What does a CRT (capillary refill time) reading of less than 1 second or greater than 3 seconds indicate?

A capillary refill time (CRT) reading that falls below 1 second or exceeds 3 seconds is indicative of an abnormal range. Capillary refill time is a vital clinical parameter that helps assess peripheral perfusion and overall circulatory status in canines. The typical CRT should be around 1 to 2 seconds, representing adequate blood flow to the capillary beds.

When CRT is shorter than 1 second, this can be a sign of hyperperfusion or an overactive cardiovascular response, while a reading greater than 3 seconds often suggests poor peripheral perfusion due to issues such as shock, dehydration, or other circulatory problems. Therefore, both extremes of CRT should be closely examined as they are potential indicators of underlying health issues, confirming that the reading indeed reflects an abnormal range. Monitoring CRT is crucial for ensuring the dog’s health status is properly evaluated and any necessary interventions can be implemented promptly.