Breakthrough Surgical Procedure Relieves Dogs from Chronic Pain

A vivacious two-year-old Labrador Retriever, Finn started having trouble walking up the stairs. “We didn’t think much of it, at first, but then things progressed,” explains Finn’s owner Amanda Rinderle (she/her), noting that Finn became increasingly sore, he was not pushing off with his back legs and needed to be carried upstairs.

After seeing an orthopedic surgeon and a neurologist and trying some conservative treatment—including steroids, painkillers, and physical therapy—nothing seemed to help.

Chronic pain in a dog can be difficult to recognize and diagnose. “If your dog is acting abnormally, pain is a common cause, but it can be difficult to diagnose,” says Dr. Elizabeth Parsley (she/her), assistant professor in the Department of Clinical Sciences at Cummings School of Veterinary Medicine.

The first case of tethered cord syndrome
Parsley’s first involvement in this area began when a former coworker had a dog with a vague painful syndrome and was diagnosed with immune-mediated polyarthropathy, which attacks the joints. Unresponsive to treatments and appearing to have pain in several locations, Parsley examined the canine and when lower back pain was suspected, an MRI was conducted. 

Suspicious of tethered cord syndrome (TCS), Parsley shares that by good fortune a friend [with TCS] was serving as a postdoc for a human neurosurgeon, specializing in tethered cord syndrome. “I shared the MRI and the neurosurgeon agreed with my findings and helped me complete the first interoperative surgery for this condition using best practices in human medicine. This involved a surgical technique that has not been previously described in veterinary medicine.”

According to Parsley, because of the poor descriptions and difficulties in diagnosing this condition, some practitioners have either never heard of it or don’t believe it exists. Experience from her first case of canine tethered cord syndrome showed Parsley what to look for.

The search for possible causes for pain requires a full work-up, she says, including ruling out orthopedic problems, inflammatory diseases, and a neurologic evaluation. “An MRI is where we find abnormalities consistent with tethered cord syndrome. We look at the end of the spinal cord for a tethered appearance or if it is pulled upward. We will also move the dog’s back in different positions to see if the spinal cord is moving as we’d expect. With a tethered cord, the abnormal tension does not allow normal movement of the spinal cord.”

Parsley contends, “Right now, we don’t know how many dogs look tethered in an MRI but aren’t truly symptomatic for tethered cord syndrome, which can make the diagnosis very challenging.” 

“Dogs with this condition usually have discomfort on the lower spine and typically experience pain with tail manipulation. If you bend their tail up, it’s painful,” she says.

“They can also have perineal discomfort. A few of my patients with TCS have had discomfort when trying to relieve themselves or have had spasms in that area, which is consistent in humans with this syndrome and can be a cause of pain. They can also chew at their hind legs due to an abnormal sensation they’re having.”

Finn’s treatment by Dr. Parsley
Finn’s orthopedic surgeon had previously worked with Parsley and knew that she had worked with dogs who had been diagnosed with tethered cord syndrome. The surgeon was suspicious of that as the cause of Finn’s pain and referred him to Dr. Parsley for further evaluation.

An MRI and some additional testing confirmed what the surgeon had suspected, it was most likely tethered cord syndrome and surgery was Finn’s best option to relieve his pain. Since 2019, Parsley has overseen nearly a dozen cases, with eight treated via surgery, including Finn. 

“The surgery to address tethered cord syndrome entails cutting the piece of connective tissue at the end of the spinal cord called the filum terminale,” Parsley explains. “You transect the filum to release that tension. In veterinary medicine, the only documented approach is the extradural approach, or the part of that connective tissue outside the sac around the spinal cord. Human medicine recommends doing the intradural approach, or the part that’s inside the sac around the spinal cord, which is what I did.”

Prior to the procedure, “Finn woke up from a full depth of anesthesia when we moved his tail,” Parsley says. “And now, post-surgery, I can fully extend his tail without any issue.” 

Rinderle has witnessed Finn’s remarkable transformation. “He was an unhappy dog pre-surgery—in pain, on medication, and having trouble walking. He was so young that we had to give him a chance at something better,” she shares.

The night after the procedure, Rinderle noticed a profound difference in Finn. “Despite having this invasive surgery, he was already more comfortable. He would not let us touch his back half before, which he lets us do now. He’s running around outside with his friends now and is so much happier.”

All of Parsley’s surgical tethered cord cases are doing markedly better. “It’s been a fascinating, translational One Health-type of approach,” she explains. “We have involved the human neurosurgeon in all of the cases to confirm my diagnosis.” 

A pioneer of canine tethered cord syndrome surgeries
According to Parsley, as of early February, there were only three case reports in published literature about dogs with tethered cord syndrome.

Parsley virtually presented a poster about the topic for the European College of Veterinary Neurology Symposium and co-presented a talk with Dr. Abigail McElroy, V17, at the Bobby Jones Think Tank Meeting, both in 2021.

“Abby has participated in surgeries in humans and autopsies with horses during her postdoctoral assignment and has become skilled in identifying tethered cord syndrome and the filum, so she has been a wonderful resource,” says Parsley. McElroy is a Ph.D. candidate at UMass Medical Center.

Currently undocumented, Parsley is eager to be the first to author an article about her work on tethered cord syndrome and the intradural approach. “It’s forthcoming,” she says.

Rinderle was thrilled by her experience with Finn’s treatment and hopes that other dog owners with similar issues will consider this option. “I think that Dr. Parsley is a genius because she healed our dog after nearly two years of trying alternative treatments,” Rinderle beams. 

“She is also the most compassionate person. We’ve kept in touch after the surgery and when Finn had a back spasm on a Saturday morning, I emailed her and she met me at Cummings School an hour later to help treat Finn. She is the most caring vet you could ask for.”