Evaluation of a Synthetic Bedding Substrate for Mice (Mus musculus).

This study compared a synthetic bedding substrate (SBS), which has the potential to be a particulate-free animal bedding system, with the standard woodchip bedding. The objective was to demonstrate that the SBS is habitable for mice and reduces particulates to levels that would not contaminate the eye or potentially induce ocular (corneal) injury. Newly weaned mice were placed in either standard woodchip bedding or SBS. All mice were monitored regarding overall health (appearance, food and water intake, natural behavior, clinical signs, and provoked behavior) to verify their ability to adjust to the bedding. At 8 to 10 wk of age, the mice underwent slit-lamp evaluation for ocular (corneal) abnormalities. Results showed significant differences in body weight and overall health between bedding groups. The incidence of ocular abnormalities did not differ significantly between groups. We conclude that, without modifications and more testing, SBS is not a favorable bedding for mice, and results were inconclusive regarding its use as a bedding to preclude ocular contamination.

Plasma Concentration of Meloxicam in Pediatric Rats.

In this study, we compared the plasma concentrations of meloxicam in pediatric rat pups (ages: 7, 14, 21, and 28 d) with those of young adult rats. Adult rats received 1.34 mg/kg SC meloxicam to determine the target peak plasma concentration (Cmax) for comparison with the pediatric animals. Pediatric rats received 1.34 mg/kg SC meloxicam, and in all age groups, Cmax met or exceeded that in adults (11.5 ±2.7 µg/mL). Plasma concentrations were similar between male and female pups within age groups, and peak plasma concentration was achieved more rapidly in rat pups than adults. The analgesic efficacy of this dose was not evaluated in this study.