Gavage-Needle Voluntary Consumption Administration of a Dose-Specific Measure to Mice (Mus musculus)

Orogastric gavage is a common technique used to administer test articles to rodents with risks ranging from increased stress to death of the animal. In this study, we propose a novel technique to administer treatments to mice for voluntary consumption through a plastic gavage needle: gavage-needle voluntary consumption (GVC) with a sweetened condensed milk carrier. GVC was successful at orally dosing mice in 95.0% (n = 459) of 483 total GVC opportunities. BALB/c mice (n = 61 [27 males/34 females] for analysis) were randomized into 8 intervention-treatment groups with 2 treatment allocations. Mice habituated to the GVC technique in less than 5 d and continued to consume the condensed milk with or without capromorelin for a 3-d treatment period that commenced after receiving their assigned interventions. The GVC technique allowed for efficient transition to orogastric gavage when the treatment was not consumed in 3.8% (n = 7) of 183 GVC attempts in the treatment period, thereby ensuring that every mouse received its treatment. The proportion of mice that consumed their treatments voluntarily was not affected by the intervention the mice received prior to the treatment period but was affected by the addition of the treatment article capromorelin. It is recommended to consider the GVC technique as a replacement and refinement to oral gavage when orogastric administration of treatments to mice is required.