A simple alopecia scoring system for use in colony management of laboratory-housed primates

Abstract

Background: Alopecia in captive primates continues to receive attention from animal care personnel and regulatory agencies. However, a method that enables personnel to reliably score alopecia over time and under various conditions has proven difficult to achieve.

Methods: The scoring system developed by the behavioral and veterinary staffs at the Washington National Primate Research Center (WaNPRC) uses the rule of 9s to estimate the percentage of the body affected with alopecia (severity) and how the alopecia presents itself (pattern). Training and scoring can conveniently be managed using photographic images, cage-side observations, and/or physical examinations.

Results: Personnel with varying degrees of experience were quickly trained with reliability scores ranging from 0.82 to 0.96 for severity and 0.82 to 0.89 for pattern using Cohen's κ.

Conclusions: This system allows for reliable and consistent scoring across species, sex, age, housing condition, seasons, clinical or behavioral treatments, and level of personnel experience.

Keywords: alopecia; alopecia scoring; colony management; hair loss; hair pulling; macaque; molt; rule of 9s; self-injurious behavior; trichotillomania.

Fig. 1

Generic primate body illustrating the ‘rule of 9s’. Note that the tail is not shown but counts for 1% of the total score.

Fig. 2

Alopecia severity score 2 (four body parts affected – head, upper back, L lower leg, R lower leg).

Fig. 3

Alopecia severity score 4 (nine body parts affected – head, L arm, R arm, L upper leg, R upper leg, L lower leg, R lower leg, upper back, lower back).

Fig. 4

Example: Diffuse alopecia pattern.

Fig. 5

Example: Patchy alopecia pattern.

Fig. 6

Example: Bare alopecia pattern.