We have developed a small animal photography technique to measure the extent of visible lesions on the body in two or three dimensions:
Bazin, N. K. Purohit, G. M. Shah. Comprehensive measurement of UVB-induced non-melanoma skin cancer burden in mice using photographic images as a substitute for the caliper method, PLoS One, 12(2): e0171875 (2017).
This is a technique that allows the progression of lesions to be recorded using conventional photography to measure them later. Measurements on photographs are carried out outside the animal facility and can therefore be performes after the end of an experiment or checked as many times as necessary. Photographs from several viewing angles make it possible to measure the length L, width ℓ and height h of a lesion.