfully eliminating the infection.
Canine distemper encephalomyelitis
Inflammation of the brain and the spinal cord is the main effect of this viral infection. Canine distemper is the most common disorder of the central nervous system. Dogs all over the world are affected by this scourge. The symptoms of neurologic involvement usually appear all of a sudden, but the progress of the disease is slow, but steady, and often depends on the site of inflammation.
Fever accompanied by pain is usually the first symptom of canine distemper in adult dogs. Loss of motor control, often leading to paralysis, may follow. Blood tests are not of much use in diagnosing this viral infection. Since there are no effective treatments for distemper, dogs with severe forms of the disease often succumb to it. Necropsy may be done afterwards to confirm the disease. Prevention of the infection by vaccination is the best option.
This is an extremely serious and fatal viral infection that is spread through the bite of an infected animal. The infection starts in the peripheral nerves and spreads to the brain. Rabies is prevalent in most parts of the world, except in a few countries such as Japan, New Zealand, Hawaii and Iceland. The early symptoms are not conclusive; hence any animal that is not vaccinated against rabies should be treated with suspicion as a potential carrier of the disease, if it shows symptoms of neurologic dysfunction.
When the spinal cord gets affected, the dog may have loss of motor control and reflexes which eventually leads to paralysis, and finally to death within a week to 10 days of contracting the disease. Vaccination is the only option to prevent rabies, as there is no treatment once the animal is infected. The very high risk of this fatal infection spreading to other animals and people is a grave concern too.
The fungal infection that affects the nervous system of dogs most frequently is caused by Cryptococcus neoformans. Several other fungi may also cause inflammatory disorders involving the nervous system as well as other internal organs, but some may cause only localized infection in the skin or eyes. Involvement of spinal cord results in neurologic symptoms such as spinal pain and paralysis. Blood tests, as well as testing of the cerebrospinal fluid, can help detect fungal infections and identify the species causing them.
There are many anti-fungal medications to treat fungal infections; but the prognosis greatly depends on the type of fungus that has caused the infection. There are a few stubborn species that are difficult to eradicate. For example, Histoplasma infections are notoriously difficult to treat, so is Blastomyces. On the other hand, Cryptococcus infections respond well to the anti-fungal drug fluconazole.
The protozoan Neospora caninum is responsible for neosporosis in dogs, characterized by brain and spinal cord inflammation. It may affect young dogs and puppies, causing rigid paralysis in the hind limbs. One or both the limbs may be involved. It can also affect internal organs such the lungs and the liver, in addition to the muscle tissue. The disease is detected by testing the blood and a sample of the tissue. Even though treating the disease early with appropriate drugs may help resolve the problem, it may not guarantee complete recovery.
Protozoan infection by Toxoplasma gondii is the cause of this disease.Brain and spinal cord inflammation can sometimes occur as a result of toxoplasmosis, but it generally occurs in association with other bacterial or viral infections. For example, canine distemper is usually found in dogs which have toxoplasmosis. Testing the blood or sample of the tissue can detect the disease. It can be treated with a number of drugs.
Spinal cord Disorders due to Parasitic Diseases
Parasitic infestations may irritate the nerve tissues and inflame the spinal cord, resulting in a condition referred to as verminous myelitis. An intestinal parasite named Baylisascaris procy-onis (dog roundworm) usually causes this type of myelitis. The symptoms resulting from the inflammation of the spinal cord may appear suddenly, with one side of the body affected more. It progresses rapidly, often culminating in the death of the dog, even though drug therapy may be effective in some cases. But diagnosis is not easy, and it is usually the post-mortem tests that reveal the cause of death.
Inflammatory Diseases of Unknown Cause affecting the Spinal cord
Inflammation of the spinal cord or the meninges may occur due to many known factors, but in many cases, the exact cause cannot be determined.
It is an inflammatory condition found in dogs all over the world, but the cause is not identified even though certain viral infections are implicated. It may appear in two forms, but both display similar symptoms, such as pain in the neck and paralysis of the limbs.
This central nervous system disease may affect adult dogs of any breed, but it’s more prevalent in the smaller breeds, particularly Poodles. Female dogs are found to be more susceptible to this condition for some reason. Once the symptoms begin to appear, the progress of the disease may take a few months. Testing of the cerebrospinal fluid may help diagnose it. Even though temporary improvement is possible with drug therapy, its success, especially in the long-term, cannot be guaranteed.