Verminous myelitis in dogs is a neurological disorder resulting from parasitic infections in the spinal cord. Although relatively rare, it can severely impact a dog’s health and mobility. The term “verminous” refers to the involvement of worms or worm-like parasites, which invade the spinal cord and trigger inflammation, known as myelitis. This condition can be caused by different parasites, and its occurrence largely depends on geographic location and a dog’s exposure to these parasites.

Here’s what you should know about the symptoms, causes, and treatments for the condition in dogs.

Symptoms of verminous myelitis in dogs

Verminous myelitis often presents itself with subtle signs that may initially be mistaken for less severe health issues. However, as it progresses, it can cause significant discomfort and mobility issues for affected dogs. Common symptoms include:

• Weakness or paralysis, often asymmetrical
• Lack of coordination (ataxia)
• Inability to walk
• Pain or sensitivity along the spine
• Muscle wasting or loss of muscle control
• Behavioral changes due to discomfort
• Difficulty with bladder or bowel control

The onset of symptoms typically occurs within a few weeks after exposure to the parasite, but this can vary based on the type of parasite and the dog’s overall health and immune response. It’s important to note that without prompt veterinary intervention, the condition can quickly worsen, leading to more severe neurological deficits and potentially life-threatening complications. As a result, if you suspect your dog is showing any symptoms of verminous myelitis, take them to a veterinarian immediately for a proper diagnosis and appropriate treatment plan.

To diagnose verminous myelitis, your veterinarian will likely begin with a thorough physical examination and review of your dog’s medical history. They might recommend blood tests to identify signs of infection or inflammation and imaging techniques like MRI or CT scans to get a detailed view of the spinal cord. In some cases, a cerebrospinal fluid (CSF) analysis may be necessary to detect the presence of parasites or related immune responses. That said, however, this condition is notoriously difficult to diagnose, and in many cases, a definitive diagnosis is only possible through post-mortem tissue examination.

Causes of verminous myelitis in dogs

In dogs, the main cause of verminous myelitis is parasitic infections, particularly those involving nematodes or roundworms. The most common parasites responsible for this condition are:

• Baylisascaris procyonis: This is a roundworm found in raccoons, which are its natural hosts. Dogs can become infected by ingesting eggs from raccoon feces or contaminated environments.
• Angiostrongylus vasorum: Also called the French heartworm, this parasite typically targets the lungs and blood vessels. However, in some cases, it can reach the spinal cord and trigger neurological issues.
• Toxocara canis: While mainly affecting the gastrointestinal tract, the larvae of this roundworm can migrate to the central nervous system, causing inflammation and, in severe cases, myelitis.
• Dirofilaria immitis: Better known as the heartworm, this parasite usually infects the heart and lungs. In rare instances, it can cause myelitis through aberrant migration.

Once these parasites enter the central nervous system, they elicit an immune response that leads to inflammation and swelling. This reaction disrupts normal neural function and damages nerve tissues. As the body continues to fight the parasites, the prolonged inflammation can result in significant neurological damage. Over time, this damage manifests as symptoms like paralysis, weakness, and loss of coordination in affected dogs.

Several factors can increase a dog’s risk of developing verminous myelitis. Geographic location is particularly important, as areas with a higher prevalence of certain parasites pose a greater threat. Dogs who spend a lot of time outdoors, especially in environments where they may encounter intermediate hosts such as snails, slugs, or mosquitoes, are more likely to be exposed. Additionally, lack of regular veterinary care and parasite prevention measures can contribute to the development of this condition. Puppies and young dogs are also more susceptible due to their immature immune systems.

Treatments for verminous myelitis in dogs

The treatment of verminous myelitis in dogs focuses on both addressing the parasitic infection and managing the neurological symptoms. This can involve:

• Antiparasitic medications: These drugs target the parasites directly and help eliminate the underlying cause of the myelitis. Your veterinarian will prescribe the appropriate medication based on the specific parasite involved. Common antiparasitic medications include ivermectin, fenbendazole, or milbemycin oxime.
• Anti-inflammatory drugs: To reduce inflammation and alleviate pain, your vet may recommend anti-inflammatory medications. These can help improve your dog’s comfort and mobility during recovery.
• Supportive care: Depending on the severity of the condition, supportive care such as fluid therapy, nutritional support, and physical therapy might be necessary.
• Regular monitoring: Frequent check-ups with your vet are crucial to monitor your dog’s progress and adjust the treatment plan as needed. This is essential for ensuring effective management of the condition and facilitating early intervention should any complications arise.

With the right treatment and care, many dogs with verminous myelitis can recover and return to normal activities, although some may experience residual neurological deficits. However, if the infection has caused significant damage to the spinal cord before treatment begins, the chances of full recovery can be lower. Ultimately, the best way to improve your dog’s outcome is through prompt veterinary care and strict adherence to the prescribed treatment plan.

Not to mention, once your dog has recovered, you’ll want to focus on prevention to avoid future infections. This may include implementing a regular deworming schedule, using appropriate parasite prevention medications, and ensuring your dog avoids high-risk environments. Moreover, maintaining good hygiene practices — such as cleaning up feces immediately and keeping your dog’s living area clean — can further reduce the risk of reinfection.