Measurement of transepidermal water loss from clipped and unclipped anatomical sites on the dog



Objectives  To establish a standardised clipping method for the measurement of transepidermal water loss (TEWL) with a VapoMeter® in Beagle dogs and to identify the optimal anatomical site for TEWL measurement.

Procedure  TEWL values obtained from skin sites on five healthy Beagles clipped using two different blade angles (standard vs non-standard) were compared. TEWL values for 48 h were also obtained from seven different anatomical sites that had differing hair density. The hair was clipped in the intensively haired anatomical sites (head, lower and upper back and tail), but not clipped in the sparsely haired sites (ear, inguinal region, footpad).

Results  The TEWL values for the standard and non-standard clipping sites were 6.3 ± 1.31 and 27.2 ± 1.11 g/h/m2, respectively. We found the upper back among the clipped sites was the most appropriate site for TEWL measurement over 48 h after clipping, whereas among the unclipped sites the ear was the most appropriate, because the TEWL values from those anatomical sites had the least fluctuation and were less affected by movement.

Conclusion  The clipping method and anatomical site should be standardised in order to minimise the experimental variation in TEWL measurement in dogs.