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Our Rats Have Tested Negative for Rat Bite Fever and the 3 Main Zoonotic Viruses!


Zoonotic Diseases

Like all animals, rats are capable of carrying infectious agents that can be harmful to people, other pets, or existing rat colonies. Though the risk is low, it is still important to have a proper understanding of the most common agents, the symptoms they may cause, and the methods to best protect yourself from them.  

Our Policy

Here at Mini Mischief Rattery, we make it our goal to breed rats that are clear of zoonotic (capable for spreading to humans) agents. We recently completed health testing to ensure that our colony is clear of the most problematic diseases. The two main areas of testing are serology testing for viruses and PCR testing for the bacterium Strepptococcus moniliformes (responsible for Rat Bite Fever). Read below to see what we're doing to test for and combat each of these!


Serology testing


We have completed serology blood testing through Charles River Labs and tested negative for the 3 main zoonotic viruses - Seoul Virus, LCMV, and Sendai virus - as well as SDAV, a virus that can be dangerous to other rats. Viruses our colony tested positive for are mycoplasma pulmonis (MPUL), Car Bacillus (CARB), and Rat Parvovirus (KRV), all of which are common, rodent specific, and of no risk to people, immunocompetent rats, or other pets. We have provided more information on the listed viruses below.

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Rat Bite Fever (RBF)

Rat Bite Fever is caused by the bacterium Streptococcus moniliformis (SBM). This bacterium is carried by rodents and can be spread to humans through a bite, scratch, or contact with urine and droppings. It is not a new bacteria and is not considered a reportable disease by the CDC. In most cases, this bacterium causes no symptoms or mild symptoms. However, in rare cases, particularly for the very young, very old, or immunocompromised, it can cause severe illness and even death if untreated. If recognized, it can be treated easily with antibiotics. Therefore, it is important to recognize the symptoms if you have pet rodents. 

Symptoms Include:

Rat Bite Fever is still not well understood by the scientific community. Prior to 2020, it was believed to be a normal part of all rat's gut flora. Now it is still considered to be "normal" in the sense that it is common and asymptomatic to rats, but not all rats test positive on PCR lab tests. To make matters confusing, there are cases where rats that test negative later become positive without any cross-contamination, as well as cases where rats can test negative after living with positive rats. Some theories as to why this may be include that the bacteria levels might naturally fluctuate throughout a rat's life or that PCR tests aren't always capable of detecting it. It is common in the environment anywhere that wild rodents live. Estimates state that anywhere from 10-100% of the domestic rodent population carry this bacteria (which isn't much help at all!)

PCR Testing

Due to the still-emerging science, many breeders choose not to test for this bacteria and instead simply educate adopters about the risks. This has been the primary policy in the rat breeding community until quite recently. Now, with new testing methods available, many breeders are choosing to test their colonies in attempt to remove the bacteria from the pet population. These methods aren't yet 100% accurate, but they're a great start towards the goal of producing healthier safer pets! Here at Mini Mischief Rattery, we are proud and excited to announce that our colony has tested negative for Rat Bite Fever!


Testing for SBM can be done through PCR lab tests. We recently completed the process of individually swabbing our entire breeding colony to determine if any of our rats tested positive for SBM. We tested through Research Associates Laboratory and were very excited when results came back negative on all 24 tests! We can now guarantee that we are breeding only rats that read negative on PCR test!


However, due to the confusing nature of this bacteria and its prevalence in the environment, we cannot make guarantees that all babies will remain free of RBF-causing bacteria once in their new homes.  Therefore, we still highly encourage all adopters to educate themselves on rat bite fever symptoms and follow proper hygiene habits around their pets (maintaining a clean cage and washing hands after handling). 

  • Fever

  • Vomiting

  • Headache

  • Muscle pain

  • Joint pain or swelling (about 5 in 10 people with RBF have this)

  • Rash (occurs in about 3 out of 4 people with RBF)

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