- Cat Scratch Disease (CSD) is an infection caused by bacteria in a cat’s mouth delivered by a scratch or bite.
- A simple cat bite can carry a high risk of infection.
- The disease causes redness, swelling and flu-like symptoms.
- If scratched or bitten, quickly wash the area with soap and water; seek medical treatment if symptoms persist or worsen.
- Captain Obvious says, “Avoid stray or feral cats.”
- Keep your furry family member updated on vaccines.
As many cat lovers know, the prospect of getting scratched is in Chapter 1 of the feline ownership manual. In many instances, this is a result of healthy play and an accepted part of being a cat parent.
Recently, one of our loyal Cabbagetown Pet Clinic clients was cat-sitting for his mother over the Easter long weekend. The cat is a feisty, 1 year-old that tends to have (overly) playful tendencies, including the tactical use of razor-sharp claws. Our client was well aware of this, but having been scratched many times before, he felt that the risk of infection from light play was VERY low.
Apparently, the cat’s mood changed and playfulness turned to ire (surprise…lol!), resulting in a series of scratches over both hands. Unmoved by this outburst, he doused his hands in hydrogen peroxide and washed them thoroughly with soap and water.
Later that evening, he noticed swelling and tenderness on his left knuckle but thought nothing of it. The next morning, the swollen area had become larger, but he still (remarkably!) didn’t find this a source of concern. Only after an afternoon of cold sweats, back pain and high fever did the prospect of an infection ever cross his mind. Nonetheless, he waited one more sleepless night to see if there would be improvement.
That was a mistake.
The next morning, it had become abundantly clear that an immediate trip to the local ER was a forgone conclusion, as his left hand swelled like an inflated rubber glove. As it turns out, not only were there scratches on the left hand, but also a distinct puncture wound very near to the infected area – mostly likely caused by the cat’s bite. Cellulitis had begun to take hold.
What followed was a tetanus shot, bloodwork and six days of a strong, broad-spectrum antibiotic administered through an IV at the local ER, followed by another 10 days of an oral antibiotic to treat the infection. Yes, this was quite an ordeal, but the story had a happy ending – the infection was defeated. However, another day (or two) of neglect could have resulted in something much worse.
What is Cat Scratch Disease (CSD)?
Cat Scratch Disease (also known as *cat scratch fever*) is an infection caused by the bacteria Bartonella henselae carried in cat saliva. This is one of the most common bacteria in the world. CSD is generally mild, but people with weakened immune systems and the young tend to be at more risk of developing a serious infection.
However, Bartonella henselae is not the only bacteria in a cat’s mouth. Others include Pasteurella multocida which is a type of bacteria commonly found in the mouth. A research study (science geek out alert!) from 2013 showed that Pasteurella multocida is the most common organism isolated from both cat and dog bites. Bite wounds tend to be highly aggressive and exposure to this bacterium can cause a more significant infection – such as cellulitis – after a bite or scratch. This can have much more serious consequences, as our devoted client discovered.
Where does the bacteria come from?
It is believed that cats acquire these bacteria from fleas.
Cat Scratch Fever is transmitted when a cat carrying the infection:
- delivers a deep scratch that draws blood
- administers a bite* that punctures the skin
- licks an open wound
* Cats have sharp, slender canine teeth that easily pierce deep tissues, bones and joints. These quick-healing puncture wounds – injected with saliva and bacteria – seal in harmful bacteria and create a dead space for infection to flourish.
How do you know if a cat bite is infected?
What are the symptoms?
Common symptoms of infection from a cat bite include:
- redness and/or inflammation
- warmth over the affected area
- a bump or blister near the bite puncture
These indicators typically do not require medical attention. However, keep a close eye for an escalation of the symptoms.
7 Signs of a Serious Cat Bite Infection:
- A bite or scratch that becomes inflamed and tender within a few days and worsens over time
- Sore or swollen glands under the arms (hand wound) or in the groin (lower leg wound)
- Pus leaking from a blistered wound
- Loss of feeling near the wound
- Red or discoloured streaks close to the wound
- Discomfort and/or restricted mobility in your hand
- Flu-like symptoms including:
- reduced appetite
- joint pain
- fever or chills
- night sweats
The symptoms of Cat Scratch Disease may look like other medical conditions. Unlike our client, seek medical treatment immediately if you experience these complications.
What cats carry the highest risk of infection?
- stray and feral cats
- flea-infested cats
- kittens (less than 1 year old)
- outdoor cats that hunt
What should I do after being bitten by a cat?
Follow these 4 steps:
- Clean the wound thoroughly with soap and water. An antibiotic ointment can be also applied, but avoid strong disinfectants as this may damage the skin. Vigorous scrubbing of the wounds may damage tissue and delay healing.
- With a sterile, absorbent dressing, apply direct pressure to the wound to control any bleeding** and keep covered.
- Monitor for symptoms (see above)
- If symptoms persist or get worse, see a physician as soon as possible. Left untreated, a serious infection can develop within twenty-four to forty-eight hours.
** If the injury is a bite wound, you may not experience much bleeding. Cats have hypodermic-like teeth that can easily pierce soft tissues. This mechanism creates a tiny break that heals rather quickly – trapping the bacteria under the skin. This is bad.
How Do You Treat Cat Scratch Fever?
In most instances, Cat Scratch Disease clears up on its own without treatment within a few weeks. Most cases of cat scratch fever are mild – a doctor may not always have a prescribed treatment plan.
To help alleviate pain and discomfort at home, an over-the-counter pain reliever can be taken, such as Ibuprofen or naproxen. Applying a heat compress to the affected area may also bring some relief.
If your symptoms are moderate to severe and don’t go away in a month or two, antibiotics (or any other medical interventions) may be required. In rare cases, the CSD infection can travel to your bones or other organs. This requires more aggressive medical care.
The hand is an extremely vulnerable part of the body. It contains many important structures – such as tendons, joints, blood vessels and nerves – covered only by a thin soft tissue sheath. So, it should come as no surprise that the needle-like, canine teeth in cats – infused with various types of bacteria – can cause serious damage. In extreme cases, a deep, skin-penetrating bite can lead to serious medical consequences – including death.
As the ER physician of our client made perfectly clear – if this happens again, DO NOT WAIT TO SEEK MEDICAL HELP!
Hard lesson learned.