In June 2021, Evolution Rattery and Oakgrove Rattery undertook a project to try to eradicate Streptobacillus moniliformis (SBM), the bacteria that causes Rat Bite Fever (RBF), from the fancy rat breeding community, using a cross-fostering method.

Over these months, we have raised a thriving colony of pathogen free albinos, including a ‘control’ group and a foster group. We can now start offering other breeders clean rats in trios of 1 male and 2 females. We would love to be able to offer these rats free-of-charge, but the cost of maintaining our colonies without the income from adoptions has been a challenge.  We have had several generous donations; however, the majority of expenses for maintenance and testing has been out of our own pockets. Therefore, we will be charging a nominal fee of $40 per albino trio.  Likewise, when we can start offering breeding stock, we will do all that we can to charge low fees. Our belief is that we shouldn’t profit from helping the fancy rat community.

As for testing, we were excited when the community came across a low-cost testing facility, and initially used this resource for our testing needs.  Unfortunately, we received some positives which almost made us give up since the project appeared to have failed. We discussed these results with Charles River (CR), and reviewed our process and husbandry with them.  They were encouraged by our interim results and offered to sponsor several tests to confirm/deny the positives we had received from the other lab. 

We can now confirm that 100% of litters fostered so far are SBM FREE, this includes litters whose biological mothers were SBM positive!  The results we received from CR were ALL NEGATIVE! They are so extremely excited about this progress that they are sponsoring a second round of tests in a couple weeks. Since the other lab has proved to not be as reliable as we had hoped, we will now exclusively use CR for foster litter testing.

Exciting, right! That’s not all! We have also included testing for viral pathogens as part of our process.  We did this to ascertain what pathogens present in our original colony had been transferred along with the foster litter.  100% of our foster litters have tested NEGATIVE for the following pathogens:

  • Sendai (SEND)
  • Sialodacryoadenitis virus (SDAV)
  • Kilham’s rat virus (RV; KRV)
  • Lymphocytic choriomeningitis virus (LCMV)
  • Hantaan virus (HTNV)
  • Mycoplasma pulmonis (MPUL)
  • Filobacterium rodentium (CAR Bacillus; CARB)
  • Rotavirus type. B (IDIR)
  • Encephalitozoon cuniculi (ECUN) 

This means we have proved that cross fostering CAN effectively clean colonies of even some of the most difficult pathogens – especially those that can harm us. Mind you: we accomplished this without the use of antibiotics!!! We have cut no corners in this process to get as conclusive of results as possible – to the point that CR said our process was more thorough than some lab attempts at cross fostering.

We want to test at least one more generation before we claim our process to be a total success – this will be around the first of May. At that time we will publish our ‘Draft Process’ to be available to ALL. And yes!! Start adopting again!!!!!!!! Our final step has been to introduce several confirmed clean rats to our ‘dirty colony’ to gauge how susceptible they are to viral infection. This way we can inform adopters if clean rats can be safely introduced to their current mischief or if we will advise against it.

For now, please help support us if you can via our GoFundMe or if you would rather help by sending a gift card, our supplies frequently come from Chewy, Tractor Supply, and Ace Hardware. Please contact us at either or for a mailing address.