Cat Scratch Disease: What You Need to Know

Don’t you love it when a problem is self-explanatory?

‘Cat scratch fever’ is one such condition as, ‘It does what it says on the label.’ This is people run a fever as a result of being scratched by a cat. Simple. However that simplicity belies a more complex condition so let’s take a look in more detail to see if this is something to worry about? (Spoiler alert: It isn’t… when you take common sense precautions.)

What Causes Cat Scratch Disease?

It isn’t the scratch itself that causes this illness, but a bacterium that is inoculated into the blood stream via the cat’s claws. The bacterium is called Bartonella henselae, and it mainly infects cats and sometimes dogs.

Cats pick the bacterium up either from scrapping with other infected cats (or if an infected cat washes broken skin) or by grooming and ingesting infected fleas. Indeed, it’s a common infection than you might suspect, because testing shows that up to 60% of adult cats have been or are infected with Bartonella henselae at some point in their lives.

Does Bartonella henselae make cats sick? No. There are different types of Bartonella infection, but the one that causes cat scratch disease is relatively harmless and rarely causes illness in cats. Of course there is an exception to every rule, and in extremely rare cases B. hensalae causes inflammation of vital organs such as the heart or kidney, and make the cat very sick indeed.

However, the majority of our fur-friends who come into contact with these bacteria, develop immunity, and it never bothers them again. Indeed, Bartonella hensalae would have faded into obscurity were it not for the fact that it has the potential to make people ill.

Image: RVADrewsPix via Flickr

What are the Symptoms of Cat Scratch Disease?

Another name for this condition is cat scratch fever, which gives you a strong hint about at least one of the symptoms: Fever!

In people the signs start to develop around 3 – 14 days after being scratched or bitten by a cat. The wound is often inflamed and angry looking, and accompanied by flu like symptoms such as aching muscles, fever, chills, extreme tiredness and swollen lymph nodes.

Your doctor may run diagnostic tests, but mainly to rule out other more serious conditions that can cause swollen lymph nodes, such as TB or lymphoma. However, they may have a strong suspicion of what they’re dealing with because of the ‘smoking gun’ evidence of a nasty cat scratch which looks red and sore.

What does the doctor do? In all likelihood this is a case of sending you to bed for a few days and taking things easy. Poulticing those swollen lymph nodes with warm flannels can help ease the discomfort. But those people with a healthy immune system usually fight off infection without the need for intervention. And if for any reason it’s thought that antibiotics are required, then those from the tetracycline family are effective.

Image: Jill Allyn Stafford via Flickr

Who is Most at Risk?

As with any infection, including the common cold, those people most at risk are those with a poor immune system. These include the very old or young, those on chemotherapy, or those with health problems that suppress the immune system. Sadly, this can lead to some serious complications such as a form of meningitis; but the chance of this happening is very low.

The good news is that in healthy individuals, a single episode of cat scratch disease is enough to confer lifelong immunity.

Image: Big Ben in Japan via Flickr

How do I Prevent Infection?

Simple. Wash any bites or scratches immediately afterwards, with soapy water. This is all you need do to get rid of the Bartonella henselae and drastically reduce the odds of infection.

Oh, and as a parting thought, it’s not the fierce angry feral cats you have to watch out for so much as the cute fluffy kittens. By far the biggest source of infection is those playful scratches from needle sharp claws of a kitten.