Physical Rehabilitation for Dogs Part 3: Ultrasound
Like with electrical stimulation, ultrasound therapy is a physical rehabilitation modality that has been used in human PT for many years, and is now becoming common in canine rehabilitation programs. I remember back almost 10 years ago when I had my first troublesome injury, a strained Achilles tendon, (actual diagnosis was Achilles tendinosis, which means that the collagen fibers in the tendon were in disarray!), and I was first introduced to ultrasound therapy. Although it was hard to tell if it was helping me in my recovery, I ended up purchasing a home unit so I could treat myself whenever I wanted.
Ultrasound machines are available in virtually all physical rehab shops (for humans) and they are utilized in canine rehab centers as well. The reasoning behind using ultrasound for rehab is the same for humans and dogs. Primarily, ultrasound allows for deep, penetrating heating of the target area in a way that spares the outer tissues (i.e., skin) from damage.
Appropriate Usage of Ultrasound Therapy
Ultrasound works very much like heat therapy, with the added benefit that it can penetrate deeper than topical heat. Like heat therapy, ultrasound therapy can improve blood flow, decrease muscle spasms, promote mobility, and reduce pain. As it relates to tendons, (and Achilles tendons specifically), one study showed that ultrasound therapy increased the tensile strength and energy absorption capacity of Achilles tendons in rabbits (http://www.ncbi.nlm.nih.gov/pubmed/2686717). Perhaps I was right to purchase my own unit?
Effective Ultrasound Therapy for Dogs
Treating a dog with ultrasound therapy is similar to the way that a person would be treated. Gels are used on the target area to ensure that the ultrasound is properly ‘coupled’ with the tissue and delivered efficiently. The head of the unit should be slowly and consistently moved across the treatment area to ensure that any one spot doesn’t become over heated. The head should be as close to flat as possible on the target area so that the sound is delivered deep into the tissue as opposed to tangentially.
Lastly, ultrasound will not be as effective if there is a lot of hair on the target area. For this reason, dogs will likely need to be shaved (as will some humans) at the spot of the injury in order for the therapy to be effective.
Ultrasound should not be used on infected or bleeding areas, or malignancies. It is not recommended as course of treatment for bone fractures, including stress fractures.