Capillary Refill Time - CRT

Capillary Refill Time (CRT) is the time it takes for blood to return to blanched tissues in the gums. This is an indicator of the rate of blood circulation.

To check your horse or pony's CRT lift up the upper lip and firmly press with your thumb against the gums for 2 seconds to create a white mark. This white mark should return to the normal pink colour within less than 2 seconds after releasing the pressure.

If the CRT takes longer than 2 seconds, the horse or pony may have shock and you should seek the advice of your vet.