Post-surgical, degenerative joint disease and obesity cases among primary candidates for physical therapy.

By Susan Bertram, DVM
January, 2000

The trend of offering expanded services is motivating many veterinarians to consider how physical therapy and rehabilitation can benefit their patients and their practices.  Veterinarians see cases daily that could benefit from physical therapy, such as post-surgical orthopedic and neurologic cases, tendonitis, obesity, nerve injury, degenerative joint disease, and chronic wounds.  Consumer demand is also a driving force.  Owners of performance animals, such as race horses, show horses and racing greyhounds, can reap an economic benefit if physical therapy can return valuable animals to competition.

"The human-animal bond is a tremendous motivation for owners to seek referral of their pets for physical therapy," said Jane Avery, PT, CVT who operates a pet rehabilitation service based in Denver.  Although Avery accepts cases by veterinary referral only, it's usually the pet owners who initiate the process.  "Owners want to know they are doing everything they can to help their animals," Avery said.

With the goal of providing a level of care to his veterinary patients comparable to that found in human medicine, Paul Shealy, DVM, Dipl. American College of Veterinary Surgeons (ACVS) invested in high quality equipment and facilities needed to provide physical therapy and rehabilitation at his referral practice, Veterinary Specialists of the South East in Charleston, S.C.  Dr. Shealy consults regularly with a licensed physical therapist (PT) and employs a physical therapy assistant (PTA).  All patients recovering from orthopedic or neurologic surgeries are provided rehabilitation services, included in the cost of the surgery.  In the initial nine months of the program, Dr. Shealy said, "The speed of recovery, and the quality of recovery, has really gotten our attention."  Encouraged by success with surgical cases, physical therapy and rehabilitation (PT/rehab) is now offered to patients receiving non-surgical treatment for spinal discs, spinal cord and nerve injury, osteoarthritis, and other chronic, degenerative diseases.  "We are seeing results with cases where previously we threw up our hands and told owners, 'There isn't anything else we can do,'  Shealy said.  "We haven't yet found all the potential indications, or put this type of therapy into full use."

Changing Views

Post-surgical rehabilitation of veterinary patients isn't a revolutionary idea, but is generally under-utilized or initiated only after the surgery is deemed a failure.  The common practice of crating a dog or otherwise strictly limiting a surgery patient's activity is associated with severe muscle atrophy, decreased range of motion, and persistent dysfunction.  These in turn contribute to re-injury and certainly to decreased satisfaction, in the pet owner's mind, with an expensive surgical procedure.

Most veterinarians wait too long to begin physiotherapy on post-operative patients, said Robert Taylor, DVM, Dipl. ACVS, in his lectures at the First International Symposium on Physical Therapy and Rehabilitation in Veterinary Medicine, held in Corvallis, Ore., last August.  Dr. Taylor and others believe physical therapy should begin the day of surgery.  In the first 24 to 72 hours post operatively, cryotherapy will minimize swelling and decrease pain.  Commercial ice packs that remain malleable when frozen and conform to the limb are convenient and re-usable.  Passive range of motion (ROM) exercises promote lymphatic and venous drainage, and are believed to aid in re-orientation of fibroblasts in a more normal pattern during healing.

As much as possible, owners should be involved in their animal's care, Taylor said.  Avery agreed.  "In some cases, owners can be the very best therapist for their pet," Avery said.  Ideally, Avery meets her patients' owners at the veterinarians office on the day of discharge and instructs owners how to begin physiotherapy at home with passive range of motion exercises.  Sit-to-stand, standing and weight-shifting exercises may be added.

During follow-up treatments either at the veterinary hospital or at the owner's home, other modalities are implemented when appropriate to the stage of healing.  Electrical stimulation of motor nerves and/or hydrotherapy can combat muscle atrophy, preserve strength, and help regain proprioception and balance, with the goal of earlier return to function.

Veterinarians wishing to institute a physical therapy program have some homework to do.  Acquiring knowledge of equipment, clinical indications for each modality, proper application and contraindications is essential.  Continuing education courses are available in this emerging field.  Consulting with, employing or referring cases to a licensed physical therapist is a good way to tap into their unique knowledge and experience, but check the state's practice act for both professions for limitations and guidelines.  To date, there is no certification program in animal physical therapy, so human physical therapists working with veterinarians must learn the anatomic, physiologic, and biomechanical differences of quadrupeds.

Little published information is available on physical therapy for animals so protocols tend to be adapted from human medicine.  David Levine, Ph.D., PT, associate professor in the Department of Physical Therapy at the University of Tennessee, is collaborating on research with veterinarians at the school's College of Veterinary Medicine.  "A number of researchers here and at other universities are now studying the outcomes of physical therapy intervention on veterinary species," Dr. Levine said.  "We are focusing on the modalities already validated in human medicine, such as therapeutic ultrasound, neuromuscular stimulation and hydrotherapy," he added.

Hydrotherapy, or use of whirlpools and swimming, is a mainstay of human PT/rehab.  Water provides buoyancy, which decreases stress on joints, and resistance, which promote muscle strengthening with swimming.  Immersion in warm water affords thermal benefits:  increasing circulation and joint mobility, and decreasing pain.  Many veterinarians have at some point recommended swimming as a safe exercise for an arthritic or obese canine patients.

Underwater treadmills take the concept of hydrotherapy one step further, and have been used in equine patients since the 1970s.  Water temperature, level of patient submersion, water resistance (whirlpool jets) and speed of treadmill can be controlled for maximal benefits.  Laurie McCauley, DVM, owner of TOPS Veterinary Rehabilitation in Grayslake, IL. helped design the first underwater treadmill for dogs, and it has become an integral part of her rehab program.

In combination with other therapeutic modalities, Dr. McCauley has used the hydro-treadmill to successfully rehabilitate a number of patients given a poor prognosis for recovery, with diagnoses such as brachial plexus injury, fibrocartilagenous emboli, degenerative myelopathy and quadriplegia from cervical disc herniation.  "It's very exciting when cases that everyone else has given up on not only get better, but end up being able to walk and in some cases, run" she said.  McCauley left general practice to focus exclusively on veterinary rehabilitation.  After one year, her caseload has increased to the point where she now employs two other veterinarians part-time.

Therapeutic ultrasound (US) is another modality with great potential in veterinary patients.  US produces localized heating in deep tissues, especially muscles and tendons, and promotes increases in blood flow, increased collagen extensibility, reduced pain, changes in nerve conduction velocity, and enzyme activity.  In humans, it is used to treat tendonitis, improve ROM, treat sprains, edema, reduce scar tissue, joint contracture, exostosis and myositis.

Shealy cited a memorable case involving a dog debilitated by chronic masticatory myositis.  Upon presentation, the dog couldn't open its mouth enough to fit a pencil in, due to severe muscle contracture.  Using a combination of US to aid in breaking down the contracture and scar tissue, followed by passive ROM exercises (a PT principle known as "heat and stretch") the dogs was successfully rehabilitated.  "After 12 treatments, the dog is able to open its mouth, and is retrieving the newspaper again," Shealy said.  "One example doesn't prove it will work in all cases, but I don't think I've ever seen such a dramatic recovery."

Neuromuscular electrical stimulation (NMES) is a therapeutic modality indicated for treatment of muscle atrophy, pain, edema, muscle spasm, increasing ROM, muscle strengthening and re-education, for example, in recovery from cruciate or other orthopedic surgeries.  Electrical muscle stimulation (EMS) directly stimulates denervated muscle in patients with spinal cord injuries.

One of McCauley's patients illustrates the benefit of using NMES.  A 4-year old golden retriever was quadriplegic following a vascular accident in the spinal canal at L5-L7.  After 10 days with no response to dexamethasone, the case was referred to McCauley.  NMES therapy was initiated on an outpatient basis, every other day to once weekly for the first month, at which point the dog could stand assisted but not walk on its rear limbs. Hydro-treadmill therapy was added and after three sessions the dog could walk unassisted for short distances.  Ultimately the patient recovered fully, able to walk and even run.  "The NMES and hydro-treadmill therapy were not responsible for the nerve regeneration seen in this case, but they prevented atrophy, and improved strength and coordination as regeneration occurred," McCauley said.

Newer Frontiers

Some therapeutic modalities, such as magnet therapy and monochromatic infrared energy, have limited FDA approval for use in humans in the United States.  Anecdotal evidence of additional benefits, outside the scope of their FDA-approval, has sparked interest in further study.

Low-intensity laser therapy (LILT) devices produce infrared or visible red monochromatic light, and have been used in Europe for more than 30 years for pain relief and wound healing.  Recently in England, LILT has been the subject of controlled scientific studies, and published effects on would healing include increase in growth factor release from macrophages, enhanced synthesis of ATP, increase in angiogenesis, collagen synthesis and myofibroblast activity.  Another possible mechanism of action is local increase in nitrous oxide (NO) concentrations in tissues, which as been documented in human patients treated with 890 nm monochromatic infrared light.  Increased NO is believed to produce vasodilation and anabolic effects, and may explain enhanced wound healing seen with topical nitroglycerin or oral L-arginine therapy.  Alteration in neurochemistry or nerve conduction velocity may be the mechanisms for LILT's reported effect of pain relief.

Recently, photon or photo-therapy devices that use superluminous diodes to produce monochromatic light instead of true laser-emitting diodes have become available and are purported to have similar effects.  Photon-therapy is being used in the United States in the horse-racing industry to treat pain and inflammation and exercise-induced pulmonary hemorrhage.  Treatment of large open wounds, laminitis, navicular disease and arthritis are other potential applications according to some manufacturers.  At the San Diego Zoo, a 57-year-old elephant was treated with a phototherapy device for chronic osteoarthritis of a carpal joint.  The staff veterinarian noted significant symptomatic relief, whereas other medical and drug therapy had failed.

Pulsed electromagnetic field (PEMF) refers to the use of electric current to generate a magnetic field for therapeutic purposes.  Magnetic field therapy is commonly used by veterinarians in Australia to treat racing greyhounds with sesamoiditis, acute and chronic hock joint injuries, pain, reduced range of motion, and acute and chronic muscle, tendon and ligament injuries.  Currently, PEMF is FDA-approved in human medicine for therapy of delayed union/non-union of bone fractures.  Further research is needed to document other reported effects.

According to some manufacturers of PEMF devices, frequencies of about 18 Hz tends to promote vasodilation, while frequencies approaching .5 Hz cause vasoconstriction.  Frequency can therefore be adjusted to either enhance blood flow for treating chronic injuries, or to reduce flow and minimize inflammation or edema following acute injury.  PEMF penetrates bandages and plastic splints, which is convenient for wound therapy.  In a study conducted at Scott-Ritchey Research Center at the University of Auburn (Swaim, et al), early re-epithelialization of wounds was noted with PEMF application.  Static magnetic fields are also available in forms such as pads, boots and blankets to be worn by the patient, but research is needed to verify their reported analgesic effects.

Practice Benefits

The cost of setting up a comprehensive, effective physical therapy /rehabilitation program is high and includes investment in quality equipment, construction or purchase of a pool or other hydrotherapy unit, and hiring additional staff.  Shealy suggested one solution would be for an entire veterinary community to invest in and support a physical therapy/rehabilitation facility, as many currently do for emergency hospitals.  He noted that the return on the investment can't be compared to something like buying an X-ray machine.  "The results obtained have a positive effect in that it gives owners more confidence in our professional abilities," Shealy said.  "It's going to take some time to change our mind-set and realize there is something more we can do; we can get better results in many of these cases.  Our patients are going to be the ultimate benefactors."

McCauley is currently writing a chapter and section for a book on canine rehabilitation, slated for publication in 2001.  She is also active in lecturing on the subject at veterinary and physical therapy continuing education conferences.  "Physical therapy and rehabilitation in veterinary medicine is a field with enormous potential for growth," McCauley said.  "It will expand because of successful results."