UAC Pathology Services oversees quality assurance for the animal care program. As rodents comprise ~85 percent of the animals used in our facilities, the rodent health monitoring program is essential for the maintenance of rodents that are free of infectious diseases that can adversely affect research through morbidity, mortality, and physiologic and immunologic perturbations.
Given the massive number of rodents maintained in UAC facilities, we utilize a "herd health" approach to assess the infectious disease status for each individual rack of mice (as all are maintained in microisolator caging which prevents cage to cage transmission) and for each room of conventionally housed rodents (rats, hamsters, guinea pigs). Immunocompetent specific pathogen free (SPF) rodents matching the same species being monitored are used as sentinels. Sentinels are obtained from an intramural breeding colony (mice) or purchased from approved commercial vendors (other rodents). Each of these sources are routinely evaluated for the presence of infectious agents with placement of the sentinel animals into rooms containing investigator-owned rodents only after they have been determined to be free of infectious disease. Every week during cage changing each sentinel pan is exposed to soiled bedding from each cage on the rack or in the room. If infectious agents are present in any of the colony animals, it is expected that the sentinel will also become infected.
Three times a year, new sentinel rodents are placed and the sentinel rodents from the previous 4 month exposure are evaluated for the presence of infectious agents. To maximize the cost:benefit ratio, rodents are tested every 4 months for the most common infectious agents (certain viruses, parasites) with annual comprehensive screens for all known infectious agents. Testing procedures vary for each agent, but include gross necropsy, serology (viruses, Mycoplasma), bacteriology (respiratory and enteric pathogens), real-time PCR (Helicobacter sp.), parasitology, and histopathology.
Summary reports of all test results are posted monthly in each facility and on the UAC website. Positive results are immediately reported to the Associate Director and facility Husbandry Coordinator. Investigators are notified and appropriate steps are taken to quarantine the animals and eliminate the disease. Follow-up testing is performed as needed.