Based on the article Cold & Heat Therapy, by Patrick Herbots, DVM
Equine Bodywork Practitioner uses a variety of techniques for equine rehabilitation, including cold and heat therapy. It helps to optimize function and reduce any existing disability.
Typically, this therapy works on a 1:3 cold to heat ratio. First, apply cold for one minute, then heat for three minutes, for a duration of 20 minutes. This causes the vessels to alternately constrict then dilate, creating a vascular pump.
COLD TREATMENT
Cold treatment reduces inflammation by decreasing blood flow. Apply within 48 hours after an injury.
General EFFECT: Vasoconstriction, Hypo metabolism, Decreased nerve conduction velocity, Anti-inflammatory effect + analgesia, Influences swelling, Cold decreases muscle-spindle sensitivity to stretch thereby reducing muscle spasm, Increased collagen stiffness.
INDICATIONS: Musculoskeletal trauma, Pre/post operatively, Pain secondary to muscle spasm, Limitations to motion secondary to pain and edema.
C/I: Cold hypersensitivity; Decreased sensation; the animal with this condition may be at risk of tissue damage as it may be unable to sense discomfort; Previous frost bite to the tissues; Over an area of compromised circulation.
CONSIDERATIONS:
TIME OF APPLICATION: begin the initial application as soon as possible. The first 24-48 hrs are key.
LENGTH OF APPLICATION: Optimum duration is from 20 to 30 min. Repeat cold therapy every 4-6 hrs within the first day. Apply ice for approximately 15-30 min at a time until heat, swelling and pain are reduced. Cold application for more than 30 min can have detrimental effects, including neuronal and cellular damage.
ANATOMICAL SITE: the skin cools first, followed by the subcutaneous tissue. Joints cool more slowly than muscles.
CONDITION OF THE TISSUE: Not drop the core temperature of the tissues below 15°C.
COMPRESSION: may be combined with cold to enhance its effectiveness. Compression should be applied in a distal to proximal direction. Pressure increases the efficiency of cold delivery.
EFFECTS:
LOCAL VASOCONSTRICTION: Cryotherapy causes small blood vessels on the body surface to constrict, it may help reduce haemorrhage and edema. Controls bleeding and reduces the release of chemical mediators.
LOCAL VASODILATATION: If cold treatment cools local tissues to 18°C for long enough to interfere with sympathetic nerve conduction, vasodilatation may occur. When tissue temperature falls below 18°C, the initial reduction of blood flow is followed by a compensatory increase in blood flow (due to dilation of muscle blood vessels). Reflex vasodilatation was not recognized after 30 min of cold therapy at 4°C, when applied to the equine metacarpus. The “Hunting” reaction occurs at intramuscular temperatures of 7 to 10°C.
HYPOMETABOLISM: The decrease in inflammatory response due to decreased tissue metabolism, which limits secondary tissue damage due to hypoxia.
DECREASED NERVE CONDUCTION VELOCITY: Cold impairs the conduction of afferent sensory input resulting in pain reduction.
PAIN-ANALGESIA: 3 min duration of analgesia after ice massage. Analgesia occurs at surface temperatures of 10 to 15°C.
ANTI-INFLAMMATORY EFFECTS: cold reduces inflammation by inhibiting histamine, neutrophil activation, collagenase activity and synovial leucocytes.
EDEMA: The application of cold therapy is followed by a compression wrap, to eliminate further edema formation.
REDUCED MUSCLE SPASM: Cold decreases activity of the muscle spindle, which in turn decreases muscle spasticity.
MODALITIES TO USE: Cold Water Hose; Tub, whirlpool, turbulated boot; Commercial cold packs; Iced towel, gel wraps; Ice massage; Home made ice packs. Ice which is applied at a temperature of 0°C, has the potential to injure tissue. Use a damp cloth or sheet cotton as a buffer, between the ice pack and the horse’s skin, to protect the tissue and dissipate the cold.
CONTINOUS COLD THERAPY: Continuous cold application offers the additional advantage of controlling the vasoconstriction/ vasodilatation cycle. Continuous cold therapy from 7 to 10°C reduces pain, decreases analgesic intake, and decreases swelling.
