Animal health management and hygiene

In recent decades, the microbiological status of animal colonies, especially mice and rats, has been highly improved due to the amelioration of animal facilities, house caging systems, experimental procedures, and health moni- toring programs. The microbiological status of experimental animals can dramatically influence the animal welfare, the robustness, and the reproduc- ibility of research results. The Federation of European Laboratory Animal Science Associations (FELASA) has published several updated editions of recommendations for rodent health monitoring (1994, 1996, 2002, and 2014). These recommendations are intended to harmonize health monitoring pro- grams and to standardize the microbiological quality of the animals to ensure reproducible results. Microorganisms can influence experimental results even if symptoms are not detected since many pathogens cause subclinical diseases. Subclinical disease may perturb biological parameters (behavior, growth rate, organ weight, immune response), and they may generate interferences with research. Symptom manifestations depend on many variables such as bacterial or viral infectious strains, the host immune status, the simultaneous presence of other pathogenic or opportunistic microorganisms, and the genetic back- ground/mutation. Some pathogen of laboratory animals (LAs) can also infect humans (zoonoses). For all these reasons, all institutions should establish a health monitoring program to guarantee the quality of the animals and the safety of personnel. It is important that a qualified person be responsible for health management (HM) of the facility since the decision whether a micro- organism is acceptable or not in a given animal colony is a complex issue. All the HM results of a microbiological unit (room, rack, isolator) are reported in the HM report.