Cat Bites May Lead to Infections: Treatment and When to Get Help

Though cats are soft and cuddly, they may bite or scratch when they're spooked. When a cat bites, it may not seem like a big deal — it can be cute when they're playing — but some cat bites can pose significant health risks.

Cats carry many bacteria in their mouths capable of causing infections in bite wounds.

Though house cats are often vaccinated against the most serious diseases, like rabies, stray cats aren't usually vaccinated and can carry several diseases.

In fact, the infection rate from a cat bite is fairly high. According to a 2018 research review, infection occurs in about 50 percent of cat bites in children. Roughly 400,000 cat bites occur in the United States each year.

Cat bites with infections can become not only painful, but also red or discolored, and swollen.

If left untreated, cat bite infections can spread to other parts of the body, causing a condition called septicemia (blood poisoning), which requires hospitalization. In rare cases, these infections can be fatal.

There are tons of dangerous bacteria flourishing inside a cat's mouth. Cats' teeth are sharp and pointy. When they bite you, they are essentially injecting bacteria deep into your skin's tissue.

The puncture hole can quickly seal over and trap bacteria from the cat's mouth under your skin.

The warm and dark inner layers of your skin are optimal for the growth of the bacteria. Skin infections, known as cellulitis, can occur quickly after a bite.

Here are some of the potential infectious diseases that can happen after a cat bite:

Pasteurella multocida

Pasteurella multocida is a type of bacteria frequently found in the mouths of cats that can cause infections after a bite or scratch.

In fact, a 2013 research review showed that Pasteurella is the most common organism isolated from both cat and dog bites. Immunocompromised people are at a higher risk of developing a severe infection from these bacteria.

Cat scratch disease

Cat scratch disease (CSD) (also known as cat scratch fever) is an infection caused by the bacteria Bartonella henselae. CSD is transmitted when a cat carrying the infection:

scratches
bites
licks

The following animals are at the highest risk of carrying the infection:

kittens less than 1 year old
cats that hunt
stray cats
flea-infested cats

It's important to know that CSD is most common in children. According to Poison Control, CSD is usually not serious, but people with weakened immune systems are at risk of developing a more serious infection.

Rabies

Cats, like many other mammals, can carry rabies. This virus is almost always fatal when untreated, but it's extremely rare.

According to the Centers for Disease Control and Prevention (CDC), there are only 1 to 3 cases in the United States each year.

Most domestic cats are already vaccinated against rabies. If you know the cat that's bitten you has a rabies vaccine, it's unlikely that you'll contract rabies.

But if an unvaccinated cat has bitten you, you must take the bite seriously. Once symptoms are present, rabies is typically fatal.

You may need to begin rabies treatment if the cat that's bitten you shows any rabies symptoms. If you're bitten by a stray, it may be necessary to capture the animal so it can be observed.

Don't try to capture the cat yourself. Instead, call the animal control office in your area.

If you can't capture the cat, you might need to start rabies vaccination as a precaution.

Tetanus

Tetanus is a serious infection caused by a bacterium called Clostridium tetani. It's recommended that you have a tetanus booster after a cat bite if it's been more than 5 years since you've had the vaccine.

The most common symptoms of infection from a cat bite include:

redness or discoloration
swelling
inflammation
warmth
a bump or blister where the bite wound is located

More serious symptoms of a cat bite infection include:

pus or fluid emerging from the wound
loss of feeling near the wound
red or discolored streaks near the wound
swollen lymph nodes
fever or chills
night sweats
fatigue
muscle weakness
inability to use your hand (if your hand's been bitten)

You should also seek medical treatment as soon as possible if you start to experience these more serious symptoms.

An infection from a cat bite can lead to more serious complications if not treated right away. These include:

An infection from a cat bite may set in within a few hours, but it can take 10 days or more for some infections, like cat-scratch disease, to start showing symptoms.

The CDC says that the incubation period for rabies (time between exposure and the appearance of symptoms) can be weeks to months.

A doctor or nurse will wash the wound thoroughly, trim away any dead tissue, and apply antibiotic ointment. They may take a culture swab to help identify the type of bacteria causing the infection.

Your doctor may also recommend an X-ray to diagnose injuries to joints or bones or to see if there are any fragments from the cat's teeth that may have broken off.

Antibiotics for cat bites

A doctor will likely prescribe antibiotics to fight off the infection. Some bites require the use of antibiotics through an intravenous (IV), while others may be treated with oral medication.

Tetanus booster

A doctor may give you a tetanus vaccine booster if you haven't had a tetanus vaccine in the last 5 years.

Surgery or stitches

A doctor will decide if the wound needs stitches or surgery to heal properly.

Cat bites carry other risks besides infections. These include:

Ruptured tendon

If the cat bite is deep, it can damage your tendon(s). Tendons and ligaments in the hand are especially delicate. Tendons can rupture and may require surgery.

Nerve injury

According to a 2016 case report, cat bites can injure a nerve in rare cases. Symptoms include not only pain, but also numbness and paresthesia.

Scars

Puncture wounds tend to heal quickly, but a very deep bite can leave a scar.

Foreign objects

There's also the risk that a cat's teeth will break off during a bite and need to be extracted.

Animal bites that don't break your skin, as well as scratches that just graze the surface of your skin, have a minimal risk of infection.

You should still clean the wound area with soap and water, but it's unlikely you will have to take any action.

Puncture wounds from a cat bite have a high risk of infection. Bites on the hand are also at a high risk of infection. Wash the wound thoroughly with soap and water and cover with a sterile bandage.

If a cat hasn't been vaccinated for rabies, contact a doctor to decide if you need treatment known as rabies postexposure prophylaxis (PEP).

PEP isn't generally needed if the cat isn't showing signs of rabies, but the cat should be monitored for at least 10 days to be sure.

If a cat bite breaks your skin, you should seek medical attention if:

you start having any serious symptoms of an infection, such as fever, chills, pus or fluid oozing from the wound, or swollen lymph nodes
the wound won't stop bleeding
the wound appears to be deep or large
the cat that's bitten you appears aggressive or acts strangely
the cat that's bitten you is unvaccinated against rabies or you're unsure if the cat is vaccinated against rabies
you haven't had a tetanus shot in the last 5 years
you have a weakened immune system

A cat bite carries a high risk of infection and can be dangerous. To care for your wound at home, follow these steps:

Clean bite wounds thoroughly with soap and water.
Apply antibiotic ointment.
Cover with a sterile bandage.

If the following symptoms occur, seek medical attention:

inflammation
pain
redness or discoloration
swelling
more serious symptoms of an infection, such as fever or muscle weakness

If you have a pet cat, make sure to take them to regular veterinary visits to stay updated on vaccines.

You should also teach children how to properly handle pets and to make sure they aren't doing anything to unintentionally hurt or scare a cat.

Stay away from stray or feral cats. Wear thick protective gloves when handling an injured or stray cat.

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