Q: My grandmother feeds several cats on her back porch. My mom, who is not a cat person, is worried about the cats spreading cat scratch fever to my grandmother and making her sick. I have heard of this condition in people but I don’t really know much about it. Is my Grandmother really at risk or is my mom overreacting? My grandmother really likes her cats.
A: Cat scratch fever is a real disease in people that they catch from infected cats. As an extremely young girl growing up in the ‘70s, I remember liking a song by Ted Nugent called “Cat Scratch Fever” that had a strong electric guitar part. It kind of sticks in your head if you remember the tune. And here I am a few decades later, writing about the disease in cats. Who would have thunk it? Kudos to Ted.
Cat scratch disease is actually an infection caused by a bacteria called Bartonella. The bacteria is spread by fleas that live on cats and some dogs, too.
Fleas leave flea dirt on the animals they live on. It’s the pepper-looking black specks we find on cats that have fleas when we part their hair and look at their skin. Flea dirt is a combination of flea excrement, dried cat blood and larvae. Yuck!
When cats scratch due to fleas, they get the flea dirt in their claws. If the fleas are infected, those claws carry the flea dirt and bacteria to people and other cats through scratch wounds.
In people with cat scratch disease, a few things will happen to make them feel ill. A strong healthy person will get a red raised pimple like lesion at the site of the scratch. Then two to three weeks later, they will feel some lymph node swelling in that area and develop a fever. It is a self-limiting disease, meaning it will resolve on its own, but the lymph nodes can stay enlarged for a longer time.
Now, if the person scratched by the infected cat is immunocompromised, this is definitely a more serious condition. Immunocompromised people include the very young, very old and people struggling with chronic debilitating diseases like cancer.
Bartonella causes more serious conditions, like splenic enlargement, encephalitis or a brain inflammation/infection and even heart valve issues. All of these conditions are life threatening to this population of people.
Cats also can become sick with the disease like people do. But in cats, the bacteria does not always cause overt signs of disease, making carrier cats hard to recognize. We have found that Bartonella in cats can clinically cause fever, heart issues, eye inflammation, reproductive failure, pain and lymph node enlargement too, similar to people.
The problem is that the bacteria only circulates in the body of an infected cat periodically. So if a cat is sick and we test for Bartonella with a blood test, we may or may not get a positive result even if the cat is a carrier.
The best way to test for Bartonella in the cat is to do multiple blood cultures. Hopefully you can get a positive on one of those tests. A positive is a positive. A negative needs to be repeated.
If we do get a positive culture, then treatment is indicated in the cat. Because Bartonella is a bacteria, it is luckily susceptible to several antibiotics. Doxycycline, clavamox and baytril all are effective in eradicating the bacteria. Treatment is needed for a minimum of three weeks in the cat. Treatment is generally recommended for all cats showing signs of the disease and cats living with immunocompromised people.
Cat scratch disease is a true public health concern, and the Centers for Disease Control and Prevention has come out with these guidelines on how the prevent the disease:
- If you are an immune-suppressed person, you should only adopt healthy kittens less than 1 year old.
- If you are immune-suppressed, you should not adopt from shelters or multicat homes.
- If you are immune-suppressed, you should keep your cats indoors always and keep their claws trimmed regularly.
- Wash all cat scratches well immediately with warm soapy water.
- You must practice year-round flea control on all cats.
So, if your grandmother is a healthy person and not classified as immune-suppressed, then I would think that she could go forward with feeding her cats that she loves so much. But if she is immune-suppressed, then I would suggest she stop interacting with them and have another family member take over.
Please share with both your mother and grandmother the facts about cat scratch disease so they too can learn to be safe around outdoor cats.