Introduction

Canine rehabilitation is a relatively new discipline with interest starting initially in the 1980s throughout the 1990s and resulting in the formation of the Animal Physical Therapy Association (APTA). The current practice now draws from the knowledge and skills of veterinarians, veterinary technicians, human physiotherapists and physiotherapy assistants. Many of us have experienced firsthand the benefits of physiotherapy following injury and/or surgery and thus it would seem logical that our veterinary patients would experience the same benefits. That being said, there is a paucity of quality publications in the literature that provide strong evidence that rehabilitation is beneficial. With increasing client interest in veterinary rehabilitation, the availability of training courses for veterinarians and veterinary technicians and the recent formation of the American College of Veterinary Sports Medicine (ACVSMR), hopefully we see strong evidence supporting this practice. This evidence will move the discipline forward to better treat our veterinary patients and make rehabilitation an important option just like prescribing a medication or performing surgery.

Why is Rehabilitation Important?

Our veterinary patients are no different than the human population with regards to the need for rehabilitation. They experience injury and degenerative processes that result in changes in structure and function in the body. Our patients undergo surgery for fractures, ligament ruptures, neurological conditions and soft tissue excisions. They also are affected by non-surgical soft tissue injuries and conditions such as obesity and osteoarthritis. Many of these conditions are devastating and complete recovery may not be possible, but rehabilitation can help to improve day to day function and improve quality of life.

Benefits of Rehabilitation

The following are perceived benefits of rehabilitation:

• Increased speed of recovery following injury or surgery.
• Improvement in quality of movement and performance.
• Increased strength and endurance.
• Improvement in flexibility and biomechanics.
• Reduction in the incidence of future injury both due to restoration of normal biomechanics and through client/owner education.
• Reduced pain.
• Positive psychological effect for both the pet and for the owner.
• Minimally invasive approach.
• Minimal complications if administered properly.

Rehabilitation Techniques and Modalities Cryotherapy

When tissues are inflamed, pain management and rehabilitation start with cryotherapy. Cryotherapy is an inexpensive and readily available modality that is effective for reducing swelling and inflammation for tissues that are chronically inflamed, recently injured, or postoperative. It can consist of ice packs, ice wraps, and cold compression wraps and can be as simple as a bag of frozen peas a Ziplock™ bag with two parts water and one part alcohol or as complicated as a Game Ready™ cold compressive therapy unit. Using compression such as an elastic wrap can further decrease the temperature of the deeper tissues. Cryotherapy is most effective when inflammation is present.

Investigation of dogs undergoing extracapsular repair for cranial cruciate ligament rupture found that cold compression and cold compression with bandaging were found to be equally beneficial in reducing stifle swelling in the first 72 hours.¹ Cold compression was applied for 20 minutes by wrapping the leg from the stifle to the hock with a large cold pack and holding it in place with an elastic bandage once daily. Another recent study reported that CCT decreased signs of pain, swelling, and lameness and increased stifle joint range of motion in dogs during the first 24 hours after TPLO.²

Therapeutic Ultrasound (TUS)

Therapeutic ultrasound has been used widely in human rehabilitation as being an effective treatment modality for rehabilitating musculoskeletal conditions such as restricted range of motion (ROM) resulting from joint contracture, pain and muscle spasm, and wound healing. Many protocols for the administration of US are based on tradition or extrapolated from basic science research and remain to be tested in controlled clinical trials.

Proposed Mechanism of Action

Energy within a sound beam decreases as it travels through tissue, because of scatter and absorption. Scattering is the deflection of sound out of the beam when it strikes a reflecting surface. The transfer of energy from the sound beam to the tissues is through absorption. Absorption is higher in tissues with high protein content and relatively low in fatty tissue. The creation of a thermal effect is a major indication for the use therapeutic US.

Increasing tissue temperature may increase collagen extensibility, blood flow, pain threshold, and enzyme activity, as well as mild inflammatory reactions, and changes in nerve conduction velocity. Treatment with US for 10–20 minutes at high intensities, skeletal muscle temperature and blood flow increase. Thermal effects of TUS can be effective in addressing scar tissue, joint restriction associated with periarticular structures, muscle spasm, and non-acute soft tissue injuries. Nonthermal effects of TUS can facilitate healing of acute soft tissue injuries and peripheral nerve injuries.

Low Level Laser Therapy (LLLT)

Over the past 6 or 7 years this modality has been gaining popularity for treatment of a variety of conditions in veterinary medicine. In 2015, it was estimated that close to 20% of veterinary hospitals in North America were using a therapeutic laser in their practice. This is likely due to an increased awareness and deployment of veterinary rehabilitation services, availability of educational resources on therapy lasers, and the development of products and protocols that have resulted in more consistent clinical outcomes. Laser therapy is considered a noninvasive, drug-free treatment option, providing clients with a nonpharmacologic treatment option. Quality research in the area of photobiomodulation in veterinary medicine is scarce. Much of the information advocating use of lasers is extrapolated from in vitro studies or from studies performed in other species. Published, well-designed studies are for the most part not available in veterinary species.

Proposed Mechanism of Action

It is proposed that LLLT modulates cellular functions by a process known as photobiostimulation. Therapy lasers induce a nonthermal interaction of monochromatic radiation with the tissues requiring treatment. The physiologic effect of this type of energy application on tissue is still not completely understood. LLLT has been reported to modulate various biologic processes, such as mitochondrial respiration and adenosine triphosphate (ATP) synthesis, to accelerate wound and joint healing, and to promote muscle regeneration. Acute and chronic pain control has been reported using this type of low-energy photon therapy. Treatment of chronic and acute edema, neurologic conditions, and postoperative care are some other popular conditions treated with laser therapy.

Indications for Use of LLLT

The efficacy of LLLT remains controversial in veterinary medicine. Some veterinary studies have shown some promise for use of LLLT for preservation of cartilage properties, improvement in peripheral nerve injuries, and as a possible adjunct to managing pain in patients with osteoarthritis. Laser therapy may have some benefit in early wound healing.

Extracorporeal Shock Wave Therapy (ESWT)

Extracorporeal shock wave therapy (ESWT) was initially introduced in human medicine in the early 1980s as a noninvasive method for reducing the size of nephroliths. Increasingly ESWT is being suggested as treatment for certain musculoskeletal conditions in humans and veterinary patients. Reported benefits include pain relief, antibacterial properties and improved wound, bone, tendon, and ligament healing.

Proposed Mechanism of Action

The exact mechanism of action of ESWT is not well understood. One theory proposes that mechanical stimulation from soundwaves results in the expression of growth factors and cytokines involved in the healing process. ESWT applied to chronically injured tissues may restart the inflammatory process and facilitate healing by causing the release of inflammatory mediators. The proposed mechanism believed to be responsible for pain relief is related to increased serotonin activity in the dorsal horn, and descending inhibition of pain signals.

Indications for Use of ESWT

ESWT has been reported to be beneficial as an ancillary treatment in cases of osteoarthritis. One study reported improved weight bearing and passive range of motion are similar to results expected with NSAID treatment. On occasions when NSAIDs cannot be prescribed, extracorporeal shockwaves therapy may provide an alternative for treatment of osteoarthritic conditions. Anecdotal reports indicate that conditions affecting the elbow, hip, or back treatment of conditions may be more responsive to ESWT than other joints. Other reported indications for ESWT include delayed or nonunion fractures, wound management, tendinopathies and ligament injuries.

Evidence for the Effectiveness of ESWT

In treating dogs with hip and elbow OA is equivocal. Dogs treated with ESWT for these conditions showed improvement with objective measures but were not statistically significantly better when compared to controls.^3-5 Another group reported that dogs with elbow OA improved with ESWT is similar fashion to what would be expected when treated with a nonsteroidal anti-inflammatory drug (NSAID), although these dogs were already receiving treatment for their arthritis, including NSAIDs.⁶

Electrical Stimulation (EStim)

Electrical stimulation (EStim) is commonly used in human physiotherapy to increase muscle strength, improve joint range of motion, re-educate muscles, and decrease edema and pain. There are both pain management and muscle stimulation modes for this modality. Transcutaneous electrical nerve stimulation (TENS) is commonly used to treat a specific area of pain or to stimulate a particular muscle in order to combat muscle atrophy. These TENS units are readily available, battery powered and inexpensive. Neuromuscular electrical stimulation (NMES) resulted in hypertrophy of the vastus lateralis muscle in dogs after induced muscle atrophy using immobilization in one study. Although there was no difference between dogs receiving NMES and untreated controls regarding thigh circumference, cross-sectional morphometry of vastus lateralis fibers of treated dogs was greater on day 90 compared with that observed at the time of immobilization and untreated controls. Treated dogs also had improved goniometric measurements 30 days after immobilization ended.⁷ TENS has also been investigated for treatment of osteoarthritic stifle pain and was shown to improve ground reaction forces in treated dogs but only for a short duration of 210 minutes.⁸

Hydrotherapy

Hydrotherapy in the form of the underwater treadmill is one of the most effective methods of providing controlled and targeted therapy for our patients. It’s benefits in pain relief in postoperative, neurological, and chronic OA patients are a result of the effects of buoyancy, hydrostatic pressure and temperature. It provides safe, controlled, supportive and non-explosive activity that is ideal for weight loss, hip dysplasia, FHO patients. The one unfortunate drawback of under-water treadmills is the expense, space requirement, and maintenance of the equipment.

Therapeutic Exercises

The true gains made in any rehabilitation protocol are made through exercise. Most of the modalities mentioned previously are intended to provide better quality and more comfortable movement allowing our patients to exercise to regain strength, range of motion and muscle mass whose loss is associated with injury, disuse or chronic conditions. Unlike the underwater treadmill, these activities can be done with little financial investment with a bit of ingenuity and creativity. Activities as simple as walking and trotting over different inclines and terrain, walking over cavaletti rails, walking with resistance provided by water, elastic bands, sand, snow, and sit to stand exercises are all exercises that can be incorporated into a dry land rehab program. Many of these activities are essential to a well-directed home exercise program. Stairs, exercise balls and peanuts, orange safety cones, and broom sticks can all be modified and used inexpensively to set up a dry rehabilitation area.

References

1.  Rexing J, Dunning D, Siegel AR, et al. Effects of cold compression, bandaging, and microcurrent electrical therapy after cranial cruciate ligament repair in dogs. Vet Surg. 2010;39:54–58.

2.  Drygas KA, McClure SR, Goring RL, et al. Effect of cold compression therapy on postoperative pain, swelling, range of motion, and lameness after tibial plateau leveling osteotomy in dogs. J Am Vet Med Assoc. 2011;238:1284–1291.

3.  Mueller M, Bockstahler B, Skalicky M, et al. Effects of radial shockwave therapy on the limb function of dogs with hip osteoarthritis. Vet Rec. 2007;160:762–765.

4.  Dahlberg J, Fitch G, Evans RB, et al. The evaluation of extracorporeal shockwave therapy in naturally occurring osteoarthritis of the stifle joint in dogs. Vet Comp Orthop Traumatol. 2005;18:147–152.

5.  Francis DA, Millis DL, Evans M, et al. Clinical evaluation of extracorporeal shock wave therapy for management of canine osteoarthritis of the elbow and hip joint. In: Proceedings of the 31st Annual Conference Veterinary Orthopedic Society; 2004; Big Sky, MT.

6.  Millis DL, Drum M, Whitlock D. Complementary use of extracorporeal shock wave therapy on elbow osteoarthritis in dogs. Vet Comp Orthop Trauma. 2011;24(3):A1.

7.  Pelizzari C, Mazzanti A, Raiser AG, et al. Medium frequency neuromuscular electrical stimulation (Russian) in dogs with induced muscle atrophy. Ciênc Rural. 2008;38:736–742.

8.  Johnston KD, Levine D, Price MN, et al. The effect of tens on osteoarthritic pain in the stifle of dogs. Proc 2nd International Symposium on Physical Therapy and Rehabilitation in Veterinary Medicine; 2002; Knoxville, TN.