Shock Wave Therapy for Dogs
This new form of therapy offers arthritis pain relief for dogs using sound waves.
At SGFA we have been performing ESWT since 2008 with a success rate of 90%. Our cases have included: bicipital and Achilles tendonitis, DJD of the hips and elbows, and cervical and lumbo-sacral pain. To date all cases have received only one treatment which has been performed on an outpatient basis.
About Shock Wave Therapy for dogs
Shock waves are high-energy focused sound waves generated outside the body that can be focused at improvement in a majority of animals treated, but this treatment is still in the experimental stage, and results are not always consistent.
Small animal practitioners interviewed in 2003 reported that approximately 70 percent of their patients demonstrated a remarkable response to treatment. Another 15 percent exhibited improvement that was not as significant as the first group. Some of these may improve further with a second treatment. About 15 percent show no improvement. Shoulders, backs, and hips seemed to respond best to ESWT, while treatment of knee injuries had the least response.
How does it work?
Shockwave is defined as a Sonic Pulse characterized by high energy acoustic waves with a high peak-pressure (500 bar). It has a short lifecycle (10 ms) and fast pressure rise (< 10 ns) with a broad frequency spectrum (16 Hz-20 MHz). The pulse energy needs to be focused in order to be applied where treatment is needed.
ESWT devices generate a series of focused high-pressure acoustic pulses (sound waves) that travel from the probe through the skin and soft tissue. When the waves meet tissue interfaces of different densities, such as where soft tissue, tendons, ligaments, cartilage, and bone meet, the energy contained in the shock waves is released and interacts with the tissue, producing both mechanical and cellular effects.
The shock waves appear to relieve pain and stimulate healing within the injured tissue, although the mechanism for these effects is unclear. Researchers believe may have to do with depletion of neuropeptides that lead to the sensation of pain and can contribute to the inflammatory response.
Shock waves do not appear to slow the progression of osteoarthritis, but rather reduce the pain associated with it. ESWT devices consist of a box that generates the waves and a wand (probe) that is used to target the waves to specific spots.
How shock wave therapy is performed
A physical exam is required to diagnose a musculoskeletal disorder and to rule out neurological disease that cannot be treated with to ensure the dog is healthy prior to anesthesia.
Discomfort during treatment can range from mild to severe depending on the intensity used, so animals are usually heavily sedated or given short-acting general anesthesia. Low-intensity treatment may be done under light sedation. The machine that generates the pulses can be quite loud, which may be frightening to the patient.
It takes only a few minutes to treat each site. The area to be treated must be shaved and a gel applied to ensure transfer of energy from the probe head to the patient's tissues, as any air between the probe and the skin will interfere with the mechanism. The energy level used and the number of pulses delivered is based on the location, type, and severity of the disorder.
Protocol varies, but commonly from one to four treatments are done, two weeks to a month apart. Improvement may be seen right away, or it may take a few weeks to see the full effects of the treatment. The process may need to be repeated around once a year.
ESWT is generally considered safe, though high-intensity or prolonged treatment (beyond 1,000 pulses) might be capable of damaging tissue or bone. The energy intensity matters more than the number of pulses. It is possible that the analgesic (pain-relieving) effect can lead to overuse, which would make injury more likely, so it's important to moderately restrict activity as needed for a few days following treatment.
ESWT is not recommended for dogs with clotting disorders due to the potential for bruising. Dogs that are immune-compromised may not respond as well to therapy, which is thought to rely on the body's own immune system for healing. With proper use, side effects are insignificant, limited to some bruising of the skin where the pulses are applied if bubbles are present or good contact with the probe cannot be achieved.
Cost of treatment
Treatment with ESWT will commonly run around $600 per site, plus the costs for exam, tests, and anesthesia or sedation.