Your Dog Magazine, March 2003

Tufts University College of Veterinary Medicine

New hydrotherapy provides painless exercise

By C.C. Holland
March 2003

Sabina, a 4-year old Rottweiler, clearly wasn't happy.  She limped across the floor of a treatment room at SOL Companion, a canine rehabilitation center in Oakland, Calif., refusing to put weight on one of her hind legs.

"We think it's something neurological," said Nina Patterson, a physical therapist (PT) and the center's co-owner.  It's difficult to rehabilitate a gimpy leg, however, when your patient can't or won't use the limb.  That's where an innovative therapeutic tool, the underwater treadmill, can help.

Veterinary technician Amy Mayfield led Sabina into a large box enclosed with thick, clear plastic.  A standard looking treadmill sat on the bottom.  Sabina stood on the treadmill, her weight on three paws, eyeing liver treats Mayfield held at the ready.  Mayfield reached for the controls, and heated water slowly began to seep into the treadmill chamber.  Sabina waited patiently.  When the water reached about chest height, the water flow ceased, and the treadmill began to move.

Sabina moved with it, her injured paw touching down tentatively at first, then more confidently as she strode along.  When she exited the unit after a 15-minute session, her limp had diminished noticeably.

Sabina's story helps explain why enthusiasm is growing about the underwater treadmill, which was first used on canines about four years ago.  Julie Stuart, MS, PT, at Tufts University School of Veterinary Medicine, said her dream setup for rehab includes an underwater treadmill.

Good for Arthritis

"It's great for orthopedic dogs, dogs with arthritis or with hip dysplasia," she said.  "In water, they can exercise pain-free because it takes away the weight bearing.  The buoyancy makes them bear less weight on their joints, yet it's resistive."

That combination of buoyancy and resistance makes using the underwater treadmill attractive in therapeutic work.  John Sherman, DVM, an affiliate of North Carolina State College of Veterinary Medicine in private practice, has used a unit for nearly two years.

"It's a powerful tool," he said.  "Let's say a dog weighs 100 pounds on land.  You could have him walk [in water] so he'd only weigh 40.  You can get dogs walking and returning to function quicker with an injury or surgical repair."

The concept of the underwater treadmill is obvious:  Partially submerge a dog in water and let him walk on the treadmill.  Heat the water for comfort -- the temperature in the unit Sabina used is kept between 86 and 90 degrees Fahrenheit -- and treat it with a chemical like chlorine or bromine to reduce bacteria levels.  

Technicians adjust the intensity of exercise by adjusting the treadmill's speed and angle, or by adding a current to the water.  They harness or leash dogs -- or both -- for safety and closely monitor them throughout the session.  The treadmill is modeled after a pool or spa, with full filtration and the motor safely enclosed away from water.

The higher the water level on the dog, the less weight he bears.  When a dog walks on land, his forelegs bear 64 percent of his weight and his rear legs, 36 percent, said Patterson, the physical therapist.  In water at hip level, those percentages change dramatically.

"It actually alters the way the dog bears weight," she said.  "In the water, the rear legs almost float and bear only 28 percent of the dog's weight, while the forelegs now take up 72 percent of the load."

Said Donna Chisholm, PT, who also works at SOL Companion: "You get all the benefits of buoyancy along with a reduction of compression forces.  Using the underwater treadmill addresses all areas:  balance, stability, conditioning, strength."

Limited Sales

If so many rehabilitation specialists are gung-ho about the units, why aren't they everywhere?  According to Allan Dahl, director of aquatic therapy for the manufacturer Ferno, only 53 of the company's K9 Underwater Treadmill Systems have been sold since production began four years ago.

One factor may be price.  Ferno's underwater treadmills range from $14,500 to $50,000.  At Tufts, Stuart cited cost as the reason she chose instead to purchase a spa-pool.

Dahl believes the bigger issue is simply the fact canine rehabilitation itself is new.  Only an estimated 30 to 40 facilities in North America are devoted specifically to dogs.  

"Rehab is becoming an important tool in veterinary medicine," he said.  "But getting the vets to accept that therapy is important is taking some time."

Dr. Sherman agreed rehabilitation is a new science for his profession.  When he graduated from veterinary school in 1993, students learned to perform a surgery and then crate the dog for six weeks, with time outside only for elimination.  The dog would then walk on leash for another six weeks.

"That was it," he said.  "That was rehab.  Or you swam them, but really, swimming for a hind-limb injury is just not that effective a therapy."

That mindset began to change when human physical therapy became popular.  Some veterinarians and physical therapists began considering translating human therapeutic modalities to the canine world.  One was Laurie McCauley, DVM, an Illinois veterinarian in private practice.  Four years ago she approached Ferno, which at the time was making underwater treadmills for human and equine use.

"They thought I was crazy, but they worked with me," she said.  "It's such a great exercise, but it's safe for a 90-year-old lady with a hip replacement.  So I thought it would be great for arthritic dogs."

Dr. McCauley gave Dahl a wish list.  In return, Ferno developed its first canine underwater treadmill, a unit that attached to her existing pool and used a Jet-Ski lift to vary the water height.  Today, Dr. McCauley has two underwater treadmills at her TOPS Veterinary Rehabilitation center in Grayslake, Ill. and said about a dozen dogs a day benefit from them.

Run Up Stairs

"I've had dogs with neurological injury that have used their legs a full two weeks in the water before they used them on land," said Dr. McCauley.  "A lot of the arthritic dogs do great with it.  Their owners tell me they go home and are running up and down stairs, doing things they haven't done for six months."

David Levine, Ph.D., PT, Orthopedic Certified Specialist, American Board of Physical Therapy Specialties, adjunct associate professor at the University of Tennessee at Chattanooga's College of Veterinary Medicine, echoed her enthusiasm.  The university was an early adopter of the underwater treadmill and worked with Ferno to design and modify the first units.

"I think early on, especially early post-operatively, it's a really wonderful rehab tool to get (a dog) to start using a limb a lot easier than we normally could have outside with just walking," he said.  "It's enhanced our ability to rehabilitate post-op dogs more quickly and to a higher level."

Dogs generally seem to like the underwater treadmill. "The love the warm water (kept at 90 to 94 degrees, depending on the weather) and the massage at the end," Dr. McCauley said.

"They're in their element," said Chisholm.  "They walk.  They swim." 

A few don't enjoy the water, however, and some don't know what's expected of them.  Dr. Sherman recalled a dog who couldn't understand the concept of water and walking.  "He either wanted to lay down or try to swim."

Of course, the people operating the treadmills need to be knowledgeable about their work.  "The underwater treadmill, like anything, is just a tool to be used," said Dr. Sherman.  "If you just put a dog in there and expect him to get better, you can get into trouble.  Every patient that comes in, you have to give a full physical exam, see where they are in the healing process and monitor their progress.  In the wrong hands, if you just turned it on and didn't know what you were doing, that would be a problem."

Set up a Schedule

The underwater treadmill should be used as part of an overall treatment plan rather than it's sole focus.  For example, a typical surgical rehabilitation schedule at SOL Companion would begin one to two weeks post-operatively and include passive range-of-motion exercises three times a day, daily walking from up to 10 minutes at at time and crating to limit movement.  A month to six weeks later, the dog would begin two to three sessions where he'd undergo hands-on tissue work, hydrotherapy and movement therapy, while continuing at-home work with the owner.

The cost of animal rehabilitation varies with the provider but generally ranges from $50 to $125 per session.  Most therapists' fees are based on time rather than on equipment although some bill differently for a hydrotherapy-only session.  For example, Dr. Sherman charges a flat rate of $120 for an hour, regardless of modalities used.  Dr. McCauley bills $49 per session, up to 20 minutes, for hydrotherapy, with other treatments at an additional charge.  SOL Companion's rates are $75 for an hour of hands-on work, $50 for a half-hour with the underwater treadmill and $125 for a combination of both.

Those best qualified to work with dogs on the underwater treadmill include physical therapists who've expanded their practices to include dogs and veterinarians or veterinary technicians who have formal training in animal rehabilitation.

Currently, there's no such title as an "animal physical therapist," although some specialized training programs exist.  The term "physical therapist" is reserved for professionals who work with humans.

While some dogs respond very well, hydrotherapy shouldn't be viewed as the magic bullet, Patterson warned.  Her center, which has one underwater treadmill but is chock-full of therapeutic equipment, including balance boards, oversized balls and even a mini-trampoline, bears her out.

Still, it's a promising therapy that could become a new standard of care.  And while results so far are strictly anecdotal -- no rigorous studies of outcomes have been done -- word of mouth has been encouraging.  Dr. Sherman believes the treadmills someday will be available in every major metropolitan area.  "In my opinion, this will be an up and coming veterinary specialty."

As for Sabina, she's still in rehab.  Patterson said her case is trickier than most.  "She'd be improving much more quickly if this were a surgical rehab rather than a nerve entrapment, which is what we suspect is going on," she said, but she still showed marked improvement.  Her time on the underwater treadmill has increased from 8 to 20 minutes and the prognosis is good.

"When we first saw her in November 2002, she was completely non weight-bearing with her left hind limb on hard surfaces," Patterson said.  "Now, although it's still intermittent, she's able to bear weight."

Thanks to the underwater treadmill, Sabina's on her way to becoming another rehabilitation success story.