Environmental Health Monitoring
Cost Analysis

There is a concern that moving from a soiled bedding sentinel program to environmental health monitoring (EHM) is going to be more costly. There are especially concerns of increased costs from PCR testing versus serology and when new equipment needs to be purchased to support EHM. However, the cost savings related to no longer using sentinel animals (purchase of animals, husbandry and maintenance and sampling), may balance the increased costs associated with EHM methods. In fact, several institutions have found that switching to EHM does not result in an overall increase in costs and may even save money as shown in formal cost analysis and reported in EHM papers (Luchins, 2020; Mailhot 2020; O’Conell 2021; Pettan-Brewer 2020).

Example Cost Analysis for Exhaust Dust Testing

University of Chicago conducted and published a detailed cost analysis when making the switch to exhaust dust testing (Luchins 2020). This institution found that EHM was 26% less expensive than SBS. Cost savings came from: 

  • Animal order 
  • Animal shipping 
  • Animal maintenance 

Below is their comparison of the total annual costs of EHM versus SBS.

  • Animal Ordering: $0 for EHM vs $415,084 for SBS
  • Animal Shipping: $0 for EHM vs $3,876 for SBS
  • Animal Maintenance: $0 for EHM vs $137,642 for SBS
  • Technician Time: $1,683 for EHM vs $7190 for SBS
  • Diagnostic Testing: $450,938 for EHM vs $449,629 for SBS
Overall the total annual cost was $452,632 for EHM versus $613,421 for SBS.

Additionally, they found that moving to EHM reduced the amount of time the veterinary technician spent on the health monitoring program. For every veterinary technician, this amounted to ~1.5 hours each week per 10,000 rodent cages. This extra time would be greatly appreciated in any animal care and use program. 

Cost savings or break-even points have also been found at University of Colorado Anschutz Medical Campus and University of Washington 

Example Cost Analysis for Sentinel-Free Soiled Bedding

Since that paper, University of Chicago has also switched their static cages over to sentinel-free soiled bedding (SFSB) sampling. Although this was a much smaller program, a cost analysis found that EHM was still 7% less expensive than SBS. 

Conducting Your Own Cost Analysis

There are a number of factors to consider in your own cost analysis. We’ve created a downloadable spreadsheet to make calculations easier for you. Click here to access. 

In any cost analysis we recommend the below factors as a starting place: 

  • Animal ordering 
  • Animal shipping 
  • Animal maintenance 
  • Technician time 
  • Diagnostic testing 

For diagnostic testing for EDT, if you have double-sided racks, you can conduct half as many diagnostic tests than with SBS. This is due to the fact that you typically have one sentinel mouse per rack side, but only one media for EDT. 

Additional costs that may be difficult to calculate can also be related to veterinary care for sentinel mice. 

We believe that switching to environmental health monitoring is worth it, since it replaces animal lives and improves scientific quality.

However, cost does matter in the real world and it's great when implementing the 3Rs can either break even or save money.