Investigation of appropriate sanitization frequency for rodent caging accessories: evidence supporting less-frequent cleaning.

The Guide for the Care and Use of Laboratory Animals states that sanitization of caging accessories (for example, filter tops and wire-bar lids) should be done every 2 wk. In this study we tested the hypothesis that organic contamination measured by the presence of ATP associated with organic material (measured with luciferase test swabs) and the number of bacterial colony-forming units (as determined by use of replicate organism detection and counting plates) on caging accessories did not differ significantly at 2 wk versus several months of use. The study evaluated 4 groups: mouse and rat ventilated and static wire-bar cages with or without filter tops (n = 10 per group).

Cross-fostering in combination with ivermectin therapy: a method to eradicate murine fur mites.

A colony of mutant mice with sickle cell anemia was infested with the fur mites Myocoptes musculinus and Myobia musculi. Pups of sickle-cell phenotype obtained by cesarean section prior to natural birth were of such poor vigor that none survived the combined insults of delivery by hysterectomy and cross-fostering. Consequently, surgical rederivation, the most reliable means of mite eradication, was not an option.

Long-term results of dietary fenbendazole to eradicate Syphacia muris from rat colonies.

The pinworm Syphacia muris was eradicated from rats after treatment with fenbendazole-medicated chow (150 ppm) and without environmental decontamination for > 54 months. However, this regimen was successful only when the treatment was delivered and efficacy monitoring was done by personnel of the institutional animal resources program. The same pinworm elimination program failed 7 to 24 months after the cessation of treatment in a satellite colony in which animal care, including provision of medicated diet and sample collection for efficacy monitoring, was provided by research personnel.

High Mortality in Zebrafish (Danio rerio).

A group of 100 adult zebrafish were housed in a new system at a stocking density of 20 fish per tank. Four weeks after arrival, 15 fish presented with petechial hemorrhages and ulceration on the surfaces of the skin. Samples of the fish were collected for histopathology, fungal culture, and bacterial culture and sensitivity.