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Pets Benefit with Access to State-of-the-Art Research Studies
Background Bolt, an eight-year-old German Shepherd was diagnosed in Fall 2012 with perianal fistulas (a painful opening in the skin surrounding the anus). ...
December 1, 2014


Bolt, an eight-year-old German Shepherd was diagnosed in Fall 2012 with perianal fistulas (a painful opening in the skin surrounding the anus). Anal fistulas are very common in this breed of dogs and can be extremely painful.

Leading up to Bolt’s development of these fistulas, owner Paul Higgins describes Bolt’s long history of recurrent skin infections and was referred by his primary care veterinarian at Eastham Vets to a dermatology specialist at VCA in Weymouth. Dr. Loren Cohen was successful in managing Bolt’s skin conditions with cyclosporine; however, a couple years later he developed anal fistulas, which were not resolving. Dr. Cohen had heard about a clinical trial that was being conducted at Cummings School of Veterinary Medicine at Tufts University to treat anal fistulas and suggested that owner Paul Higgins meet faculty member and principal investigator, Lluis Ferrer DVM, PhD, DECVD. Cummings School is a committed part of the One Health initiative that links the human, animal, environmental and research worlds together. “One of our missions is to offer trials that are on the cutting edge of medical advancement, for both animals and humans,” says Dr. Ferrer.

Clinical Trial

The study that Bolt participated in employed the injection of human mesenchymal stem cells into and around the fistulas. The goals of this treatment are to diminish or heal the existing fistulas and either reduce or eliminate the use of certain immunomodulatory agents(a class of drugs) to control the fistulas. Side effects from these drugs, specifically GI upset, made this a less than ideal form of treatment for pets with anal fistulas.

In April 2014 Paul Higgins participated in a brief interview with Cummings School to determine if Bolt would be eligible for the study. Shortly thereafter, Bolt met Dr. Ferrer in North Grafton for an assessment, where it was confirmed that he met all the criteria to participate. Paul joked that he was so proud to have his baby get accepted to Cummings. “It was not without apprehension. We went online and while the information was very technical, I got the general gist of it. When you hear they are going to inject human stem cells into your pet, and anytime you have to subject your pet to sedation, there are worries,” said Paul.


Less than two weeks later, Paul and his wife Christina brought Bolt for the procedure “We were a bit tentative, but from the minute we got there they put our fears at ease. Tufts’ reputation is top notch. They explained everything and we knew immediately we were doing the right thing,” continued Paul.

Dr. Lluis Ferrer administered the stem cells which were supplied as part of a partnership with Advanced Cell Technology of Marlborough, Massachusetts.

Paul speaks graciously about his ongoing communication with Diane Welsh Cummings School’s clinical trial coordinator, who called as soon as Bolt woke up to let them know all had gone well, and also recalled how accommodating they were in scheduling Bolt’s post-procedure appointments.


The clinical trial treatment proved to be successful in healing Bolt’s fistulas. Bolt was monitored for six months, at one week, and monthly post injection. At six months post injection, the fistulas had dissipated and not returned. While the Higgins’ are pleased to have participated in this cutting edge treatment approach, Bolt is not alone with the positive outcome and relief he experienced. The clinical trial was comprised of six patients – 4 German Shepherds, 1 Australian Shepherd and 1 Australian Terrier. All have had their fistulas resolve and the medication decreased. While Bolt is continuing to receive the cyclosporine, it is being used to treat his skin allergies. Dr. Ferrer and his team are very pleased with these positive results and the potential for translation to human medicine. “This study has shown not only to be beneficial to our canine patients, but this research also has implications in helping human patients with Crohn’s disease with similar manifestations and it also has added valuable knowledge about the therapeutic use of stem cells, explains Dr. Ferrer.