Dear Dr. Kaplan: Herbie is a domestic white rat that I bought for my son eight months ago. My son is seven years old and is allergic to dogs, but was happy to settle for a rat. Herbie is now almost a year old and has been quite a good pet. My son has taught him a couple of tricks and spends one-on-one time with him daily.
Last week, my son offered Herbie a treat. When initially taking the treat from my son's hand, Herbie seemed to miscalculate and produced a mild bite on my son's finger. Herbie released his bite as soon as he realized he was biting my son's finger instead of the treat. The resulting wound was washed with soap and water and quickly forgotten.
Three days later, my son developed a headache, fever, muscle aches and chills. I thought he had the flu and took him to his doctor. The doctor suspected rat bite fever and placed him on antibiotics. My son quickly recovered. Rat bite fever was later confirmed by a lab test.
What is the cause of rate bite fever and should I get rid of Herbie? If I remove Herbie from the household, my son will be heartbroken.
ANSWER: Rat bite fever is an uncommon disease that can be life-threatening. It is caused by bacteria that most rats carry known as Streptobacillus moniliformis. It is usually spread by bite wounds, but can also be spread through contact with rat saliva on open skin sores or other close contact like kissing or sharing food. Prompt treatment with appropriate antibiotics is usually curative as long as the infection has not spread to the heart (endocarditis). Onset of symptoms usually occurs two to three days after exposure, but incubation periods longer than three weeks have occurred.
Whether or not you keep Herbie is up to you. However, owning any pet carries some risk. Since the bite appears accidental, I believe the risk of a recurrence of rat bite fever is small. Certainly, ask your son's doctor as well for his or her opinion.
If you do keep Herbie, make sure your son is handling Herbie properly. Inspect the cage housing Herbie and make sure there are no sharp edges that may lead to inoculating someone with Streptobacillus moniliformis. If anyone in the household has sores on their hands, they should avoid contact with Herbie or at least wear gloves when handling him. Hands should always be thoroughly washed with soap and water after handling Herbie. Finally, do not allow anyone to kiss or share food with Herbie.
Personally, I believe rats can make excellent pets. My youngest son's first pet was a "rescue rat" that taught him much about responsibility and empathy for others.
Eliot Kaplan is an Okanagan resident and holds a diploma from the American Board of Veterinary Practitioners. Questions can be directed to