Cat open sores

Question
Hi Jessica,
I adopted a cat from a friend at probably 9 months old. She found her a few months before that in an abandoned chicken house. She is about 1 1/2 yrs old now. She has repeatedly broken out in sores down her back, back legs and inner thighs. They start out like a very small bump that apparently itches, she starts licking, it turns into a nasty scab, the scab last a coulple days and then she licks it off and it starts all over again. The vet has checked her with the flourescent light, skin scrape, feline luk, etc.... He has given her a steroid shot called a "depo" (I believe thats what they call it) and that makes her stop licking them and they heal up. The shot last about 4 weeks and then the small bumps come back in the EXACT same locations and the whole mess starts over again. I am worried that these shots every month are really going to affect her internal organs and my vet doesnt know what else to try other than allergy testing. Have you ever heard of this before??

Answer
Hi Melanie,

This sounds like miliary dermatitis. "Miliary" refers to millet, a small seed that is similar in appearance to the small bumps that initially arise with this type of rash.  These rashes often escalate to scabs as the cat scratches at the itchy bumps. The rash can be widespread, and this can lead to body-wide scabbing. Miliary dermatitis is usually an allergic reaction. The most common allergen is the flea. Just one bite can cause a reaction for 8 weeks. But food allergies can cause miliary dermatitis, too.

Depomedrol does control the symptoms of miliary dermatitis, but you're right to be concerned about life-long use. While most cats tolerate it well, it does just mask the symptoms of the underlying disease, and as cats age, it can cause complications if cats have certain common health issues like diabetes or heart problems. It's not known to cause these problems, but it can exacerbate them.

I think it would be better to go ahead with allergy testing than to blindly rely on the Depo. Of course, if she isn't on any flea preventative, try this first, and keep it applied very consistently. It's okay to apply flea treatments a couple weeks apart if you suspect she is not fully protected. If there is no improvement in her condition after a couple of months of flea treatments, I think it's worth it to go ahead with allergy testing. Then, you can hopefully avoid food ingredients that can trigger this response. Antihistamines can also be helpful and less harmful than steroids like Depomedrol.

Good luck!
Jessica