Dogs & Parasitic Myelitis

The term myelitis refers to inflammation of the spinal cord. In our canine companions, many conditions can cause this type of inflammation, including the migration of intestinal parasites in the body to the spinal cord itself. This rare, painful condition, known as parasitic myelitis or verminous myelitis, is difficult to properly diagnose.

The most common parasite that causes parasitic myelitis in dogs is Baylisascaris procyonis. This roundworm is usually carried by racoons, according to petMD. Other parasites that can cause verminous myelitis include Spirocerca lupi, Angiostrongylus spp., Dirofilaria immitis, Strongyloides spp. and Halicephalobus spp., according to an article published in the September 2009 issue of the "Journal of Veterinary Diagnostic Investigation." These parasitic roundworms, which are considered nematodes, typically infect a dog's intestines, feeding off the nutrients the dog ingests. These parasites sometimes migrate to a dog's spinal cord through the bloodstream, causing painful inflammation.

If your dog is showing signs of lameness, bring him to the vet for an exam. Inflammation of the spinal cord usually results in limb paralysis -- typically affecting one side of the body more than the other, according to the "Merck Manual for Pet Health." Your vet will examine your pup and take blood tests to determine the cause of spinal inflammation. If the vet finds high levels of white blood cells known as eiosinophils in your pup's blood and abnormal liver enzyme activity, a parasitic infection could be the cause, petMD says. Your vet may also use magnetic resonance imaging to look for lesions on the spinal cord and test your pup's cerebrospinal fluid to look for signs of eiosinophils or parasites.

If your vet suspects a parasitic infection is to blame for your dog's spinal inflammation, she may put him on anti-parasitic medication to rid his body of the parasites. Such medications include fenbendazole, thiabendazole and ivermectin. Hospitalization may also be necessary to stabilize your pup's condition and bring down the inflammation in his spine by administering anti-inflammatory medication, such as steroids. These anti-inflammatory medications also help prevent further spinal inflammation caused when your dog's body reacts to the worms when they begin to die, according to the "Handbook of Veterinary Neurology." The prognosis for this condition is guarded and some dogs may develop permanent paralysis.

Prevent parasitic myelitis by supervising your dog outdoors and keeping him away from the feces of other dogs or wildlife, which may contain the larvae of nematode parasites. Cover your outdoor sandboxes, in which some animals prefer to eliminate, warns petMD. Deworm your puppy at 2, 4, 6 and 8 weeks of age to remove any intestinal worms from his system that he may have gotten from his mother, recommends WebMD. Administer a monthly heartworm preventative medication, which also kills other types of intestinal parasites. This will help eliminate any intestinal worms that he contracts from migrating to his spine or other organs.