Print / Save PDF Print take-home sheet

New Dog Owners · Health

Dog allergies: signs to watch and what to do next

7 min read

TL;DR

Persistent scratching, paw licking, head shaking, or red skin deserves a veterinary check. Fleas, skin or ear infections, food reactions, and environmental allergies can look alike. A symptom diary helps your vet work through the possibilities.

  • Note where and when symptoms happen; photos can help show changes.
  • Ask your vet about parasite prevention and checks for skin or ear infection.
  • Do a food elimination trial only with a veterinary plan; allergy blood tests do not diagnose food allergy.
  • Sudden collapse, trouble breathing, or rapidly developing severe signs need emergency veterinary care.

  • Scratching, rubbing, chewing, or licking the skin or paws more than usual
  • Red skin, hair loss, sores, or repeated skin problems
  • Head shaking, ear discomfort, or recurring ear problems
  • Sometimes vomiting or diarrhea alongside skin signs

Itching is a sign, not a diagnosis. An itchy dog may have parasites, infection, or another condition even if allergies seem likely. Contact your veterinarian when signs persist, recur, or disrupt sleep or normal activity.

Get urgent help

If your dog has difficulty breathing, collapses, becomes suddenly very weak, or develops rapidly worsening symptoms after a sting, medication, or food exposure, seek emergency veterinary care immediately.

Next in Health and Safety

Frequently asked questions

Does itching mean my dog has a food allergy?
No. Fleas, infection, other parasites, and environmental allergies can also cause itching. Your vet can work through the causes.
Will an allergy blood test tell me which food to avoid?
No. Food allergy is investigated with a vet-directed elimination diet and food challenge. Environmental allergy testing has a different role.

Sources

Sources checked 29 September 2026