Cat Scratch Disease

Today, most people own at least one pet whom they consider to be a part of the family. We are very attached to our pets, and try to provide them with the best nutrition and health care that we can possibly afford. As pet owners, we must remember that some very damaging illnesses can happen by neglecting simple hygiene rules with our pets, or in our homes. One of these diseases, that typically go unnoticed in human beings, is Bartonella infection.

“Cat Scratch Disease, in human beings, is caused by the organism Bartonella, which is spread from cat to cat by fleas” said Dr. John August, professor of feline internal medicine at Texas A&M College of Veterinary Medicine & Biomedical Sciences. “The Bartonella organism infects the red blood cells and the cells lining the blood vessel walls.”

Many cats who are exposed to fleas appear to be infected with Bartonella organisms, without any clinical signs.

“When fleas feed on cats, which is called having a ‘blood meal’, the Bartonella organism grows inside the flea” said August. “The flea will eventually pass the blood meal as feces, and the ‘flea-dirt’ contains the Bartonella organism.”

If flea-dirt is located on a cat’s nail and then the cat scratches a person, the contamination is transferred within the scratch.

“Most people diagnosed with Cat Scratch Disease do not have any clinical signs” noted August. “Some may develop illness of a wide variety, including fever and lymph node tenderness in the area closest to where the scratch occurred. The lymph node soreness and fever may last for several days, although some people develop enlarged lymph nodes that can last for weeks or months.”

In a typical case of Cat Scratch Disease, a person will visit the doctor after feeling feverish, lethargic, and having headaches and lymph node tenderness.

“If there is an infection in the scratch, it will not be noticed until five to ten days after the scratch occurred” said August. “It is not until seven to ten days after noticing an infected scratch that you will start to experience lymph node discomfort, and at that time you may start feeling sick.”

Cat Scratch Disease can occur after the mildest of scratches. CSD cases are most often seen in children, because they tend to play with kittens, which are more likely to scratch and have fleas.

“Cat Scratch Disease becomes a serious problem when someone with a poorly functioning immune system is scratched and infected with the Bartonella organism” said August. “CSD can cause serious problems which affect the brain, eyes, liver, spleen, and bones. People who have contracted HIV should be cautious around cats of unknown background, because Cat Scratch Disease can cause serious disease in those individuals.”

In temperate climates where fleas are common, about 25 percent of cats are thought to be infected.

“The best method of prevention is to keep fleas off your cat” said August. “The only way that Bartonella organisms can be transferred between cats is through fleas, therefore try to use a very good flea control; especially in kittens. Another way to help keep children from getting the disease is to teach them how to play responsibly with kittens.”

When a child contracts Cat Scratch Disease it can be worrying for a parent who is unfamiliar with the disease. Symptoms of fever and swollen lymph nodes often cause parents to think that their child has a more serious disease. The good news is that people rarely get Cat Scratch Disease more than once.

“Many people with Cat Scratch Disease will recover without any help from antibiotics, but for others, antibiotics shorten the length of the illness. Those with serious disease such as AIDS may require intensive treatment” said August. “Still the outlook is very good; within the last month there have been advancements with more sensitive and accurate ways of diagnosing cats who might be infected. Researchers at the College of Veterinary Medicine at North Carolina State University have recently commercialized new types of diagnostic testing to determine if cats and dogs are infected.”



Pet Talk is a service of the College of Veterinary Medicine & Biomedical Sciences, Texas A&M University. Stories can be viewed on the Web at Suggestions for future topics may be directed to