Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: The main sign of skin allergies in dogs is itching: licking paws, scratching, rubbing the face, and chewing at the belly, armpits, or rear. Other signs include red skin, recurring ear infections, hair loss, and skin infections. Where the itching happens gives clues: flea allergy focuses on the lower back and tail base, while environmental and food allergies usually affect paws, face, ears, armpits, and belly.
Common signs
- Licking or chewing paws, rust-colored saliva staining
- Scratching, rubbing the face on furniture or carpet
- Red skin, rashes, or bumps
- Recurring ear infections
- Hair loss, darkened or thickened skin over time
- Scooting or licking the rear
- Skin odor or greasy skin from secondary yeast or bacteria
Patterns by allergy type
- Flea allergy: lower back, tail base, and back legs
- Environmental (atopic dermatitis): paws, face, ears, armpits, belly. Often starts between 6 months and 3 years, and may be seasonal at first
- Food allergy: similar areas, often year-round, sometimes with digestive signs
When to see a vet
- Itching that disrupts sleep or lasts more than a few days
- Open sores, odor, or discharge
- Recurring ear infections
- Hives or facial swelling (urgent)
More: skin allergy diets and food trials.
Sources
- Olivry T, et al. Treatment of canine atopic dermatitis: 2015 updated guidelines from the International Committee on Allergic Diseases of Animals (ICADA). BMC Vet Res. 2015
- Merck Veterinary Manual: Atopic dermatitis in dogs
- Merck Veterinary Manual: Flea allergy dermatitis
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.