Cat Bites: When They Turn Into an Abscess

Have you ever heard the phrase “once bitten twice shy”?

While that phrase may apply to some cats when it comes to avoiding repeated bites or scratches from fighting, more often than not, many end up being repeat victims.

A big negative side effect of bites and scratches, besides their pain and discomfort, is the development of an abscess.

Having an understanding of cat bite abscesses, why they form, what symptoms they cause, and how they are treated, will help you help your feline friend.

Why Do Cat Bites and Scratches Cause Abscesses?

While there are many potential causes of abscesses in cats, a bite from another animal is the most common cause.

Think of a cat’s tooth or nail like a little contaminated hypodermic needle. When a cat bites or claws another cat (or you), their teeth or nails easily poke deeply through the skin, and the bacterium on their tooth or claw is left behind. When the small puncture wound rapidly closes, it seals the bacteria beneath the skin.

Under the skin, the trapped bacteria multiplies. The resultant infection triggers an inflammatory response causing large amounts of white blood cells to be drawn to the area. Pus develops and the infection turns into an abscess. This could take as little as 2 days.

Bacteria that are pus-forming include the following:

• Staphylococcus
• Escherichia coli (E. coli)
• Pseudomonas
• Mycoplasma
• Pasteurella
  • Note: About 70 to 90% of cat’s mouths contain this bacterium and it is one of the most common bacteria found following a bite in both cats and humans (found in about 50 to 80% of bites)
• Corynebacterium
• Actinomyces
• Nocardia
• Bartonella
  • Note: Bartonella henselae, the causative agent of cat scratch fever, infects about 40% of cats and most do not show signs of illness.
• Some Streptococcus species
• Bacteria that live and grow in the absence of oxygen

It usually takes two to seven days for an abscess to develop after a cat is bitten.

Symptoms of a Cat Bite Infection

You may not even know your cat has been bitten or clawed until the area swells because upon exiting the skin, the tooth or claw may leave no visible mark, and often bleeding doesn’t occur. Therefore, it is important to recognize the symptoms your cat may exhibit if they are developing an abscess.

Abscesses can form anywhere on the body but knowing where the most common locations for an abscess to form is helpful when monitoring your cat, especially if you know they got into a fight. Common locations include:

• Head
• Neck
• Back
• Base of tail
• Limbs
  
  

Symptoms of a cat bite abscess include:

• Signs of pain, such as pawing or licking the area
• Fever
• Skin may be red, swollen, or inflamed
• Soft swollen wound under the skin
• Loss of hair at the location of the abscess
• Blood or pus in the hair or skin
• Excessive itching
• Decreased appetite
• Lowered energy levels
  
  

Cat bites can be very serious even when they don't leave visible wounds or draw blood.

Cats hunt and eat meat, so their sharp teeth are designed for puncturing through skin to facilitate this. Those sharp canines are covered in bacteria which is deposited into another animal or the person they bite.

How Cat Bite Abscesses Are Treated

Untreated fight wounds can easily become infected. A cat’s mouth carries as many bacteria as a dog’s, but their teeth are better suited to transmit those bacteria, even through minute puncture wounds, according to researchers with the Mayo Clinic.

While some cat bite abscesses may rupture releasing a thick, yellow, and often foul-smelling discharge, and then heal on their own with some home care, these injuries are best dealt with by a veterinarian. Even if they rupture and appear to drain fully, some cats can still experience symptoms and if left untreated, it can lead to a potentially fatal condition, such as sepsis. 

The good news is that treatment of most cat bite abscesses does not require hospitalization.

Cleaning the Wound

The main goal is to remove the pocket of pus. This is commonly done by lancing the abscess and flushing it. In some cases, surgical debridement (removal) of some tissue may be necessary if it is necrotic (dying) or significantly damaged.

Often a surgical drain is placed in the skin pocket to assist in cleaning and further drainage of the wound. Your veterinarian will instruct you on how to keep the drainage site clean.

Cleaning is usually recommended twice daily until the drain is removed by your vet. Clean the area as directed and only use products your veterinarian has recommended. The drain is typically removed 3 to 5 days after placement but in some cases, it may need to stay in place longer.

If a drain is placed and/or surgical debridement is necessary, your veterinarian may send your cat home with an Elizabethan collar so that they can’t pull out the drain prematurely or traumatize the surgical site. It is not advisable to use a surgical cat suit because the area of the abscess has to drain and the suit could result in too much moisture on the area.

Also, removing the suit to clean it may snag the drain and pull it out, cats can chew through a suit and remove it, and the suit can rub the drain causing further trauma. Drains are only held in by one single suture typically, so it doesn’t take much to remove it. 

Antibiotic Treatment

An essential component of successful cat bite treatment is appropriate antibiotic therapy. Your veterinarian will select an antibiotic based on the most likely bacteria present in the abscess.

So that they can select the most effective antibiotic, they may recommend that the pus from the abscess be cultured so that the bacteria present can be identified. The type of bacteria and the location of the abscess will determine how long your cat receives antibiotic therapy.

NOTE: It is critical that your cat receives the antibiotic as directed (once, twice, or three times daily) for the entire length of time it is prescribed, even if they seem better.

Your veterinarian may also prescribe pain medications in addition to antibiotics.

Restrict Movement

During the healing process, especially if your cat has a drain or sutures, you must restrict their activity. Depending on the size and if surgery was performed, this may last up to 14 days.

These articles, Where to Put Your Cat After Surgery and How to Care for Them and What to Expect After Your Cat's Surgery provide some helpful information about this process.

It is important to follow ALL of your veterinarian’s discharge instructions as well as keep all your cat’s veterinary recheck appointments so that if there are any complications, a new treatment plan can be started promptly.

Other Common Cat Fight Injuries

In addition to bite abscesses, bite wounds are also the primary way of transmitting Feline Immunodeficiency Virus (FIV – a.k.a. “feline AIDS”), as well as Feline Leukemia (FeLV). Read more about FIV and FeLV.

Cat claws also carry a ton of their own bacteria, which will fester and thrive in the warm moist environment of a fresh wound. In fact, cat scratch fever (the horribly painful disease for humans, not the horribly painful song by Ted Nugent) is caused by the Bartonella bacteria transferred through a cat’s claws, which is actually transmitted to a cat through fleas.

NOTE: Symptoms of cat scratch fever in people, which occur three to ten days following a cat scratch include swollen and painful lymph nodes (usually near the scratch), bumps under the skin, rash, fever, achy muscles, bones, or joints, loss of appetite, weight loss and fatigue. Read more if your cat has scratched you.

Eye injuries, such as eyelid lacerations, corneal injuries, or even a punctured eye, can result during a fight as cats claw at each other.

While it may come as a surprise, cat fights that are aggressive or occur among larger cats, can result in broken bones.

How to Help Prevent Cat Bites

Unfortunately, bites and scratches are sometimes the end result of catfights. Your cat doesn’t have an armory of self-defense weapons to choose from. They use teeth and claws for protection.

Cat fights are usually based on a single trigger — fear. It can be fear of physical harm, resources being stolen, potential mating partners being stolen, being driven out of their preferred territory, etc.

It goes back to instinct. Self-preservation is their top priority.

Outdoor Cat Fights

Cat fights are probably more common outdoors. As cats prowl neighborhoods and city streets, they may fight when there is competition for resources (like food and fresh water) or a mate. These encounters become more likely as cat territories are shrinking and neighborhoods become denser.

According to Marci Koski, a certified feline behavior and training professional, studies have shown that cats' home ranges and territories are shrinking as the environment gets more crowded with cats — in other words, more cats in closer proximity equals more encounters and more fights as they compete over resources. And these chance encounters are more likely during the pre-dawn and post-twilight hours when cats are venturing out to hunt (cats are crepuscular — most active at dusk and dawn).

Unneutered males are often more prone to fighting as they look for females to mate with. They want to keep other tomcats from encroaching on their potential mates, as well as the other resources they need to survive.

Male cats can also do some damage to females during mating, as they bite their necks.

To lessen cat bite abscesses for your outdoor cat, consider one (or more) of these prevention options:

• Neuter or spay your cat

Note: Unneutered males are far more likely to fight than neutered cats. This is even true of multi-cat households, where unneutered males are more likely to fight with each other as well as spray to mark their territory. Neutering indoor-only cats won’t eliminate fighting, but it should reduce the number of fights.

• Keep outdoor cats indoors as much as possible, especially during pre-dawn or twilight hours.

  • Pro Tip: Consider using calming pheromone plug-ins and calming treats as well as mental enrichment to help make your cat's indoor time less stressful.

• If you are unable to keep or bring your cat indoors, provide them with a safe outdoor cat enclosure. There are many to choose from or you can build your own.

• Around your home, if possible, provide hiding places and climbing spots to help your cat escape confrontations.

• If you are there when a fight breaks out, try to distract the cats by making a loud noise (i.e., clapping your hands).

  • Note: NEVER put yourself at risk by physically intervening in a catfight. The infection rate for cat bites in people is 30–50%.

NEVER EVER allow a declawed cat outdoors. Without their claws to grip or defend themselves, they are at a higher risk for injury.

Indoor Cat Fights

Unfortunately, the same fear triggers exist for inside cats too. It can be two cats who weren’t properly introduced and still see each other as a threat — whether that’s a physical threat or competition for resources. After all, your cat doesn’t know there’s an endless supply of food and fresh water.

It also happens when two cats who get along well are startled by something, like a dish being dropped and shattering. That fight-or-flight instinct kicks in. Even though neither cat did anything, one or both may come out swinging because they feel they’re in danger. This is called redirected aggression and can result in a bite injury.

Redirected aggression can also happen if your cat sees a stranger cat through the window and gets really worked up and fearful. They may redirect on another pet or person who’s inside the home with them.

It’s not a reflection of their personality. It doesn’t mean they’re “dangerous.” Any cat is capable of redirected aggression because we didn’t breed that instinctual reaction out. It’s a cat thing.

If your cats are fighting, you can help improve the situation. If they can still share space calmly at times, try the tips in this article. If they can’t be in the same space at all without fighting, your best bet is to reintroduce them as if they’ve never met. Don’t worry. We’ve got an article on that too.

May you and your cat(s) stay safe!