American Fancy Rat & Mouse Association

This article is from the WSSF 2013 AFRMA Rat & Mouse Tales news-magazine.


Daughter With Rat Bite Fever

By Carmen Jane Booth, D.V.M., Ph.D.

Karen K. Martien, Ph.D. Southwest Fisheries Science Center, La Jolla, CA, e-mail
QDear Dr. Booth, I saw a message you posted to the AFRMA Medical site regarding rat bite fever. My 7-year-old daughter was just diagnosed with RBF. She got it from our pet rats, which we adopted 2.5 weeks before she got sick. Fortunately, she was diagnosed early and is recovering. Now we are trying to figure out whether or not we have to have our pet rats put to sleep. I can imagine explanations for why my daughter caught RBF, even though it is so rare even among rat owners. Explanation #1 is that one of our rats carries a particularly high concentration of Streptobacillus moniliformis and is therefore much more likely to transmit the bacteria than most pet rats. If that is the case, we should have the rats put to sleep so as not to catch it again. Explanation #2 is that our rats are just like any other pet rats and the fact that my daughter caught RBF was just a supremely unlucky fluke. Do you have any information or data that would help to distinguish these possibilities? Do you know if rats vary in terms of their degree of colonization by S. moniliformis? Any advice or insight you can offer would be greatly appreciated.

AAll animals carry bacteria that can potentially cause disease in people. Rats are no exception. RBF is a general name for some bacteria that can cause disease in people. The research paper “Rat Bite Fever” you might find interesting. I am not a microbiologist and if you do a literature search you will find that RBF happens fairly uncommonly when you consider the number of people with pet rodents and/or other animals that can carry these bacteria in the general population. This is good news. Unfortunately, pet store rodents are far more of an issue than rats from good AFRMA breeders, of which there are many in Southern CA. However, outside of research animals that are specific pathogen free, there are no SPF animals (rodents, dogs, cats, rabbits, Guinea pigs, etc.) in the pet world. So, any and all animals carry some risk of bacterial zoonosis. As a veterinarian I have had to go on antibiotics, once for a dog bite and twice for cat bites and one was from my own cat and she lived to 17. None were euthanized and none were treated with antibiotics. In reality, bites from people can be just as bad for causing bacterial infections. If you read the literature on zoonosis, it is a wonder anyone would have any pets at all. One has to make their own risk-benefit analysis for having pets. For some therapy dog clients, I have to do specific bacterial cultures on their dogs to make sure they don’t have MERSA (Staph. aureus) as a requirement for some places they go to. I can’t find any specific publications online on treating rats to eliminate or prevent RBF. My books are at work. Myself, I had pet store rats middle school through early college, then switched to AFRMA rats, and ultimately research rats since my work and graduate school prohibited contact with non-SPF rats. My own kids have had rats from work. Individual animals could be cultured (oral, fecal) to see if they carry specific types of bacteria and a culture and sensitivity can be done to determine what specific antibiotics are needed to treat them. In general, Strep. spp. are sensitive to routine antibiotics. As a small animal veterinarian, other than in the case of dogs with dangerous aggressive behavior or where there is the risk of Rabies or in rodents with LCMV, euthanasia has not been my recommendation. In research, we function on a herd health basis for the rodents, and many, many thousands of dollars are spent checking and screening the colony for pathogenic and opportunistic bacteria, rodent viruses, and rodent parasites. Infected colonies are treated depending upon the agent found, and in some cases specific colonies are culled. I wish you the best with your daughter and your ratties. Carmen Jane Booth, D.V.M. Ph.D.

Update: Thank you so much for your response. It is exactly the type of information I need in order to make a rational decision. I’ll continue to look for information regarding the possibility of treating our rats with antibiotics. I hope that AFRMA does post this exchange to their web site, as I’m sure others will find it helpful as well. The only thing I would add is that my daughter was never bitten by our rats. She had to have contracted RBF through close contact (i.e., cuddling and kissing). *

Other articles on Rat Bite Fever:

And for more on zoonotic diseases see:

There is an article “Reducing the risk of human infection from pet rodents” written for those in the U.K. In this article it lists Leptospirosis sp., Hantavirus, Rat Bite Fever from Streptobacillus moniliformis, and LCMV (Lymphocytic choriomeningitis virus) as being the most common diseases people can get from pet rats. Good hygiene is important when handling animals of any kind. And don’t let pet rats (or mice) be exposed to wild rats (or mice) at any time.

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February 7, 2015