Even as medical technology strives to keep up, the rise of new pathogens, such as severe acute respiratory syndrome (SARS), and the emergence of tougher versions of old foes, such as drug-resistant tuberculosis, remind us that pathogens will seldom miss an opportunity to spread. Factors such as increasing international travel, rising population densities and variations in regional sanitary standards are often cited as threats to public health; however, it should also be recognized that the same factors pose just as great a threat to even the most seemingly secure laboratory rodent populations.

Before the advent of modern genetic engineering techniques, most laboratory rodents were obtained from commercial breeders that would generally be considered “clean”; it is now common for different institutions—each with their own level of cleanliness—to exchange unique strains. Furthermore, the number of mice used in research has skyrocketed in recent years, resulting in many institutions housing more and more mice within a limited space, unless they have the luxury of being able to build a new facility. Finally, genetic engineering techniques are being used to create an ever-increasing number of transgenic and knockout mice, many of which are immunocompromised and, therefore, especially susceptible to infection. These factors all add to the risk of a disease agent being introduced into and spreading within a laboratory rodent population.

In this issue, we continue the theme of “protecting your research investment” from last month with a group of articles addressing strategies to protect laboratory rodent colonies from contamination and outbreak of disease. Now more than ever, animal facilities need to have programs in place to prevent the introduction of disease-causing microbes and, should pathogens sneak in, stop their spread before they decimate the colony or irreversibly damage research projects.

The importance of rodent health monitoring programs cannot be overestimated. Since many of the microbes that infect laboratory rodents do not cause overt clinical symptoms, physical observation of the animals is often not enough. Sentinel programs are a valuable tool for the detection and interception of contagion, but their implementation is perhaps not as straightforward as one might think. How many animals to use, what strain, whether males or females are more appropriate, how they should be housed, how often and by what method should they be tested are among the many questions that must be answered. Authors Livingston and Riley (p. 44) and Lipman and Homberger (p. 36) attempt to provide practical answers for these and other questions.

Facility water and sanitation monitoring programs also play a vital role in maintaining rodent colony health. Authors Edstrom and Curran (p. 32) discuss the factors to consider when developing a water quality assurance plan, including an overview of purification and water treatment processes and watering system architecture.

Chemical decontaminants used in conjunction with a program to monitor surface decontamination can be very effective at preventing the spread of disease. Parker et al. (p. 26) discuss the proper use of disinfectants, sanitizers, and sterilants, and outline various types of tests, such as those that detect the presence of residual protein or ATP, to detect the presence of potential disease-causing organisms on surfaces within the animal facility.