The Dental Tissues of Wild and Laboratory-raised Hibernating and Non-hibernating 13-lined Ground Squirrels

¹ Departments of Bacteriology, Stomatology, and Physiology, State University of Iowa, Iowa City, Iowa

Periodontal tissue changes were observed much more frequently in non-hibernating and hibernating ground squirrels maintained in the laboratory for 36 months than they were in wild ground squirrels captured in their natural environment.

The principal changes observed in laboratory-raised ground squirrels included extensive impactions of debris between the teeth, loss of approximately 50 per cent of the crowns of the lower posterior teeth, and severe inflammatory reactions around retained roots.

Hibernating (laboratory-raised) ground squirrels showed pathologic disturbances similar to those observed in the non-hibernating animals, except that extensive inflammatory reactions, crevicular epithelial hyperplasia, pocket formation, and ulcerated papillae were observed approximately twice as frequently in the lower jaws of hibernating squirrels as in the non-hibernating animals.

Significantly more crowns were missing from the lower jaws of the non-hibernating, animals than from the lower jaws of the hibernating ground squirrels.

Pathologic changes in the periodontium were observed more frequently in the lower jaws than in the upper jaws in all three groups of ground squirrels, and they were observed with equal frequency in both sexes.

No significant differences were observed between the incisor lengths of non-hibernating, hibernating, and wild ground squirrels.

Only one carious lesion was observed in all three groups of ground squirrels.

The micro-organisms comprising the oral floras of non-hibernating and hibernating ground squirrels were similar.

This study failed to provide unequivocal evidence that hibernation per se had either an adverse or a protective affect on the dental tissues of the ground squirrels.