by Krista Niebaum, MPT, CCRT, Director of Rehab Therapy at Scout’s House
Coonhound paralysis is an acute polyradiculoneuritis that was first recognized in the Coonhound breed and appeared to be associated with exposure to raccoon saliva (via a scratch or bite). However, it is now known that it can affect any breed and also occur without any apparent raccoon exposure. Current thought is that Coonhound paralysis is an immune-mediated disease with onset of signs occurring 1-2 weeks after exposure to the trigger. Typical signs include a stiff-limbed gait that progresses to weakness or paralysis of all limbs (LMN tetraparesis or tetraplegia). Weakness usually begins in the hind limbs, then progresses forward to involve the forelimbs. Muscle atrophy rapidly occurs. Spinal reflexes are lost but pain perception remains intact. In many affected dogs, the ability to vocalize is compromised. Respiratory paralysis may also develop, necessitating mechanical ventilator support. Signs can continue to progress for up to 10 days, then may last for up to 4 months. Pain sensation remains intact and bowel/ bladder continence is maintained.
Treatment options for Coonhound paralysis are limited, but the prognosis for full recovery is good. Glucocorticosteroids have not been found to be effective. High dose IV immune globulin therapy can be used but is expensive. Time for the damaged axons to remyelinate is required. Ensuring that good nursing care and nutrition is provided at home is key. Physical rehabilitation is also believed to maximize functional recovery.
Halley, a female Brittany Spaniel, was estimated to be 4 ½ years old when she was left in a shelter drop box in northern California. At the time of her intake examination, she was only able to wag her tail. She was also able to breathe without difficulty. Otherwise, Halley was paralyzed. As she arrived at the shelter without any history, several diagnoses were considered to explain Halley’s tetraparesis, including spinal trauma, tick paralysis, botulism, myasthenia gravis, and rabies. After thorough examination at the veterinary emergency clinic, Halley was given the diagnosis of Coonhound paralysis. Halley was a very lucky girl as she was rescued and then fostered by a member of the American Brittany Rescue group one week later. When Halley was discharged to her foster owner’s care, instructions were given for passive range of motion activities and an appropriate repositioning schedule to avoid skin breakdown. She was also referred to Scout’s House for physical rehabilitation.
Halley arrived at Scout’s House for her rehabilitation evaluation four weeks after she was initially left at the shelter. By that time, she had regained the ability to actively move her head and neck against gravity through small ranges of motion, but she remained dependent with all functional mobility. She lacked voluntary movement of her trunk and limbs, but she was still able to wag her tail. Spinal reflexes were absent (except perineal reflex, which was normal). She presented in lateral recumbency and required complete assistance to move to and maintain sternal position. When moved into a supported sitting or standing position, Halley required complete assistance and was unable to accept weight through any of her limbs. Muscle atrophy was observed throughout all four limbs and trunk, and the abdomen appeared distended due to lack of abdominal tone. Pain perception was present, but she still lacked withdrawal. Halley was continent of bowel and bladder; her owner carried her outside several times each day for eliminations (performed in lateral recumbency). Despite her debilitated status, Halley appeared in good spirits and wagged her tail whenever someone interacted with her.
Halley was initially seen at Scout’s House at a treatment frequency of one session every 1-2 weeks. These early sessions included neuromuscular electrical stimulation use, Proprioceptive Neuromuscular Facilitation techniques to begin addressing trunk stability, and stretching/soft splinting of bilateral carpi due to mild flexion contracture development. Focus was also placed on owner education and instruction in an appropriate home exercise program. Halley’s foster owner was instructed in positioning methods for joint protection and postural re-education, passive range of motion and stretching techniques, and her own proper body mechanics to avoid injuring herself when transporting Halley around her home and yard.
At approximately two months after onset, Halley was able to maintain a sternal position without support (once positioned) even while eating her meals. She also began showing voluntary movement of proximal musculature of all four limbs (forelimbs greater than hind limbs) and increased trunk control. Given this improved strength and motor control, facilitated rolling activities were initiated to promote independence when transitioning between lateral recumbency and sternal. Balance activities, such as small-range reaches for treats while positioned in sternal, were included in her program. Two weeks later, Halley’s foster owner reported observing Halley moving herself into sternal. She was also starting to scoot/commando crawl short distances in the home.
At three months post-onset, Halley’s treatment frequency was increased to two sessions per week as her strength and endurance gains allowed for a more intense rehab program. Neuro-Developmental Treatment techniques were utilized to assist and facilitate transition from sternal into supported sit. A physioroll was used to support Halley in a standing position while gentle weight shifting and manual contacts encouraged activation of anti-gravity musculature.
At four months, Halley’s foster owner reported that Halley was able to stand without assistance for two minutes (once assisted into stand). She continued to require facilitation during transitions from sternal into sit (minimal assistance) and sit into stand (moderate assistance). One week later, Halley was able to independently move herself from sternal into sit. Therapy sessions continued to include facilitated sit to stands and progressed to include pre-gait activities such as standing weight shifting in water and use of an overhead lift with sling support “on land.”
When the five month mark was reached, Halley and her owner (who had now formally “adopted” Halley) surprised the rehab staff by walking into the clinic. Halley’s gait was slow and stilted, she demonstrated a wide base of support with her hind limbs, and she lack tarsal flexion bilaterally during swing phase, but she was able to ambulate on level surfaces without assistance. Although a front harness was still used for safety, Halley was also able to perform all transitional movements independently at this time.
Halley continued her therapy intermittently over the following three months to address coordination, gait quality, and mobility over varied surfaces, including stairs. Underwater treadmill walking, Cavaletti rails, wobble boards, and weaves were added to her program. Today, she is able to negotiate stairs, trot over uneven ground, jump up onto the owner’s bed, and has even participated in mock field work with other dogs in the local Brittany club. Although Halley’s prior level of function is unknown, her current mobility suggests that she has experienced a full recovery.
As demonstrated by Halley’s case, Coonhound paralysis can be a debilitating disease with a prolonged recovery time. However, with time and consistent care from a dedicated owner and rehabilitation team, the functional outcome for these patients can be excellent. Watching a previously paralyzed dog running and playing in a field is certainly a wonderful reward for everyone’s hard work.