Effectiveness of the Glass Bead Sterilizer for Sterilizing Surgical Instruments.

Survival rodent surgery requires the use of sterile instruments for each animal, which can be challenging when performing multiple surgeries on batches of animals. Glass bead sterilizers (GBS) are widely considered to facilitate this practice by sterilizing the tips of the instruments between animals. However, other disciplines have raised questions about the efficacy of the GBS, especially when used with surgical tools that have grooves or ridges that may contain organic debris. In this study, we evaluated the efficacy of the GBS to sterilize instruments commonly used in rodent surgery by intentionally contaminating a selection of instruments with a standardized bacterial broth inoculated with Staphylococcus aureus and Escherichia coli. As expected, a simple ethanol wipe was ineffective in sterilizing instruments in all treatment groups. An ethanol wipe followed by GBS was effective in sterilizing 82.5% (99 of 120) of the instruments. Our study suggests that the GBS may not be effective for consistent sterilization of surgical instruments.

Evaluation of Treatment Options for Ulcerative Dermatitis in the P Rat.

Rotational outbred adult rats, phenotypically selected to prefer drinking alcohol ("P" rats) frequently present with selfinflicted wounds and ulcerative dermatitis, similar to that seen in C57BL/6 mice. Historically, veterinary interventions used to address this clinical condition have included triple antibiotic ointment (TABO), Columbia wound powder (CPW), nail trims, or plastic tubes that allow affected animals to hide. More recent studies have suggested that nail trims are the most successful intervention in mice, but this has not been evaluated previously in rats. In this study, we evaluated nail trims in rats and also tested whether placing a pumice stone in the cage would reduce the need for nail trims to reduce self-inflicted wounds. Our hypothesis was that interacting with the pumice stone would dull/trim the rats' nails without causing stress or illness and allow the wounds time to heal. We used 66 P rats that were assigned to 1 of 6 treatment groups (pumice stone, TABO, CWP, huts, nail trims, and an untreated control group) of 11 rats each. Rats were transferred to this study from a colony of experimentally naïve animals that had evidence of dermatitis. The wounds were photographed and measured for 12 wk at 2 wk intervals. At the end of the study, representative skin samples from the site of the wound were collected for histopathologic evaluation of inflammation. Our data showed no significant differences in the inflammation scores. The rats treated with nail trims healed significantly more often than did all of the other treatment groups. This suggests that nail trims are the most effective intervention for treating self-inflicted wounds in P rats.