A comparison of seven methods for continuous therapeutic cooling of the equine digit.
BACKGROUND
Digital hypothermia may be effective for laminitis prophylaxis and therapy, but the efficacy of cooling methods used in clinical practice requires evaluation.


OBJECTIVE
To use hoof wall surface temperature (HWST) to compare several cooling methods used in clinical practice.


METHODS
Experimental crossover design with a minimum washout period of 72 h.


METHODS
Seven cooling methods (commercially available ice packs, wraps and boots) and one prototypical dry-sleeve device were applied to a single forelimb in 4 horses for 8 h, during which HWST of the cooled forelimb and the uncooled (control) forelimb was recorded hourly. Results were analysed descriptively.


RESULTS
The median (range) HWST from 2-8 h was lowest for the ice and water immersion methods that included the foot and extended proximally to at least include the pastern: 5.2°C (range: 4.8-7.8°C) for the fluid bag and 2.7°C (2.4-3.4°C) for the ice boot. An ice boot that included the distal limb but not the foot resulted in a median HWST of 25.7°C (20.6-27.2°C). Dry interface applications (ice packs) confined to the foot only resulted in a median HWST of 21.5°C (19.5-25.5°C) for the coronet sleeve and 19.8°C (17.6-23°C) for a commercial ice pack. For the dry interface applications that included the foot and distal limb, the median HWST was much higher for the ice pack device, 19.9°C (18.7-23.1°C), compared with the perfused cuff prototype of 5.4°C (4.2-7°C).


CONCLUSIONS
Immersion of the foot and at least the pastern region in ice and water achieved sustained HWST <10°C as did a prototype perfused cuff device with a dry interface. Variation between cooling methods may have a profound effect on HWST and therefore efficacy in clinical cases where laminitis prophylaxis or therapy is the goal.
University of Queensland, Gatton, Australia.
A W
AW
van Eps
New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, USA.
J A
JA
Orsini
D000818:Animals; D003080:Cold Temperature; D018592:Cross-Over Studies; D017679:Cryotherapy / Q000379:methods / Q000662:veterinary; D005552:Forelimb; D006724:Hoof and Claw / Q000502:physiology*; D006736:Horses; D007053:Ice
D007053:Ice
cryotherapy; hoof; horse; hypothermia; laminitis