How to Treat a Rat Bite

Rat bites are uncommon, but may cause infection

rats hanging on a rope
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Before we get into treating a rat bite, for prevention, remember that the best thing to do is to stay safe when a rat is near you. Don't approach a wild rat—generally, they are more afraid of you than you are from them—but don't count on it. If the rat is a pet and its owner is around, instruct him or her to secure the rat. Rats will bite or scratch if frightened or handled, so leave them alone.

What Can Happen If I Get Bitten by a Rat?

If you do get bitten by a rat, the main concern is developing an infection. One such infection is known as rat-bite fever (RBF), which can be transmitted either through an infected rat's bite or scratch or by simply handling a rat with the disease. It can also be contracted by eating food or drinking water contaminated by rat feces.

The two bacteria responsible for rat-bite fever are:  

  • Streptobacillus moniliformis (most common in the United States)
  • Spirillum minus (most common in Asia)

The signs and symptoms for each bacteria are slightly different. The good news is that rat-bite fever can be effectively treated with an antibiotic. If left untreated, though, rat-bite fever can be potentially fatal.

Streptobacillus RBF

Watch for the following symptoms and seek medical attention right away if you experience one or more of the following symptoms or signs:

  • Fever
  • Headache
  • Vomiting
  • Pain in the back and joints
  • Rash on the hands and feet, usually accompanied by one or more swollen joints. This rash usually appears two to four days after the fever. 

Symptoms of rat-bite fever usually appear three to ten days after the exposure or bite but may occur up to three weeks later. In most cases, the actual bite or scratch wound is healed by the time the fever starts.

Spirillum RBF

Symptoms of spirillum RBF usually come on 1-3 weeks after being exposed to an infected rodent. They are more variable than streptobacillus RBF, but may include:

  • Fever, which may reoccur after it resolves
  • Irritation and a possible ulcer at the bite wound
  • Swollen lymph nodes
  • Swelling around the wound site
  • Rash that starts after the wound begins to heal

The symptoms associated with Haverhill fever (another form of rat-bite fever that comes from ingesting contaminated food or fluids)  may develop severe vomiting and sore throat.

What Should I Do If a Rat Bites or Scratches Me?

There are several steps that you can and should take:

  • Control the bleeding and clean the wound with soap and warm water. Clean inside the wound, being sure to rinse away all the soap, or it will cause irritation later.
  • Cover the wound with a clean, dry dressing. You can put antibiotic ointment on the wound before covering. Rat bites often lead to infection. If the injury is on a finger, remove all rings from the injured finger before it swells. Watch for these signs of infection:
    • Redness
    • Swelling
    • Heat
    • Weeping pus
  • Always consult your doctor. You may need a tetanus immunization or you may need stitches
  • Wounds on the face or hands should always be evaluated by a physician because of the concern for scarring or loss of function.
  • If you are not the victim, practice universal precautions and wear personal protective equipment if available.
  • Care should always be taken to contain any rodent after a bite to determine if the animal has an infection.

Treatment from the Doctor

Rat bite fever should always be treated by the doctor in order to heal completely. If untreated, rate bite fever can be serious. The doctor will prescribe antibiotics for both types of the fever, which usually include:

  • Amoxicillin 
  • Penicillin
  • Erythromycin
  • Doxycycline 

Patients with severe forms of rat bite fever that affect the heart could get high-dose penicillin and either streptomycin or gentamicin.

A Word From Verywell

Remember, infection is the major concern with any animal bite, particularly from rats. Keep the area as clean as possible throughout healing.

Also, it is interesting to note that rats are not a major source of rabies infection – a common misconception. In fact, we get rabies from bats more often than any other animals. Raccoons are the species most likely to have rabies, followed by bats, skunks, and foxes. Rabies transmission from rodents to humans is extremely rare, so at least you don't have to worry about that!

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