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Updated on September 23rd, 2025
Pet's info: Dog | Mixed Breed Medium (23 - 60lb) | Male | neutered | 1 year and 1 month old | 49 lbs
My dog is shedding a lot and itching a little. I got him skin application medicine for fleas and he was dewormed earlier than 3 months. He has been eating almost the same food since he was 2 months old. I have only switched to adult dog food from puppy food. Can food allergies in dogs start suddenly?
2 Answers

Answered By Dr. Melanie, BVSc MS
Veterinarian
Published on March 20th, 2018
Answered By Ricardo Fernandez, DVM
Veterinarian, Veterinary Oncology Resident
Published on August 23rd, 2017
Hi there! Thanks for using Petco Pet Education Center, formerly Petcoach! This is common with flea allergy dermatitis. It is great that you have done what needed to control the fleas. However, it sounds like Cooper is still having the clinical signs of itchiness and allergy. The reason is that even if you do not see any fleas, they could still present in small amounts. It only takes 1 flea to cause allergy signs. The other thing to consider is that usually secondary bacterial infections which happen secondary to the flea allergy can cause a great amount of itch and they need to be treated appropriately along with the fleas. I advice that you have him evaluated by your veterinarian to start therapy for the likely secondary infection and further therapy for fleas if needed based on examination. Good luck!
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