IDENTIFICATION AND RECORDS
Guinea pigs may be individually identified by tattooing the ear with a fine pen type tattooing machine or by applying a numbered ear tag and washer through a hole punched in the ear. The tag should be applied loosely enough so the circulation to the tip of the ear is not compromised.
Ear tag in a guinea pig
Guinea pigs may be temporarily identified by marking the animal’s hair with a broad felt tipped marker or with non toxic dyes. This marking will need to be reapplied as it begins to fade. There are methods available to identify individual animals with implantable electronic devices.