Myofascial pain can be an acute or chronic pain disorder and is well recognized in people. It is defined as a condition where pressure on sensitive, hyper-irritable spots located within taut bands in muscle, called myofascial trigger points, or MTPs, causes pain in the muscle and sometimes in seemingly unrelated parts of the body. This is also true for dogs.
Sadly, myofascial pain in dogs is greatly under-recognized and therefore often goes untreated. It is most often diagnosed by careful palpation of skin, subcutaneous tissues that surround the muscles, called fascia, and the muscles themselves. This must be done by someone who has been specially trained to assess myofascial pain in the dog, such as a certified canine rehabilitation therapist. When evaluating, it is important to ensure that the dog is relaxed during the exam. It is therefore necessary to spend enough time massaging and feeling the tissues, during a fear-free evaluation, to determine if a muscle feels tense from anxiety or from pain.
Fortunately, since the emergence of the disciplines of veterinary rehabilitation and sports medicine, there has been much more focus on finding and treating muscle pain and strengthening muscles to address mobility problems.
Signs and symptoms of myofascial pain in dogs may include:
• Trembling or shaking of a limb after exercise
• A twitching of the skin when petting or on deeper massaging
• Difficulty walking, standing, sitting, or difficulty getting comfortable for sleeping
• Muscle tightness, arching of the back, and tightness when trying to stretch and massage any part of the body
• Increased panting, increased thirst, pacing, other signs of chronic pain
How does this pain happen? Muscle pain most commonly follows joint injury or is caused by ongoing joint inflammation, or arthritis. Painful joints cause a dog to shift his weight off the painful leg and onto his other legs and supporting back muscles, resulting in compensatory overuse strain. In addition, muscles atrophy around the painful limb due to disuse of the leg. This can happen in as quickly as two weeks if not using the leg at all due to pain and is seen in varying degrees. Disuse atrophy, combined with myofascial trigger points, produces further muscle weakness and dysfunction in the leg. Pain from a joint or injured muscle, tendon, or ligament will also inhibit muscle firing as a way for the body to protect itself from further use and injury. Thus, atrophy can continue to arise from lack of firing due to the pain as well as due to disuse, creating a viscous cycle. Even when the dog may appear to be putting the leg down to use it, he/she may not be fully engaging the muscles and not strengthening that leg.
Myofascial Pain can also follow nerve injury or dysfunction. Muscles innervated by an irritated or injured nerve can become painful. If you have ever experienced sciatica, you know what this feels like. It is suspected that as much as 80 percent of chronic back pain reported in people is due to myofascial pain and muscle tightness long after an injury has occurred. This explains why controlled stretching, gentle yoga, or Pilates, and other movement therapies significantly help reduce lower-back pain. This is true for dogs as well.
Muscle pain in dogs may also result from overuse arising from repetitive motions, such as repeated ball retrieving on a weak or injured leg; trauma to a muscle; and metabolic and endocrine disorders such as hypothyroidism, Addison’s disease, Cushing’s disease, or diabetes
Overuse muscle disorders can result in muscle injury, commonly defined as muscle strain. (You sprain a ligament, but you strain a muscle). Muscle strain has been defined as acute tearing or stretch
injury of muscles in the
belly of the muscle or at the muscle-tendon junction. For example, the hip flexor muscles, called the illiopsoas, are a commonly injured muscle group but are often missed as it is primarily a diagnosis made by muscle palpation, which can be confirmed only by musculoskeletal ultrasound or MRI and not with X-ray.
Functional muscle disorders arise from either fatigue (muscles cannot keep firing) or neuromuscular disorders (nerves and muscles aren’t communicating), and are without evidence of muscle tear.
Myofascial trigger points and muscle pain in dogs is best diagnosed and treated by a certified canine physical rehabilitation therapist who will can best determine which treatments may help your dog.
As far as recommended treatments, first and foremost, an injured muscle needs to rest, as continued use can further damage the muscle. Muscle pain must be treated before strengthening the muscle with controlled exercise. The following are some of the ways that physical therapy can reduce myofascial pain:
• Acupuncture – dry needling and electro-stimulation — is commonly used to treat MTPs and muscle and nerve pain.
• Sound-wave therapies, such as low intensity extracorporeal shockwave, or fESWT, or therapeutic ultrasound can offer profound and immediate relief of myofascial pain.
• Therapeutic laser, pulsed electro-magnetic field therapy, or PEMF, and transcutaneous electro-neuro stimulation, or TENS, are other treatment modalities used to help reduce muscle pain and tightness.
• Heat applied to tense muscles will relax tight bands of tissue and help with painful MTPs; and swimming or underwater treadmill workouts in water above 80 degrees can relieve pain and greatly improve muscle relaxation, which allows for better muscle strengthening.
• Manual (hands-on) therapies such as gentle massage and joint movement, therapeutic stretching, and chiropractic care help make muscles more elastic and can greatly reduce pain.
• Addition of a muscle relaxer, such as Methocarbomal, is often helpful for myofascial pain, and other medications used for relieving myofascial pain include Gabapentin, Pregabalin, and Amantadine, which help block transmission and perception of pain.
Nutritional supplements such as kelp, which is rich in calcium and magnesium, are especially good for relaxing painful muscles, and supplements such as fish oils or algae, rich in the omega 3 fatty acids DHA and EPA, and herbs such as boswellia or tumeric can also aid in reducing muscle pain by reducing inflammation from damaged muscle tissues.
Significant muscle strain patterns can develop over time due to inadequate pain control and ongoing over-use postural changes.
Ultimately treatment for myofascial pain is to treat the underlying problem. Otherwise, despite intervention, painful muscle strain patterns may soon return, becoming harder and harder to address.
Ilana Strubel, MA, DVM, CVSMT, CCRT, has expertise in integrative veterinary physical rehabilitation, veterinary orthotics and prosthetics, chiropractic care, acupressure, nutrition, and animal behavior consultation. She is certified by the College of Animal Chiropractors, Tall Grass Animal Acupressure Institute, Canine Rehabilitation Institute, and OrthoPets Veterinary Orthotics and Prosthetics and holds a Donald G. Low-CVMA Practitioner Fellowship in Animal Behavior from UC Davis. Learn more about her clinic, A Well Adjusted Pet, in Pacfica at AWellAdjustedPet.com.
Are you a San Francisco Bay Area veterinarian who would like to write an article for the Ask Dr. Dog column, which is authored by guest veterinarians practicing in the Bay Area? Bay Woof is accepting submissions. Send email to Editor@BayWoof.com.
Main article photo by: Photo by Milante-istock