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Why Do Cat Scratches Itch and Swell?

If you’ve ever had a kitten, you may have asked yourself the following question, “Why do cat scratches itch and swell?” or even “Why do cat scratches sting?” There are two possible answers to that question.

The itching and swelling that comes quickly after a scratch is part of your own body’s reaction to any damage done to your skin. But it could be a bit more…

In this article:

  • It Could Be Nothing…
  • …Or a Nasty Bacterial Infection
  • Where Does the Infection Originate?
  • My Cat Isn’t Sick!
  • How to Treat Cat Scratches or Bites
  • Final Thoughts: Why Do Cat Scratches Itch and Swell

It Could be Nothing…

Most scratches are superficial. Even if you end up with itchy skin (and a bit of frustration), there is nothing more to it.

Simply put, they are thin lines of broken skin, much like a paper cut but less regular.

It may not be significant enough to cause your body to produce endorphins to suppress the pain and thus they sting more than it seems they should for how small they are.

…Or a Nasty Bacterial Infection

However, if after a few days the symptoms persist and your itchy skin turns into something more serious, you could have caught cat scratch disease / cat scratch fever

Additional potential symptoms :

  • Localized Lesion (appears within 3 to 10 days)
  • Localized swollen lymph node (after 15 days)
  • Pus
  • Fever
  • Headache
  • Poor appetite
  • Exhaustion
  • Disseminated disease

Even though cats spend much of the day bathing, they can still be carrying around some nasty bacteria.

The Bartonella henselae bacteria in particular is the one causing that infection. This gram negative bacteria causes the cat scratch disease otherwise known as Bartonellosis.

About 40 percent of cats have it at one point or another in their lives so it is fairly common.

They can very easily share it with other cats and with their people. Kittens, who seem to do the lion’s share of scratching and biting at play, are most likely to have (and share) this infection.

If you like a more visual explanation, check out this informative video by our friends at JJ medicine.

Where Does the Infection Originate?

Cats are “reservoirs” for this bacteria but there is an additional culprit.

Fleas. Yes, here once more to ruin the day.

Fleas are the main vector of transmission for this bacteria. This means that a cat can easily transmit CSD to other cats through fleas.

The bacteria live under the cat’s claws where flea droppings collect when kitty scratches.

As she cleans her paws, she ingests it. The infectious disease travels through the bloodstream and eventually into your cat’s saliva where it comes into contact with you. However cute as it seems when kitty licks your skin, you might be asking for trouble if you allow her to continue!

Bear with us here as we get more technical. If the bacteria gets through your skin, it will invade the endothelial cells and lead to acute inflammatory reaction and lead to a pro-inflammatory cascade.

It does not sound very good but rest assured that most infections can be treated quite easily.

But My Cat Isn’t Sick! Full Diagnosis

These bacteria can be present in cats or kittens even when they appear to be otherwise healthy. You will most likely be the one to develop the symptoms.

Once you start suspecting cat scratch disease, the best way to find out is to go to your doctor and get tested.

He/she will perform a serology test or a PCR and in more serious cases a Lymph node biopsy (that last one is pretty rare).

This will tell you for sure if that’s what you got.

How to Treat Cat Scratches or Bites

Cat Scratch Treatment & First Aid

If you’ve been badly bitten or scratched by your cat, wash the wound carefully with soap and water.

Treat your injury with an over-the-counter topical antiseptic and cover it with a sterile dressing until the wound heals.

As you probably understood by now, if you develop other symptoms within two weeks of the scratch, that could mean trouble. If this happens or if you develop a fever, or see swelling in lymph nodes, seek medical help.

Cat scratch disease treatment

Often time this is a self-limiting disease which means that while closely monitored, it will be left to heal on its own.

But if the symptoms are a bit too strong, your doctor may prescribe Azythromicin for 10 days to 2 weeks. He may even combine it with Rifampin if the disease appears disseminated.

How To Prevent Cat Scratches And Cat Scratches Disease

There are several things you can do to prevent your cat from scratching you.

Adapt your behavior

If your cat likes to play it rough, you need to channel that energy into something first, before actually playing with him/her. You need to anticipate his/her moves better and deescalate the fight if it becomes too rough.

Be the smartest animal and try to keep your play session in control so you don’t get unnecessarily scratched.

Cats nails are sharp : trim them

First, we’d highly recommend getting him one scratching post in order for him/her to get his full energy on something made for this purpose. It will also naturally render his nails blunt.

Secondly, if you can, we recommend that you trim your cat’s nails often (every two weeks if you can). It takes a bit of practice but it really helps make their nails less sharp, reducing the risk of penetrating your skin too deep.

Less unsupervised outdoor time

Then, if you cannot supervise your cat when he is outside, another option would be to keep your cat indoors or prevent him/her from hanging out with potentially contaminated cats (although that may not be that easy).

Flea prevention

Finally and this may be the most important advice to protect your cat and prevent CSD, if your cat often goes outside anyways.

Make sure your cat is protected by a flea prevention medicine (weather it’s a collar of a spray, this will keep fleas at bay, reduce the risk of carrying the disease, avoid a flea allergy and prevent a flea infestation)

How to Get Rid of Cat Scratch Scars?

Even after proper treatment, you may still end up with a little scar. There is no magic formula to completely get rid of it because it depends on your skin’s ability to heal. Some people heal faster than others, nature isn’t fair!

Why do Cat Scratches Itch and Swell? | Fluffy Kitty

However, we have found that using natural vegetable oil helps in that process. We highly recommend castor oil for that matter ! This oil is amazing and helps with the production of collagen and elastin. Do check this secret remedy! 🙂

Final Thoughts: Why Do Cat Scratches Itch and Swell?

If your skin is punctured or torn by your kitty’s claws it might itch or swell.

Don’t be alarmed as it is a normal skin reaction. But, if you develop other symptoms following such an injury, you might have CSD. Seek medical help.

The best answer for your fur baby is to keep fleas away from your cat. Therefore, a really good flea protection program is essential.

Additionally, keeping your cat inside and away from other cats that might not have such caring parents is also a good plan.

Ultimately, the surest answer to cat scratch issues is to practice good first aid when kitty gets rambunctious.

Since it is kittens who are most likely to have the Bartonella henselae infection, they present the biggest risk to humans. Unfortunately, these frisky fluff-balls with their needle claws and sharp little teeth can spread the disease to their people as they play. Stay safe !

Nancye McNeill

Wednesday 29th of December 2021

I just read your article because I was wondering about why my skin was itching so bad after I was scratched and if there was a problem. We just got her a week ago and I think I am the only one that itch, so this was helpful to read and I now know what to do. Is there something I can do with her claws that would help.


Thursday 2nd of July 2020

Try not to hold a kitten for long if it's resisting harshly


Wednesday 29th of May 2019

My cat april just scratched me in one place of the scratch i got a welt its happend before but usually it gose away im really scared now she had all her shots and shes indoor cat please help me

Brittany, Paul, & Yoda =^^=

Tuesday 4th of June 2019

Hi Veronica! Usually stinging or a small infection is nothing to worry about, but anything larger than that, or something reoccurring, might mean you have a worse reaction than usual.


Friday 26th of October 2018

The bacteria comment is freaking me out. Would've never guessed that my baby was carrying that much bacteria around with her.

Brittany, Paul, & Yoda =^^=

Monday 29th of October 2018

No worries, lol! It's just like the bacteria under our nails too - except theirs stings a little when we get scratched. :)


Thursday 27th of September 2018

Thanks for this info. Your site had the best information on it. My kitten just scratched me and I was wondering if they like have poison on their nails or something cause I wondered why it itches so bad. Guess it's just a natural reaction. Lol. No poison on or in the claws. By the way I got this kitten for my birthday she's all black and named Iris. She just turned 6 months on Sept 18th.

Brittany, Paul, & Yoda =^^=

Thursday 27th of September 2018

Haha this made our day, we feel the same when we get scratches! They sometimes can itch so much, even though they're so little. That's a special day - Sept. 18th - it's Paul's birthday! Happy 6-months with your sweet Iris and thanks so much for your comment, Beth! xoxo