Dog itching (pruritus)
Pruritus (itching) in dogs is among the most common reasons for veterinary dermatology consults. Causes vary widely — from fleas to food allergies to hormonal conditions.
⚠ Emergency signs
- Open wounds, bleeding, visible infection
- Head/muzzle swelling (anaphylaxis)
- Skin broken from excessive scratching
- Scratching preventing sleep
- Extensive inflammation (over 30% body)
Common causes
- External parasites: fleas (most common), ticks, sarcoptes, demodex
- Food allergies: proteins from chicken, beef, dairy, soy, eggs
- Environmental allergies (atopy): pollen, mites, mould, grass — seasonal or year-round
- Contact dermatitis: shampoos, detergents, materials
- Secondary bacterial or fungal infections: develop on irritated skin from repeated scratching
- Hormonal conditions: hypothyroidism, Cushing's — in older dogs
Typical itch zones
Ears (otitis), paws (constant licking), groin, armpits, base of tail (suggestive of fleas), face.
What you can do at home
Check for fleas with a flea comb (especially at the tail base). Inspect skin — redness, crusts, lesions, hair loss. Note when scratching appears (after walks = environmental atopy, after meals = possible food allergy). Hypoallergenic shampoo baths once a week if already diagnosed as atopy.
External parasiticides
Discuss the right product with your vet (Bravecto, NexGard, Frontline, Advantix, etc.). DO NOT use human or cat medications on dogs — some are toxic. Environmental treatment (carpets, beds, crate) for 3 months to break the flea cycle.
EMERGENCY SIGNS
- Open wounds, bleeding, visible infection
- Head or muzzle swelling (acute allergic reaction — anaphylactic)
- Dog is breaking the skin from excessive scratching
- Scratching prevents sleep
- Extensive inflamed skin (over 30% of body)
Diagnosis at the vet
Clinical exam + skin scrape (looking for mites). Microbiology culture (bacteria or fungi). Food elimination test (8 weeks of mono-protein diet, if suspecting food allergy). Intradermal allergy testing (for environmental atopy). Blood work (for hormonal causes in older dogs).
Frequently asked questions
How do I recognise fleas?
Intense scratching especially at tail base. Check with flea comb. Look for tiny black dots (flea droppings) that turn red on damp paper (digested blood).
How long does atopy treatment last?
Atopy is chronic — managed lifelong. With regular parasiticides, hypoallergenic shampoos, appropriate diet and sometimes medication (Apoquel, Cytopoint, steroids in flares), dogs maintain good quality of life.
Does hypoallergenic diet work?
For true food allergies yes — but the elimination test requires 8 strict weeks (NO treats, NO scraps). If scratching decreases, reintroduce one ingredient and watch for recurrence.
Can I give my dog Loratadine or other human antihistamine?
Only with vet approval — doses differ and some human antihistamines are dangerous for dogs.
⚠ Information for educational purposes. For diagnosis and treatment, consult a veterinarian.