Coonhound Paralysis: What You Need to Know

Coonhound paralysis, or acute polyradiculoneuritis, is a potentially severe neurological disorder that can affect any dog breed. Originating from exposure to raccoon saliva, yet occasionally occurring without this contact, this disease triggers the dog's immune system to damage its nerve's protective coating, leading to symptoms like a stiff gait, slow reflexes, and weakened vocal ability, with severe cases resulting in paralysis. While rare and distressing, most dogs can fully recover with appropriate care, including keeping them comfortable and monitoring their breathing. In this article, our veterinarians will discuss in more detail the causes, symptoms, diagnostic tests, treatments and prognosis for coonhound paralysis.

What causes coonhound paralysis?

Coonhound paralysis, or acute polyradiculoneuritis is caused by an immune response in dogs to a specific substance found in raccoon saliva. This reaction can lead to neurological symptoms, which typically appear in some dogs within 7 to 14 days of coming into contact with the saliva of a raccoon.

Acute polyradiculoneuritis is the most frequently encountered type of peripheral nerve disorder in dogs. It is commonly observed that hunting hounds, especially coonhounds, are more susceptible to this issue in North America. However, in countries where raccoons are not found, like in the UK, canine breeds such as Jack Russell and West Highland White Terrier are more often affected.

In cases where the has been no recent exposure to raccoon saliva, veterinarians call this idiopathic acute polyradiculoneuritis. This condition shows similar clinical and histopathologic features and seems to be caused by an immune system issue, although the exact cause is not known. However, it is possible that infections from Campylobacter and Toxoplasma may play a role.

Interestingly, coonhound paralysis closely resembles the human disease, Guillain-Barré Syndrome (GBS). This rare neuromuscular disorder is when the immune system mistakenly targets the nerves in people.

What are the symptoms of coonhound paralysis?

If you're an observant dog owner, you might first notice your dog walking stiffly or clumsily, especially with their back legs. This can quickly progress to a condition where they're weak and can barely move all four limbs - this usually happens within 10 days of when you first noticed something was off. Their usual reflexes might be weaker or gone completely, except for their ability to pull their paw back if you pinch their toe - but even that might be weak.

This weakness usually starts in the back legs and moves up to the front legs, neck, and head. The worst of it typically happens about 10 days after the first signs. Your dog's muscles might start to get smaller and weaker as soon as 3-5 days after they start showing signs of weakness or paralysis.

Dogs may experience nerve issues in their face, resulting in changes to their bark, difficulty swallowing, or facial paralysis. Additionally, some dogs with coonhound paralysis may be hypersensitive to touch or experience mild pain when their toes are pinched. In severe cases, muscle weakness or paralysis between the ribs can make breathing difficult and even result in loss of breath.

How is coonhound paralysis diagnosed?

Determining if your dog has this condition relies on several factors. Your veterinarian will review your dog's health history, symptoms, and physical examination results. Additionally, they will start to exclude other possible reasons that might explain the symptoms that are present. Unfortunately, there is no confirmatory test available to diagnose coonhound paralysis.

If there has been a recent history of exposure to a raccoon and there are neurological symptoms present, this would be highly suspicious of coonhound paralysis.

The key sign of coonhound paralysis in dogs is a sudden weakness or even paralysis affecting all four legs. This usually happens within 10 days of when you first notice something's not quite right with your dog. Their reflexes might be weaker or gone altogether. Your dog's muscles might also seem less firm than usual.

This weakness typically starts in the back legs and moves up to the front legs, neck, and head. Some dogs might also have trouble breathing.

What is the treatment for coonhound paralysis?

Unfortunately, there's no known specific therapy for coonhound paralysis, so the focus is on giving supportive care to manage the symptoms.

Caring for a dog with this condition requires ensuring their comfort and assisting them with routine activities. It's important to provide a soft, clean, and dry resting area to prevent the development of sores due to prolonged lying in one position.

Assisting your dog with eating, drinking, and elimination may also be necessary. If your dog is unable to urinate independently, you or your veterinarian may need to apply gentle pressure to their bladder or utilize a catheter.

To maintain lung health, aim to gently shift your dog's position from one side to the other every four hours. Engaging your dog in physical therapy, such as aquatic exercises, can help keep them clean and prevent muscle deterioration.

If your dog experiences difficulty breathing, it may require mechanical assistance for proper respiration. Some dogs may also need a feeding tube to ensure adequate nutrient intake. It is also important to handle your dog gently and calmly, especially if they are sensitive to touch.

What is the prognosis for dogs with coonhound paralysis?

Affected dogs will spontaneously improve within 2-3 weeks and most will have a complete recovery within 2-4 months. It is important to provide adequate supportive care for your dog throughout their recovery.

Some dogs however can have a delayed recovery where symptoms of coonhound paralysis persist for 6 or more months. Dogs that require assisted ventilation, have aspiration pneumonia and/or severe muscle atrophy negatively affect the prognosis.

It is possible for relapses to happen, particularly in hunting dogs that come across raccoons often. If a hunting dog has recovered from coonhound paralysis or acute polyradiculoneuritis, it's advised not to use them again for raccoon hunting. For non-hunting dogs, recurrences are very uncommon.

In conclusion, coonhound paralysis is a neurological issue affecting dogs, particularly in North America. It’s closely related to Guillain-Barré Syndrome (GBS) which affects humans and can cause weakness or even paralysis of all four limbs. Symptoms of coonhound paralysis may include walking stiffly or clumsily, weak reflexes, facial changes such as difficulty swallowing or barking differently, pain when the toes are pinched, muscle atrophy and breathing difficulties. Treatment for coonhound paralysis involves supportive care such as ensuring comfort and assisting with routine activities like eating and urinating. Most affected dogs will have a complete recovery within 2-4 months; however, some cases may take longer than 6 months if there were complications that arose during treatment. If your dog has had this condition before it's advised not to use them again for raccoon hunting due to potential relapse risks. If you have any further questions, please contact your veterinarian.