Cat scratches with serious consequences: When should you worry?

What's the problem?

Pets are always close by. They give us warmth and unconditional love, and, in difficult times, help us relieve stress. For many, pets are family members, part of everyday rituals and joy. 

With this love also comes responsibility, including for your health. Even the sweetest, fluffiest pet can carry infections you need to know about. One is cat scratch disease, a bacterial infection you can catch after a simple scratch, or even when your cat rubs up against you and licks your hands or face. In some cases, the disease can cause serious complications, especially in people with weakened immune systems.

What's the solution?

In this Rubryka piece, we'll explain everything you need to know about cat scratch disease and other zoonotic infections — diseases that stray and domestic cats can pass on to people. What symptoms should you never ignore? When should you see a doctor? And how can you safely cuddle your cat without unnecessary risk?

We'll share insights from experts, including epidemiologist and infectious disease doctor Yulia Boiko and infectious disease doctor and physician Olha Laziuk.

How does it work?

Cat scratch disease, or feline bartonellosis, is an infection caused by the bacterium Bartonella henselae. It's common anywhere domestic or stray cats live, since they can spread it to each other and then to people through direct contact.

Global statistics on this illness aren't fully known, but WHO experts believe the numbers are significant.

Cats with fleas are 29 times more likely to transmit the infection. Stock photo: iStockPhoto

The infection spreads in cats through fleas. Bartonella builds up in the animals' salivary glands.

"Cats are predators by nature, and they always hunt alone. That requires silent stalking, so they constantly lick their fur and claws to remove their scent. Because of this instinct, infected cats always have traces of saliva with Bartonella on their claws," says infectious disease doctor Yulia Boiko.

People usually become infected through scratches, small cuts, or cat bites. Saliva from a cat that gets into an existing wound on your skin can also pass on the bacteria.

"Cats often lick their owners' hands. That's how many infections spread. Even petting an infected cat with a palm with tiny cuts can transmit the bacteria," says Boiko.

Her colleague, infectious disease doctor Olha Laziuk, points out that infection most often happens through contact with kittens. Their immune systems are still immature, so the bacteria circulate among them longer. A strong, healthy kitten may clear the infection or not catch it at all. But even without symptoms, a kitten can release the bacteria in its saliva or through scratches.

Research shows that owners of kittens under one year old face a 15 times higher risk of infection than owners of adult cats. Kittens are more playful, so scratches and bites are more common. Bites or scratches from kittens raise the infection risk 27 times, and fleas on a kitten raise it 29 times.

Cats usually carry the illness lightly, or without any symptoms. But once Bartonella enters a human body, it can cause real trouble.

The disease spreads to humans through scratches, minor cuts, or cat bites. Stock photo: iStockPhoto

In people, the disease often goes unnoticed, but the classic symptoms appear 3 to 30 days after contact with a cat:

• Redness, swelling, and pain at the scratch site, sometimes with pus.
• Enlarged lymph nodes (often under the arm or in the neck).
• Fever lasting for weeks.
• Headache, weakness, fatigue.
• Sometimes, it's only a high temperature in children with no apparent cause.
• The bacteria can sometimes affect the eyes, liver, spleen, or even the nervous system.

Who's most at risk?

• People with weakened immune systems (HIV, cancer, post-transplant).
• Pregnant women (due to possible complications).
• Children under 5.

Diagnosis is confirmed through serology or PCR testing. In most cases, the illness is mild and goes away on its own. In more severe or prolonged cases, doctors prescribe antibiotics and anti-inflammatory treatment.

Olha Laziuk recalls:

"A woman came to us with a swollen, painful lymph node in her groin, about the size of a quail egg. She said an aggressive cat had scratched her. First, she had a fever, then the swelling. Tests confirmed cat scratch disease. She recovered after antibiotic and symptomatic treatment."

Yulia Boiko adds, "In my practice, a patient came in a few days after being bitten by his cat. His right hand was swollen and painful. Because of cat scratch disease, he had to take antibiotics. He recovered, but it's a good reminder: even your cat can be an infection source."

The overall prognosis is good. Antibiotic treatment usually lasts 5–10 days, sometimes up to 14 days with additional therapy. Bartonella, however, can cause serious problems, especially in young children and people with weak immune systems.

At the Okhmatdyt children's hospital in Lviv, Ukraine, doctors recently reported two cases where cat scratches left 4–5-year-old boys permanently blind in one eye. In one case, the cat scratched the boy directly in the eye. In the other, it probably scratched his arm or another body part, but the infection spread and caused irreversible vision loss.

Teach children to interact with pets gently, without force. Stock photo: iStockPhoto

Loving cats is perfectly normal and wonderful, but it's important to know the basics of hygiene around animals. With proper care, pets aren't a serious threat, especially if you:

• Wash your hands after contact with cats, don't let them lick you, clean scratches properly, and don't kiss cats (especially, don't let children do it).
• Don't assume a house cat is always "safe."
• Treat your cat regularly for parasites. Flea treatments are essential even for indoor cats; fleas can infest shoes, bags, or clothing.
• Teach children not to play roughly with pets. If a child is scratched, clean the wound with an antiseptic immediately and monitor their health closely.
• Don't ignore even mild symptoms. Redness, swelling, enlarged lymph nodes, eye pain, or changes in vision mean you should see a doctor immediately.

What increases the risks:

• Letting a cat lick your face or open wounds — risk of cat scratch disease, pasteurellosis.
• Sleeping with cats — if they carry fleas, fungi, or worms, they can spread infection.
• Kissing cats — bacteria from saliva and fur are risky, especially if your immune system is weak.

See a doctor after cat contact if:

• Lymph nodes become swollen or painful for several days.
• You develop a fever.
• You notice unusual symptoms or start feeling worse.

Even more helpful solutions!

Infectious disease doctor and therapist Olha Laziuk. Photo courtesy of the expert

"Parents often ask me: How risky are cats for children or pregnant women? Cat scratch disease rarely complicates pregnancy, but there is a risk of bacteria spreading in the blood and harming the fetus. Besides, the risks include not just cat scratch disease, but also toxocariasis, worm infections, and fungal diseases," says Olha Laziuk.

So, cat scratch disease is not the only illness cats can carry. Experts list several others:

1. Toxoplasmosis. It is transmitted through cat feces (for example, cleaning a litter box) or, more rarely, through contaminated sand. It is especially dangerous for pregnant women, as the parasites can cause severe fetal damage.

"But if a cat never goes outside, doesn't eat raw meat, and has lived indoors for years, the risk is tiny. In fact, people get toxoplasmosis more often from undercooked meat than from cats," says Yulia Boiko.

That's why you should never "taste-test" raw ground meat.

2. Salmonellosis can spread through litter boxes, feces, or even pet food. It is dangerous for children and people with weak immune systems.
3. Pasteurellosis. This disease spreads through bites or cat saliva and causes skin inflammation, sometimes with serious complications.
4. Ringworm. This fungal infection is especially common in kittens and is passed through contact with fur or skin.
5. Worm infections: roundworms, toxocara, and others. The risk rises if you neglect hygiene or skip deworming. Worms are especially dangerous for children.
6. Rabies. This deadly disease is transmitted through bites, scratches, or saliva, most often from stray animals. Read more about rabies here.

At first glance, these sound scary. In truth, there's no need to panic or avoid pets. The key is balance: love your cats, but also take care of your health. Wash your hands, visit the vet regularly, and teach kids how to treat animals gently. For pregnant women, caution — not isolation — is the rule.

Epidemiologist and infectious disease doctor Yulia Boiko. Photo courtesy of the expert

Yulia Boiko sums it up:

"I also have a cat. He's a family member, our child's favorite, and our fluffy stress reliever when we have hard days. But as a doctor, I always remember that love for animals shouldn't mean forgetting common sense. We give him regular parasite treatments, vaccinations, and keep hygiene rules at home. No licking faces, we clean scratches right away, and we use gloves for litter box cleaning. These are simple habits, but they keep risks as low as possible. The balance between caring for your pet and protecting your health is achievable. And it doesn't get in the way of love — it actually makes it safer and longer-lasting."