Etiology:  Insufficient environmental humidity (<20%), artificially increased temperature and drafts predispose rats to developing this condition.  Other physiological factors (age, hydration, nutritional status, and genotype) can also be involved.

Incidence:  The incidence of ringtail is uncommon.

Clinical Signs:  Annular constriction of the tail is observed in young (suckling and weanling) rats.  Necrotic tails may slough.

Diagnosis:  Diagnosis is made via clinical signs and history of low environmental humidity.