Personal tools
Document Actions

Rodent Health Surveillance & Disease Prevention

The Animal Resource Program surveillance system is used to monitor the health of Penn State rodent colonies.

Colonies of research rodents are susceptible to infection with a variety of bacterial, viral and parasitic agents. In many instances these agents produce no clinical signs yet result in physiologic changes that may alter, and in some cases, invalidate research carried out on infected animals. In addition, a few agents may infect people working with animals. Therefore, it is important to maintain rodent research colonies free of infectious agents.

Disease Transmission

Infectious agents may enter an animal colony via several routes including:

  • Infected animals imported from outside the university
  • Contaminated cell lines which are subsequently introduced into rodents
  • Contaminated personnel or equipment entering the facility
  • Feral rodents within the facility

Once introduced into a rodent colony, an infectious agent may spread (be transmitted) rapidly through the animal facility. The ease and potential impact of such transmission has fueled the development of complicated housing systems such as barriers, microisolation systems, and positive pressure ventilated caging. Routes of transmission include:

  • Direct contact between animals
  • Dissemination through the room air
  • Transportation of agents on equipment, instruments, and personnel

In order to minimize the chance of introducing infectious agents to our colonies, the university purchases animals only from reputable vendors who perform and report the results of extensive rodent health monitoring. Only animals that meet pre-established standards are accepted from these approved animal sources.

All animals entering from non-approved animal sources are quarantined on arrival and tested before release to Penn State colonies.

In addition, all cell lines obtained from outside the university are tested for murine pathogens before they are used in rodents.

Health Surveillance Procedures

The Animal Resource Program has developed a surveillance system to monitor the health of each Penn State rodent colony. The effectiveness of this system depends on obtaining the most representative animals from each colony as sentinels for periodic testing. At Penn State, sentinel animals are housed on soiled bedding collected from the cages of research animals. These sentinel animals are therefore exposed to all the other animals they represent via this dirty bedding. For more information on how sentinel animal cages are handled see the ARP training videos on sentinel cage changing procedures.

Sentinel animal cages are distributed at the ratio of 1 cage for each 50-75 cages of colony animals. The lower right position on each rack is designated for a sentinel cage for that rack. The sentinel cage is marked by a yellow cage card. Please do not move or disturb the animals in these sentinel cages.

There are agents of concern that are not easily transmitted to sentinel animals by soiled bedding. One method sometimes used to increase the sensitivity of our system is to obtain culled animals from each colony being monitored that will become the sentinels housed on soiled bedding. 

Quarantine for Imported Animals

All laboratory animals arriving on the Penn State University Park campus from non-approved animal sources (see below for definitions) must undergo a period of quarantine in a protected area of the animal facility. This period allows the animal(s) to recover from the stress of shipment and to be screened for clinical health problems and infection with pathogenic organisms to prevent introduction of disease to the animal facility. The quarantine period will be dependent on the animal species, source and health status.

Approved Animal Sources

The following commercial vendors are approved animal sources:

  • Charles River
  • Envigo
  • Taconic
  • Jackson Laboratories

Non-approved Animal Sources

These include all commercial vendors not listed above and laboratory animal facilities associated with other colleges or universities and private companies. Please see the Importation of Animals to Penn State from Other Institutions section of this website for further information.