When To Go To The ER For A Cat Bite: A Guide to Emergency Care

When to Go to the ER for a Cat Bite - grey and white angry cat one a fuzzy white blanket

by Dr. WL Wilkins, DVM, PhD.

Cat bites are often shrugged off as minor injuries, the kind that a few antiseptic wipes and a bandage might seem to fix. After all, cats are members of our families, and their gentle nips and scratches during play are almost expected. 

However, there are moments when that unsuspecting bite should trigger an urgent response — specifically, when it’s time to go to the emergency room. But how does one know when it’s something minor vs. when to go to the ER for a cat bite?

As veterinarian, and a cat owner, I have more than a little experience with cat bites, unfortunately. In this article I will share my insight into when a cat bite is minor and when it’s an emergency. 

Join me as I walk you through the signs, symptoms, and scenarios where immediate medical attention is the best course of action.

When to Go to the ER for a Cat Bite: The Importance of Immediate Care

Cat bites have been aptly labeled as “clandestine wounds.” They might not look very serious on the surface, but their potential for danger lies in more in the bacteria carried in a cat’s mouth rather than the sharpness of the teeth. 

Cat teeth can easily penetrate deep into tissue, doing a lot of damage very quickly. Bite wounds on a finger, face, or joint can have particularly grave ramifications. As the teeth sink into the flesh, they bring along dangerous bacteria that are left behind deep within the wound. 

Because of the bacteria, even shallow wounds can be dangerous. The skin can close over the top of the wound, sealing the bacteria inside where it can  grow and cause an infection. Without proper treatment, a minor cat bite can quickly become a serious medical issue.

Identifying the Severity of a Bite

Depth, location, and bleeding should be key focal points when assessing the seriousness of a cat bite. A deep wound can travel further under the skin’s surface, complicating treatment.  The deeper the wound, the more likely that dangerous bacteria will be left behind and become an infection.

Swift action is particularly necessary if bleeding is profuse and can’t be stopped with pressure, or if the bleeding is from an area near an artery. In such cases, the ER is non-negotiable.

Bites over joints also need prompt medical treatment.  Bites near joints can cause septic arthritis, an infection in the joint. These infections can worsen quickly and lead to permanent damage if not treated promptly.

Why Bites Over or Into Joints are Particularly Bad

The joint is protected by a capsule, and if bacteria is brought into that space, it can quickly become infected.  

Joints have limited ability to fight off infection, and the joint capsule has little ability to expand to accommodate the swelling that results from the body’s response to infection. This increases pressure and decreases blood flow to the joint, leading to even further damage.

Joints also do not have much blood supply to begin with, which means that antibiotics may not be able to reach the infection as easily. This is why it is so important to get treatment early, before the infection becomes difficult to treat.  Infected joints quickly become permanently damaged joints.

When to Go to the ER for a Cat Bite - headshot of an angry orange tabby cat with mouth open snarling

It’s Not Just About Bites: Cat Scratch Disease

While less known than bite injuries, Cat Scratch Disease (CSD), also referred to as “cat scratch fever,” is another concern for pet owners. Caused by the bacterium Bartonella henselae, it is often transmitted through the scratches of an otherwise healthy-looking cat. 

This bacteria is carried by approximately 30% of domestic cats, and is more often found in kittens under one year of age. Given that kittens are more likely than their adult counterparts to bite and scratch inappropriately, even minor bites and scratches have a high chance of infection and it is always a good idea to wash scratches and bites with soap and warm water.

In healthy people, CSD usually causes mild symptoms such as fever, fatigue, swollen lymph nodes, and a small bump at the site of the scratch. However, in those with weakened immune systems or allergies to cats, the disease can become more severe, causing infections of the heart or brain if left untreated. 

Education is key; knowing how to treat cat scratches properly and monitoring for signs of infection can prevent complications.

What To Do

If you are bitten or scratched by a cat, the first thing to do is control bleeding, if necessary, by applying pressure to the wound with a clean cloth. 

Next, wash the wound thoroughly with soap and water under a faucet for several minutes. Avoid scrubbing  as this can further damage the tissue. Dry gently, apply an antibiotic ointment and a sterile bandage.

The next step depends on the severity of the wound.  If the wound is deep, if bleeding cannot be controlled, or if it is located over a joint, it’s important to seek medical attention immediately.

If the bite is minor,  monitor the area closely for signs of infection such as redness, swelling, warmth, or drainage. If you notice these symptoms developing, seek medical attention promptly to prevent further complications.

A Note About Rabies Risk

If the cat that made the bite or scratch not a family pet, e.g. it is a feral or stray cat, or even a pet cat that roams freely outdoors, you should contact your family physician regardless of the severity of the wound to report the injury. This is because of the potential risk of rabies,  which is almost always fatal if left untreated. 

The risk of rabies is why, like most veterinarians and animal health technicians, I have had a rabies vaccine. This provides me with the necessary protection should one of my patients be carrying rabies. 

Most people, however, are not vaccinated for rabies. Your doctor will assess the risk of rabies in your specific situation and if there is any risk then further steps may be needed

Making sure your cat is fully vaccinated will help reassure both you and your doctor than your cat is at not a risk of giving you rabies.

When to Go to the ER for a Cat Bite - grey kitten nibbling on a finger with white background

Recognizing the Risk of Infection

Nobody would suspect a cat of harboring dangerous pathogens, but Pasteurella multocida, present in the mouths of many cats, can swiftly turn even a superficial scratch into a nightmare. 

With up to 80% of cat bites resulting in infection, the stakes are notably high, with possible complications ranging from localized cellulitis to widespread sepsis.

Signs of an Infection

Infection isn’t straightforward, and signs can show up days after the bite. Signs to watch for include increasing or ongoing pain, swelling, redness, tenderness, warmth, red streaks around the wound, or discharge from the bite site — particularly if the discharge is foul-smelling. 

A serious infection can also cause systemic symptoms like fevers, chills, or a general feeling of being unwell.  If you experience any of these symptoms after a cat bite, get medical help as soon as possible.

If left unattended, cat bites can lead to a number of grim complications, from simple abscesses requiring drainage to deep musculoskeletal infections that might necessitate surgery.  

Tetanus Vaccines

If you experience deep puncture wounds or are uncertain about your vaccination status, you may need a tetanus shot, particularly if it has been 5 years since your last one.  While tetanus is rare, it is still a possibility, especially considering the environment where cats usually live and their tendency to nip.

Final Words, and The ER Checklist

Knowing when to seek emergency care for a cat bite is a blend of recognizing the potential threat and evaluating the specific circumstance. While not every nip warrants a trip to the ER, there are red flags that demand immediate attention. Here’s a checklist:

  • Heavy bleeding that won’t stop.
  • If the bite is near a joint or affects mobility.
  • Deep punctures and head, face, or hand bites.
  • Any instance where the victim is immunocompromised or has not had a tetanus booster in the last 5 years.
  • If in doubt, go to the ER. It’s always better to err on the side of caution and get medical advice than to risk complications by waiting.

The Forgotten Factor: Prevention

The ultimate goal, of course, is to avoid cat bites altogether. For pet owners, ensuring a well-socialized cat through early socialization and handling can preempt aggressive behaviors. 

This means understanding a cat’s body language and not engaging in play that’s too rough. Knowing the limits and moods of your feline housemate can save you an emergency room visit.

For non-pet owners, respecting a cat’s space and not attempting to handle or pet a cat in distress are key. Approaching unfamiliar cats gently and with caution is a more casual safety measure.

In all these scenarios, preparation, knowledge, and vigilance are our best defenses. Cats may have nine lives, but humans have only one — and it’s wise to protect it when a feline’s involved. 

Remember, your health, safety, and peace of mind are worth far more than the initial pain or inconvenience of a trip to the emergency room.

[Editor’s Note: Cats that get bitten by other cats need medical care too, for all the same reason described above. Learn how to recognize signs that your cat needs veterinary care in our article How To Tell If Your Cat Is Sick]

When to Go to the ER for a Cat Bite - brown tabby cat biting a hot dog, teal blue background

Disclaimer: This article is intended for informational purposes only, and does not constitute medical advice. Always consult your veterinarian or your doctor if you have specific concerns about your pet’s health – or your own.


Bone and Joint Infections: https://www.mayoclinic.org/diseases-conditions/bone-and-joint-infections/symptoms-causes/syc-20350755

Cat Scratch Fever: https://www.cdc.gov/healthypets/diseases/cat-scratch.html

Cat Bite Cellulitis: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4131574/

Treatment of Cat Bites or Scratches: https://www.stanfordchildrens.org/en/topic/default?id=treatment-for-dog-and-cat-bites-and-scratches-90-P01897


  • Dr. Wendy Wilkins DVM PhD.

    Dr. Wendy Wilkins is an experienced veterinarian and epidemiologist with over 20 years of expertise. She holds a Doctor of Veterinary Medicine (DVM) degree and a Doctorate in Epidemiology from the University of Saskatchewan. Throughout her career, Dr. Wilkins has excelled in clinical practice, academia, research, and regulatory veterinary medicine. She is a respected voice in knowledge dissemination, delivering factual information in a readable and understandable manner through articles, books, and public engagements.