Taking a Horse's Blood Pressure
The blood-pressure cuff is an accurate, but underutilized tool in detecting laminitis. The average horse's systolic reading, which indicates the force of blood pumped from the heart, will remain between 110 and 120. (Diastolic pressure is rarely an indicator of disease in horses.) Early in an episode of laminitis, a horse's blood pressure shoots up by 20 to 30 points or more as blood is forced through the constricted vessels within the hooves. This increase occurs as much as 12 hours before the obvious physical signs of laminitis appear, a small window of time to begin aggressive treatment that may prevent the worst damage.
For this procedure, you'll need a manual pediatric blood-pressure cuff (sphygmomanometer), available at some pharmacies and most medical supply stores. The device we used cost $30.
1. To take a horse's blood pressure, place the cuff under the tailbone at the point where it is least tapered. Be sure to put the bladder of the cuff, where the tubes enter, on the underside of the tail.
2. Use the cuff's Velcro closures to secure it. Make it snug but not too tight so that it exerts about the same pressure that a tail wrap would.
3. Make sure the valve by the bulb is closed and pump the bulb until the pressure reads 160 or greater.
4. Then crack the valve very, very slightly so air leaks extremely slowly. If you let air escape too quickly, you won't be able to get a reading.
5. As the cuff deflates, watch the needle fall. At certain points, it will hesitate before dropping again. Eventually, the needle will hesitate, then bounce upward to a higher reading before dropping again. That bounce is caused by the blood in the underside of the tail pressing against the cuff. The number at which the needle first hesitates before bouncing up again is the horse's systolic blood pressure.