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You’ve probably heard of the disease. It’s known as cat scratch disease, or sometimes cat scratch fever. The disease gets a fair amount of media attention and cats are often blamed as the culprit for the infection. However, there’s much more to the story.


What Is Cat Scratch Disease?


Cat scratch disease is more likely to pose a threat to you than it is to your cat. In people, cat scratch disease usually starts with a swelling (known as a papule) at the site of infection/contamination. The local lymph node may swell and become somewhat painful. Flu-like symptoms may develop. In most cases though, the infection will resolve without incident.


Immunosuppressed people can suffer much more serious effects from cat scratch disease, however. In these people, the infection may invade the body leading to a number of potential syndromes, including encephalitis, heart valve infection, and other conditions.


The disease is caused by a bacteria known as Bartonella henselae, which is carried by fleas.


How Do People Get Cat Scratch Disease?


People become infected with the organism when a cat scratch is inoculated with infected flea dirt. If your cat's claws become contaminated with flea dirt, you may be exposed to the disease if your cat subsequently scratches you. Bite wounds can also be contaminated and cause cat scratch disease. However, the common denominator is the flea. Without fleas, there is no contamination of any wound with flea dirt and no infection.


What If My Cat Is Infected with Bartonella henselae? Will He Get Sick?


The vast majority of infected cats remain asymptomatic. You may never even know that your cat has become infected. There has been a link made between a condition of the mouth known as stomatitis and infection with Bartonella henselae. However, the significance of this link is not known and it may not be significant.


Most infected cats never require any treatment for disease. Treatment of infected cats does not reduce the potential for disease spread to people.


How Can I Protect Myself and My Family from Cat Scratch Disease?


The best form of prevention is flea control. Because fleas are required for the disease to spread, keeping your cat free of fleas is essential to protecting yourself and your family.


Avoiding scratches and bites by learning to play safely with your cat can help as well. Learn to recognize the changes in your cat’s body language that indicate that your cat is becoming aggravated and likely to attempt to scratch or bite. Never play with your cat with your bare hand. Use a toy or suitable substitute to avoid accidental scratches.


In addition, cats younger than one year are more likely to be infected. If someone in your family is immunocompromised, you may want to consider adopting a more mature cat to reduce the potential for disease. Healthy adults with strong immune systems are rarely at risk though.


Now you know the truth about cat scratch disease. Though cats are often involved in its spread to infected people, the cat is not solely responsible. Fleas play at least an equally important role in the spread.


Dr. Lorie Huston



Image: Jagodka / Shutterstock



Other Articles You Might be Interested In:

Cat Scratch Fever


Cat Scratch Disease in Cats


Comments  2

Leave Comment
  • Cat Scratches
    01/06/2014 06:27pm

    "Never play with your cat with your bare hand."

    I cannot believe that so many people play with kittens with their bare hands and are then astonished when the adult cat continues with this method of play. Duh.

  • A Couple More Resources
    01/10/2014 01:22pm

    Hi Dr Huston and all,

    I don't know if you've ever heard talks by Dr Mike Lappin (Colorado State Univ) who is one of the leading experts on bartonella (along with Dr Breitschwerdt at NC State). Dr Lappin is very dynamic and I can still hear him in my mind saying ... "It's not the cat! It's the fleas, it's the fleas, it's the fleas! ... Don't kill the cat, kill the fleas!!!" :-) There are cases of people with bartonella henselae who have not had any contact with cats. The key is always the fleas ... and infected flea poop (flea dirt) getting in an open wound (any cut or scratch). I think fleas get infected by biting infected cats, so cats are generally around ... but the transmission to humans is usually via the infected flea dirt (or from infected cat blood).

    If anyone wants more in-depth info on bartonella henelae and "cat scratch disease" ... the AAFP did a good "Panel report on diagnosis, treatment, and prevention of Bartonella spp. infections" published in their Journal of Feline Medicine and Surgery back in 2006. It is a little dated but is by some of the leading experts (corresponding author is Dr Lappin) and I think most of the info is still current. It's in an easy to read "Q&A" format with 32 questions, and is available for free on the internet for anyone who is interested at:

    Also, Dr Breitschwerdt, who is probably THE leading authority on bartonella, created a company that is licensed to test human blood ... and has developed special techniques that can detect various types of bartonella in humans. He has discovered that there are also less common signs of bartonella infection in humans, some chronic (including insomnia, chronic fatique, etc) that physicians aren't aware of and don't think of bartonella as a possible cause. Some species of bartonella are very hard to detect but Dr Breitschwerdt's company, Galaxy Diagnostics, has special techniques to detect various types of bartonella. Anyone interested in learning more about that and Dr Breitwchwerdt's work can browse the Galaxy Diagnostic's website at:

    Stephanie in Raleigh

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