Many people will have heard of the concept of measuring drugs in human hair to expose drug use over time, a technique that is becoming well known and well established in forensic and clinical circles. It is made possible by the fact the hair matrix is inert, so once a drug enters through the blood supply to the follicle, it remains at the same position as the hair grows. This property allows the pattern of drug use of an individual to be deciphered over weeks and months by analysing short segments of hair in sequence.
What is less well known is the application of the same technique to the whiskers of animals. Read more.