What is capillary refill time?
Capillary refill time (CRT) is a simple method to measure the time it takes for a capillary bed to regain colour after pressure has been applied to cause blanching. Capillaries are tiny blood vessels are which are close to the surface of the skin that gives it its pink colour. The purpose of capillary refill time is to assess blood flow through peripheral tissues (known as peripheral perfusion).
How do I check the capillary refill time on my cat?
The best place to check the capillary refill time is on your cat’s gums.
- Lift the cat’s upper lip and press the flat of your finger against the gum tissue
- Remove the pressure and you will see a white mark on the gum where your finger was placed
- Time how long it takes for the pink colour to return to the white spot
- In a healthy cat, it should take around 1 – 2 seconds to return to pink
What is the normal capillary refill time in cats?
Capillary refill time
|1 to 2 seconds||Normal|
|2-4 seconds||Moderate to poor|
|> More than 4 seconds||Emergency|
|< Less than 1 second||Emergency|
Prolonged capillary refill is the result of blood is not flowing adequately due to vasoconstriction which occurs when there is low circulating blood volume and can be caused by shock, dehydration or heart disease.
Rapid capillary refill time under 1 second is suggestive of a hyperdynamic state (abnormally increased circulatory volume) and vasodilation and is associated with heatstroke, hyperthermia and systemic inflammation.
Will checking the capillary refill time cause discomfort to my cat?
No, it is not uncomfortable at all.