Fisher Overcomes Paralysis

Learn About Patient #20-1044

  • Classification: Mammal
  • Species: Pacific Fisher (Pekania pennanti)
  • Length: 30–47 inches from nose to tail
  • Weight: 4-13 pounds
  • Range in the Wild: Northern United States & Canada
  • Habitat in the Wild: Continuous forests
  • Diet: Omnivore
    • Diet in the Wild: Opportunistic feeders, small mammals like snowshoe hare and porcupines, eggs, fruit, mushrooms
    • Birth: Unknown
    • Arrival: 8/29/2020
    • Injury: Paralysis caused by swelling in lower spine
    • Departure: 2/17/2021
    • Gender: Male

The photos were difficult to look at. They were heartbreaking. As rehabilitators we are taught to keep distance between the patient and ourselves. We do that not just for the benefit of the patient but us as well.  Usually, we are pretty good at creating space both physically and emotionally. Patient 20-1044 was different. Patient 20-1044 was a challenge.

Near the end of August a call came in about a Pacific fisher who had been spotted along the road whimpering. The woman noticed that he was quite small, thin, and something just didn’t seem right about the way he stood or moved. The rescuer spent two nights trying to lure him into a live trap. They set up a trail cam to watch. The images revealed a dark, drama filled night, as foxes visited the trap to try and get at the food inside. The timestamps reveal the fisher investigating the trap just two minutes before the foxes. The pictures also revealed the problem. The fisher was dragging its back legs and couldn’t put any weight on them.
Fishers are uncommon patients. The last time the clinic received a fisher was 4 years earlier. Only one member of the current clinic staff had ever treated one. The omnivores are related to weasels, mink, and others. Fishers were once considered endangered in some parts of their home territories due to fur trapping, but their populations are doing better now and they have been reintroduced in areas where they had gone extinct.

The Long Road

An Unusual Patient

When he arrived it was obvious that there was some kind of paralysis to the back side of his body. He had a delayed pain response but couldn’t put any weight on his hind legs.   The fisher was also slightly dehydrated and underweight. He couldn’t lift himself up to go to the bathroom, so he would become covered in his own waste. Things were not looking good. After his intake exam we gave him pain medication, anti-inflammatories, and fluids. We also took X-rays then waited for a diagnosis.
His X-rays were largely inconclusive.
The first day was a challenge. It was hard for staff to watch him struggle and know that if he survived he could be permanently disabled, making him ineligible for release or placement. Euthanasia was considered to ease his suffering, but we decided to give him a few days to see if he improved.
Four days after he arrived, staff was giving him a bath since he couldn’t keep himself clean. They noticed his left back leg was moving voluntarily. Wildlife Images’ staff veterinarian, Dr. Erin Lane, eventually determined that some kind of injury caused severe swelling in his lower spine which was causing paralysis. If we could treat the swelling, we could potentially reverse the paralysis.
The next week was hard. The patient showed little improvement. Despite regular baths from staff he developed skin irritation from urine burns. He started showing signs of infections. Only a single leg was showing any voluntary movement. We reworked his plan, put him on an antibiotic, added medicated ointment and a cone of shame. Another seven days passed and we saw enough improvements to try something new…

Physical Therapy for a Fisher

We started small. We would position his feet properly and then allow him to put his weight on them while supporting his upper body. This is similar to how you might hold a child as they learn to stand. Then we supported him as he walked forward and backward. Some days were better then others. As you can imagine, he was not always the most congenial patient. By a month in we knew the physical therapy was working. We could see some muscle mass returning to his hind quarters, and when sitting or laying he would place his feet properly under him. We moved him into a larger enclosure which allowed him to unknowingly practice his “at-home” physical therapy regimen. Next came hydrotherapy. Under the watchful eyes of our clinic staff, he was placed in a bath tub for a short time. He was able to swim around and strengthen his legs. His instinct was to try to get out, which worked to his advantage since it required him to put weight on his back feet and stretch up to see over the two foot tub. The next therapy introduced was harness therapy.   Staff would hide pieces of his diet in a room. Since he was very food motivated this gave him a reason to move around the room and practice walking while staff supported him with a rear harness. This is a common method used on domestic animals during physical therapy. Eventually, obstacles were placed in his way so he would have to climb up and down to get to the next morsel.
By Thanksgiving we all had something to be grateful for. The fisher patient had improved enough to move to a larger outdoor enclosure. This is a sign that a patient needs less clinical care and that they are working on the skills needed for survival in the wild. We stopped the physical therapy programs and instead created an environment that promoted independent physical therapy. His enclosure had trees, ropes, boards, branches, boxes, shelves and more that would encourage exploration and movement. Little by little we saw his legs drag less and his gate return to normal. He went from limping to dashing across his enclosure. Before 2020 ended he was climbing through a Christmas tree.  As we became more optimistic for release, we needed to reduce his human contact even further to prevent him from becoming habituated to people.

Two Crucial Tests

On New Years Eve we hatched a plan to test his strength, balance and agility.  We placed a long, narrow board across the enclosure, about 5 feet off the ground. If the fisher successfully walked across it we would know he had the skills to survive in the wild. If he failed, then we would allow him more time to strengthen his muscles and improve his coordination. We added an incentive to cross the board (aka food), set up a Critter Cam and waited. The video revealed a fisher that could not only scamper across the board, but leap to and from it and even hang upside down off of it. After a collective sigh of relief it was on to the next test.
The Oregon Department of Fish and Wildlife came by to collect two swabs (one from both ends) from the fisher. We can’t say this patient was a willing participant but we got the swabs and the fisher got a distraction (more food). The tests headed to the lab and would tell us if this patient has (or had) COVID-19. Mustelids are susceptible to the virus and we wanted to be sure we are not introducing it to the wild population of fishers. Two days later the good news arrived from ODFW: the tests were negative. His release was scheduled for less than a week later.

Release & Relief

Far out on Forest Service land we found the perfect spot. Snow glistened in the sunlight as it filtered through the trees. We scattered some food and then opened the door of the crate. It was hard to imagine just six months earlier the patient couldn’t walk and was considered for humane euthanasia. The staff felt a sense of closure as they watched a strong, quick and agile animal return to the wild.