The Comparative Medicine Unit (CMU) conducts health monitoring of rodent breeding colonies four times per year and non-breeding colonies two times per year. Samples are collected from three – five animals in each occupied housing room for each round of testing. Sentinel animals are obtained directly from resident colonies OR are acquired as specific pathogen free animals (mice: Crl:CD-1(ICR)BR; rats: CDIGS) and housed for a minimum of six weeks in the room before testing. Resident sentinels are at least six weeks old at the time of evaluation. Acquired sentinel animals are generally twelve to sixteen weeks of age. Soiled bedding from random cages in the housing room is placed into the cages of acquired sentinel animals at each cage change interval.

Using serum pooled from all sentinel animals in a room, mice are serologically tested for common adventitious pathogens as listed at the species link given above.

Pooled fecal samples from the sentinels are evaluated by fecal floatation exam. Perianal tape tests from individual animals are examined for evidence of intestinal parasites. A gross post mortem examination is conducted. More comprehensive evaluations are performed as needed or upon request.

Helicobacter testing: In December 2001 six out of eight mouse housing rooms tested were found to be positive for H. hepaticus, H. bilis, and/or H. typhlonicus. At the present time, ongoing testing for Helicobacter is not performed. Please contact the CMU if there are questions concerning Helicobacter or if it is necessary to maintain animals free of these bacteria.

Helicobacter species, particularly H. hepaticus, have been associated with several pathologic states in mice including inflammatory bowel disease, hepatitis, and an increased incidence of hepatic neoplasia.

Using serum pooled from sentinel animals in a room, rats are serologically tested for common adventitious pathogens as listed at the species link given above.

Pooled fecal samples from the sentinels are evaluated by fecal floatation exam. Perianal tape tests from individual animals are examined for evidence of intestinal parasites. A gross post mortem examination is conducted. More comprehensive evaluations are performed as needed or upon request.

Using serum from one or more animals, guinea pigs are serologically tested for common adventitious pathogens as listed at the species link given above.

Pooled fecal samples from the sentinels are evaluated by fecal floatation exam. A gross post mortem examination is conducted. More comprehensive evaluations are performed as needed or upon request.

Rodents are housed in conventional shoebox style cages or static microisolation cages (autoclaved or not). Conventionally housed animals and those housed in nonsterile microisolation cages are provided with filtered (Aqua Pure filter #AP117) tap water in water bottles and LabDiet® Formulab Diet #5008 food offered ad libitum. Animals housed in sterile microisolation cages are provided with autoclaved filtered water in water bottles and fed autoclaved (LabDiet Autoclavable ProLab RMH 3500) rodent chow or irradiated (LabDiet ProLab® Isopro RMH 3000) chow. Other foods, including supplements, may be offered depending upon the specific needs of the animals or the research protocol under which they are used.

Rodent cages are routinely changed once weekly or more often as needed based upon experimental or animal requirements. Conventional cages and nonsterile microisolation cages are changed in the housing room in which they are located. Sterile microisolation cages are removed to a centrally located changing room where they are changed in a laminar flow workstation that provides HEPA filtered airflow over the work surface. All opening of autoclaved cages and handling of the animals housed in them is performed in this hood using aseptic technique.

Rodents entering the CMU must be acquired from suppliers identified on the CMU Approved Vendor List OR undergo quarantine in Horsfal Isolation cubicles and pathogen testing before entry into the facility.

ALL acquisitions of animals from suppliers not identified on the approved vendor list MUST be approved by the CMU Director before arrangements are made to ship animals. Please note that the pathogen status of some animals may preclude their housing at Northeast Ohio Medical University.

Quarantined animals are housed in microisolation (sterile or nonsterile – depending upon the nature of the animals and the intended housing location in the CMU) cages and evaluated using the same testing strategy as for the routine rodent health monitoring. Additional testing may be required depending upon the source of the animals and their health report history.