Heat therapy increases blood flow, increases blood vessel permeability and increase cellular chemical reactions. Heat stimulates inflammation and invigorates wound healing. Heat relieves pain relaxes ligaments and tendons, decreases muscle tension and spasms. Heat can be applied using hot packs, heat lamps, warm towels, warm-water blankets, therapeutic ultrasound, laser therapy, warm-water baths, and hydrotherapy units. Heat can be applied for 15 to 20 minutes two to four times a day. It should be used after post injury swelling as subsided which is usually 24 to 48 hours after injury or surgery. Heat therapy is effective only at a certain range of temperatures (104 – 113°F). Below which it is not effective and above which it can be harmful.
- Increased circulation
- Pain Relief
- Increased tissue relaxation
- Decreased muscle spasm
Hyperthermia stimulates the same nerves of the skin as TENS and Acupuncture resulting in activation of the Gate Control Theory of Pain. This theory postulates that activating a series of nerve fibers in the skin can inhibit other nerve fibers traveling up the spinal cord to the brain. Active stimulation provided by heat therapy reduces pain sensation. This stimulation also causes the release of opioids from the spinal cord and brain. The combined effect of decreased pain, increased circulation, and earlier mobility result in improved healing.
Hot packs are the most effective mode for applying heat. They include many forms from canvas bags filled with cracked corn beans, silicate gel or other inert materials; electric heating pads, damp microwaved towels; or circulating water blankets. Infrared lamps give off heat and can be used for heating larger areas of the body, they should be positioned 15 to 24 inches away from the pet. Any form of heat should be tested by placing your hand under the heat lam or hot pack for several minutes to see if it is too hot. A pet will try to move away from a heat source that is too hot. Heat therapy should be used with caution in obese pets, pets with poor circulation or poor heart function.
Pets with Intervertebral Disc Disease (IVDD) can benefit from heat therapy 72 hours after the event or surgery. Localized heat to the area of concern should be applied for 15 to 20 minutes four times a day. Massage therapy and passive range of motion exercise is good during and after the heat therapy.