Effects of external thermal manipulation on laminar temperature and perfusion scintigraphy of the equine digit

Authors: Sargeant J, Worster AA, Erb JH, Hoskinson JJ, Gaughan EM
Publication: New Zealand Veterinary Journal, Volume 48, Issue 4, pp 111-116, Aug 2000
Publisher: Taylor and Francis

Animal type: Horse, Livestock
Subject Terms: Hoof/claw, Limb - lower, Locomotor, Disease/defect, Treatment/therapy
Article class: Scientific Article

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Abstract: AIMS:  To assess the effects of external thermal manipulation on the soft-tissue and vascular perfusion of the equine digit using nuclear scintigraphy and documented tissue temperatures.
METHODS:  Six horses were used in a randomised crossover design. Each horse was treated with external heat (47°C) or external cold (4°C) applied to a digit for 30 minutes. The opposite front foot was untreated and used for control measurements. Nuclear scintigraphy was performed before, during, and after therapy to assess vascular and soft-tissue perfusion to the digit in response to therapy. Dorsal hoof wall laminar-tissue temperatures were recorded before, during, and after therapy using a thermistor.
RESULTS:  Treatment with topical cold therapy significantly decreased soft-tissue perfusion of the digit to 80.5% of the pre-cooled values. Conversely, the application of external heat significantly increased soft-tissue perfusion of the digit 25.1% above the pre-heated values. Vascular perfusion showed similar, but not statistically significant trends. External cold application to the digit caused a significant mean decrease in laminar-tissue temperatures of 11.6°C during therapy, while external heat application to the digit caused a significant mean increase in laminar-tissue temperatures of 3.9°C.
CONCLUSION: The external application of heat and cold to the normal equine foot could effectively alter soft-tissue perfusion and laminar-tissue temperatures within 30 minutes of treatment. The application of hot water and ice water to the digit was a safe, well-tolerated, and economical therapy.
CLINICAL RELEVANCE: Cooling the foot could decrease enzymatic reactions associated with laminitis, and warming could increase local perfusion when desired.
KEY WORDS: Hot therapy, cold therapy, vascular perfusion, soft-tissue perfusion, digit, laminar temperature, horse.

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