Rat Bite Fever: Symptoms and Treatment

Home » How to Get Rid of Rats » Rats » Rat Bite Fever: Symptoms and Treatment


For over 2,000 years, people in India have known of and feared illness caused by rat bites. It was only relatively recently that other countries, including the United States, have become widely aware of it. In the U.S., other western hemisphere countries, Europe, Australia, and, rarely, Africa, it’s called rat bite fever (RBF, sometimes RBF disease) or Haverhill fever. This version is caused by a bacterium called Streptobacillus moniliformis. In Asia and some parts of Africa, it’s called sodoku and it’s caused by a different bacterium called Spirillum minus. The first case reported in the U.S. was in 1839, but it wasn’t until 1914 that doctors figured out what caused it.

What causes rat bite fever?

Rat bite fever, specifically, is usually caused by a bite or scratch from a sick rat. If you’re wondering, “Do rats bite?”, the answer is yes. Especially if they feel threatened. Simply coming into contact with the saliva, urine, or droppings of a sick rat can also lead to RBF. Haverhill fever, on the other hand, is caused by eating or drinking something that has been contaminated with infected rat urine or droppings. Haverhill fever was named for the town of Haverhill, MA, which experienced an outbreak of the disease caused by infected milk.

Rat bite fever can also be passed through other family pets, such as cats and dogs. If a cat or dog mouths, bites or eats a sick rat, it can become infected and spread that infection to humans. The same is true if your cat or dog is bitten by a rat. People can also get rat bite fever through handling live or frozen rats that they plan to feed to a pet, such as a snake.

Rat bite fever symptoms

Rat bite fever is a very unpleasant disease. It causes fever, muscle pain, joint pain, and even death.

Symptoms of the disease caused by Streptobacillus moniliformis typically start within 3 to 10 days of exposure. If you were bitten or scratched, the injury would likely have healed before you start to show any symptoms. In addition to those mentioned above, people exhibit nausea and vomiting, headache, and rash. The rash usually shows up 2 to 4 days after the onset of fever and appears on the hands and feet. After the rash appears, joint swelling and pain often follow. In the case of Haverhill fever, a sore throat accompanies the other symptoms.

RBF infects the liver, kidneys, lungs, heart, and the brain and nervous system, causing such problems as pneumonia, excess fluid around the heart, and blood poisoning.

Sodoku symptoms typically show up between 7 and 24 days after contact with the bacterium and include fever, swelling of the bitten area, swollen lymph nodes, and rash. If untreated, RBF and sodoku lead to death in about 10% of cases.

Rat bite fever prevention

As with any illness, the best treatment is prevention.

Infants and children, the elderly, pregnant women, and anyone with a weakened immune system (e.g., people with cancer, HIV/AIDS, or transplanted organs) are at the greatest risk for infection. It’s best if people who fall into these categories neither have nor come into contact with pet rats. Over 50% of RBF cases in the U.S. are children, followed by people who work in a lab and those who work in pet shops.

Anyone who does have contact with rats, either as their job or because they have pet rats or pets that eat rats, should follow some safety precautions. If you work in a pet store a lab that keeps rats, you should always wear gloves when handling the rats under your care. In addition, wash your hands for at least 20 seconds before touching your mouth or face after handling a rat.

If you have pet rats, always wash your hands after handling or feeding your pet and after cleaning their enclosure and belongings. Don’t increase your risk of a bite by putting your pet near your face. This could scare them. Don’t eat or drink when playing with or feeding your pet and don’t bring it into the kitchen. Clean up areas where you’ve played with your pet. They can shed disease-causing bacteria from their skin. Small rodents also often defecate indiscriminately, so be especially aware of any droppings left behind after a play session. When you clean your pet’s enclosure and supplies, do so either outdoors or in a bathtub, never in the kitchen or bathroom sink. Clean and disinfect the outdoor area or bathtub immediately after cleaning your pet’s things. In addition, make sure your pet never comes into contact with wild rats. Between 10 and 100% of pet rats carry the bacteria responsible for rat bite fever. In wild rats, that number jumps to 50 to 100%.

If you have a pet that eats rats and you keep live or frozen rats as food, you should follow many of the same practices as those who have pet rats. Furthermore, don’t thaw frozen rats in the kitchen. Freezing doesn’t kill the type of bacteria responsible for rat bite fever. Never feed your pet wild rats.

Further Reading

Rat bite fever treatment

If you are bitten or scratched by a rat, immediately wash the injury. Contact your doctor and set up an appointment. Your doctor may start you on a course of antibiotics as a safety precaution.

Also, if you have any contact with rodents and begin to develop the symptoms of rat bite fever, seek medical attention at the first signs. Antibiotics are effective in treating this disease. It’s imperative that you take the full course, even when/if you feel better.

Rat bite fever and its related ailments are dangerous and can be severe or even fatal. You must take steps to protect yourself, your family, and your pets by reading the following information what kills rats instantly and using recommended rat control products.

Submit a comment

Your email address will not be published*