Rodent Health Surveillance Program

All rodents housed in the CCM (formerly CLAC) animal facility are tested periodically by Rodent Health Surveillance Program. This is to ensure the specific pathogen free status of the animal housed in our colony and to detect any unwanted or adventitious pathogens entering in to the facility. Any presence of unwanted pathogens have a deleterious effect on the well being of the animal and have more devastative effects on the research data.

The rodent health surveillance program is done by exposing sentinel animals to dirty bedding. A sentinel cage with two sentinel animals (female outbred) are placed on each side of the rack (one sentinel cage for 70 cages) and are exposed to dirty bedding from the other cages during routine cage change. These sentinel animals after six to eight weeks of exposure are then submitted for completed health assessment. It includes gross necropsy, parasitological and serological examination for any pathogens.

Our Animal Care and Use Committee (ACC) require that tumors, tissues and biologicals inoculated into live rodents be shown to be pathogen-free using PCR technology.

Purpose/Scope

The purpose of this policy is to ensure all research animals housed at The Center for Comparative Medicine (CCM) and at Gene Targeting and Transgenic Facility (GTTF) have a standard Rodent Health Surveillance Program to detect unwanted pathogens.

This Standard Operating Procedure (SOP) outlines the animal husbandry practices associated with the Rodent Health Surveillance Program at the CCM.

The health status of all rodents (mice and rats) housed at the CCM are monitored by the Rodent Sentinel Health Monitoring Program using their dirty bedding.

Policy

It is the CCM policy to meet or exceed all federal, state, and local regulations and guidelines and to comply with all institutional policies and procedures as they apply to the use of animals in research.

Personnel must attend any applicable training in animal care and use, occupational health and safety, equipment operation, and Standard Operating Procedures prior to performing activities outlined in this SOP.

In addition everyone entering an animal room is expected to comply with current traffic pattern rules, dress code, and use of PPE as specified on the Room Quality Control Report. In addition, protocol specific SOPs may apply depending upon agents used.

Target Users

• Animal Care technicians and Supervisor
  • Veterinary Technician
  • Attending Veterinarian

Procedures

Procurement

Source: Charles River Laboratories

Mice: 3 to 4 week old CD-1 females
Rats: 4 week old Sprague-Dawley females

Place order for the sentinel animal at least two weeks prior to placing them in their sentinel cages

Allotment of Sentinel Animals

Veterinary Technicians will contact the Animal Purchase Officer regarding the number of sentinel mice to be ordered. This is done to ensure every rack in each animal holding room contains two outbred female sentinel animals (CD-1, Charles River Laboratories).
Upon arrival, mice will be ear-notched and assigned to the existing sentinel cage in each rack.

Always house the sentinel cage at the bottom shelf of the racks on each side of the rack. (one sentinel for each 70 cages)
Fill out the sentinel cage cards (place a transparent red) indicating holding room number, floor and rack that the sentinel cage is placed on.

Sentinel animals should be undergo dirty bedding study for at least eight to ten weeks before being submitted for necropsy/serology.

Animal care staff and Animal Care Supervisor should notify the Veterinary Technicians when a rack is without sentinels or when sentinel animal is dead to prompt quick addition of lost sentinel animals in the racks.

Soil-bedding Transfer

Change sentinel cages at the same time as the other cages in the room.

•  Always change the sentinel cage last.
  • In case of ventilated racks, a scoop of bedding from all cages of the rack is collected in a clean empty cage kept in the cage changing hood. This pool of bedding is thoroughly mixed, and one scoop of soiled bedding will be transferred to the clean cage for the sentinel animals.
• Approximately 50 percent of bedding in a newly changed sentinel cage should be soiled bedding from the mouse colony.
• Always use a separate cup for each side of the rack to avoid cross-contamination.
  • Transfer the sentinel animals to the sentinel cage.
  • Date and initial the back of each sentinel cage card (one cage card per sentinel animal) after each cage change.

Frequency of Testing/Submission and Evaluation of Sentinel Animals for Parasitological Examination

Note: The sentinel animals are collected QUARTERLY, and appropriate testing is done. Only one animal from each cage (necropsy and serum sampling) is submitted to the diagnostic laboratory for evaluation. Each cage/cup is labeled with the tower number, room number, rack number, and date of arrival.

• Each sentinel is evaluated for ectoparasties by anal cellophane tape test of perineum; and examined under microscope for pinworm ova.
• Each sentinel animal is evaluated for fur-mites by fur pluck testing.
• Each sentinel is evaluated for endoparasites by fecal floatation. At least one fecal pellet from each sentinel cage in the room is pooled.
• Yearly once (Q1), helicobacter testing was done on fecal samples. One fecal pellet from each sentinel cage in the room is collected and pooled for fecal Helicobacter PCR testing. The testing is done by the Gene Targeting and Transgenic Facility.
• Each sentinel is bled and evaluated for comprehensive or basic serologic profile (see below). Blood samples are collected by one of the standards methods for that species with appropriate methodology. The blood will be spun and serum will be separated and stored in a negative 70 degree (Celsius) freezer for evaluation.

Basic Serology Profile (CRL, Tracking Profile)

Comprehensive Serology Profile (CRL, Assessment Profile)

Bacteriology profile is not performed.