c/o Johnson and Johnson Medical Ltd., Coronation Road, Ascot, Berkshire SL5 9EY, UK.
Near infrared spectroscopy of pedal haemodynamics and oxygenation in normal and laminitic horses
Article first published online: 23 APR 2010
© 1995 EVJ Ltd
Equine Veterinary Journal
Volume 27, Issue 6, pages 465–470, November 1995
How to Cite
HINCKLEY, K. A., FEARN, S., HOWARD, B. R. and HENDERSON, I. W. (1995), Near infrared spectroscopy of pedal haemodynamics and oxygenation in normal and laminitic horses. Equine Veterinary Journal, 27: 465–470. doi: 10.1111/j.2042-3306.1995.tb04428.x
- Issue published online: 23 APR 2010
- Article first published online: 23 APR 2010
- Received 27.10.94; Accepted: 1.4.95
- near infrared spectroscopy;
- pedal haemodynamics
The present study applies near infrared spectroscopy (NIRS) to the haemodynamics of the pedal circulation in normal and laminitic horses. NIRS is a noninvasive technique which uses changes in light absorption at 4 wavelengths to provide information on the changes in cytochrome aa3 (cyt aa3) reduction-oxidation (redox) status, and changes in the tissue concentration of oxyhaemoglobin (O2Hb), deoxyhaemoglobin (HHb) and therefore total haemoglobin (tHb). Other studies have shown NIRS to be sensitive to changes in tissue oxygenation and perfusion in human cerebral and limb circulation. In this study, the NIRS sensor was applied to the dorsal surface of horses' hooves. Normal and laminitic animals (acute and chronic) were subjected to manoeuvres (cuff tourniquet; digital vessel occlusion at the palmar surface of the pastern; lifting of contralateral limb) predicted to change pedal haemodynamics. The procedures produced changes in pedal haemodynamics and oxygenation, which were similar to those observed in the ischaemic/reperfused human forearm. Laminitic differed from normal horses: return of HHb to baseline was slower and the change in cyt aa3 more rapid than normal in cases of chronic laminitis, taken to indicate reduced O2 stores as a result of compromised basal perfusion. In acute laminitis, baseline values did not fluctuate following any of the manoeuvres, suggesting haemostasis in the diseased hoof. NIRS is a useful noninvasive method to assess pedal vascular function in normal and laminitic horses.