American Fancy Rat & Mouse Association

This article is from the WSSF 2008 AFRMA Rat & Mouse Tales news-magazine.


Rat Virus; Soy Milk & Newborn Rats
Rat Virus

Paul & Linda Barrette, Kenosha, WI, e-mail
QThe last rats we adopted from the pet store both died about a week later. One person said one of their rats died the same way and the veterinarian said that rats from big pet stores have viruses already before you adopt them. How do rats get these viruses? Is there a cure? How many viruses can a rat get?

Answer by Carmen Jane Booth, D.V.M., Ph.D.
AUnless a necropsy was performed, you cannot know the underlying cause of death. The age of the rat is an important factor. How old were the rat or rats that died? Weanling rats are more susceptible to problems than adults. Rats can have heart defects and the simple added stress of changing location from the pet store to a new home, can cause death in some cases. Most of the rodent viruses do not cause acute death out side of neonates and are either asymptomatic, or cause respiratory or gastrointestinal problems. There are bacterial diseases that can cause acute death, but you need a necropsy and microbiology to make a diagnosis. The most common problematic agent is Mycoplasma pulmonis which is ubiquitous in pet rats from pet stores. However, this organism is associated with chronic respiratory problems in older rats, not acute death.

Viruses are transmitted through the air, direct contact, or contact with contaminated food, bedding, etc., in the same way people get viruses from each other. Some viruses the rat’s immune system will form immunity to, others they carry for life. This is the same for bacteria. Mycoplasma is difficult to impossible to eliminate once an animal is infected and is often managed with antibiotic therapy.

When addressing acute death in a pet rat, it can be useful to get information on the caging used and location in the home, in addition to food, treats, and type of water delivery (bowl, water bottle).

Answer by Karen Robbins
AAll pet rats carry viruses and bacteria, it just depends on what they carry and what kind of immunity they have for what they carry. Some viruses are deadly and quarantining/ stopping breeding for a period of time are the only things you can do to get rid of the problem. Unfortunately, commercial breeders won’t do these steps to eradicate the problem so things keep getting passed down to the babies. The babies get it from their parents and being in contact with infected rats. Pet shop breeders don’t breed for health in mind so with the stress of going to pet shops/new homes, these rats get sick very easily and usually don’t live long as you found out. Private/show breeders only breed rats that are strong/healthy and they are careful of where they get their breeding stock from. They will medicate their rats when necessary and quarantine/stop breeding if it is required. That is why we recommend people get their pets from reputable breeders—you will get healthy, friendly rats and a person to help you if needed. They will also know the backgrounds of their animals and the health history in the lines.

The places that test rats for various viruses, can test for up to 16 different problems along with Mycoplasma, which is bacterial. These tests are performed with blood samples (serology). Charles River Research Animal Diagnostic Services in Wilmington, MA,, University of Missouri Research Animal Diagnostic Laboratory (RADIL) {now IDEXX BioResearch, 3-23-16] IDEXX BioResearch, and Sound Diagnostics in Woodinville, WA are diagnostic labs that can do rodent testing. If needed, your vet could get the necessary samples to send in for testing if you have any problems with your rats in the future.

Soy Milk & Newborn Rats

Editor, Karen Robbins
QI read the following statement in a paper about hand feeding newborn/young rats and I was wondering if you knew anything about this. “Soy milk has substances that bind with calcium and can cause nutritional metabolic bone disease.” From what I could find there is nothing indicating this.

AI did some looking around the web and read some articles I found on PubMed. What you have to remember is that most of these things are based on humans who are on milk replacers for much longer than baby rats. Anything that interferes with calcium-phosphate ratio, calcium absorption, etc., can cause a problem if they are out of balance with what is needed for a long time. However, most of the problems in humans are with babies that are premature, sick, or malnourished. In humans, they recommend soy milk fortified with calcium. If you look at soy-milk-based baby formula, they have added much when compared to regular soy milk for adults. Carmen Jane Booth, D.V.M., Ph.D. *

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Updated March 23, 2016