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Why does my dog have red blotches if he's on flea prevention?

Updated On September 23rd, 2025

My dog has flat red blotches on his skin. Could these be flea bites? I've checked and see no fleas or signs and he's on a preventative, but I wasn't sure if it was flea bites or irritation from me pulling at his fur to get dandruff out.

1 Answer

Most Helpful Answer

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Answered By Rosemary Barber, DVM

Veterinarian

Published on March 21st, 2017

Hello there! These could be flea bites for sure, although less likely if he is on a preventative, especially if it is the type of preventative that kills adult fleas, as well as stopping fleas from reproducing. This could be many other types of rash, as well, though, such as a bacterial rash, or even a form a bruising which occurs when the blood platelets are low. It is always a good idea to get a check up done with your vet, to be sure that there is nothing to worry about! Best of luck!

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