A dog who scratches every evening or licks the feet until they become red might have an allergy, but itching does not identify a single cause. Fleas, mites, bacterial or yeast infections and environmental or food reactions can look surprisingly similar.
Start with the pattern
When did the itching begin? Is it seasonal? Are the ears involved? Does your dog receive effective flea prevention? These details help the veterinarian distinguish allergic skin disease from parasites and secondary infection. Even a dog with few visible fleas may have flea allergy dermatitis.
Common allergy categories
Environmental atopy can cause recurrent itch, inflamed paws and ears. Food allergy is possible but is not diagnosed reliably by random blood or saliva food-sensitivity panels. A carefully supervised elimination diet may be recommended when appropriate. Dogs may also develop yeast or bacterial infections from repeated licking and scratching, which require their own treatment.
What happens at the appointment
The clinician may use flea combing, skin scraping, skin cytology or ear cytology, along with a thorough history. Allergen testing generally helps select ingredients for immunotherapy after atopy has been diagnosed; it does not by itself prove that a dog has atopy. Treatment can combine parasite control, infection management and targeted itch relief.
When to seek care
Bleeding skin, painful sores, ear pain, marked swelling or rapidly worsening symptoms warrant a prompt appointment. Facial swelling, collapse or breathing trouble is an emergency. See sudden itching in dogs and what an online vet can assess.
Veterinary source
AAHA: 2023 Guidelines for Allergic Skin Diseases in Dogs and Cats
For education only. A veterinarian must diagnose infections, parasites and allergies before choosing medication.
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.