Why is my dog itchy? Allergies, fleas or infection
Most chronic itching in Australian dogs is environmental allergy (atopic dermatitis), with grass pollen, dust mite and chicken protein as the top three triggers. The hard part is telling allergies from a flea problem, a yeast infection, or all three at once. Below: how to do the diagnosis at home in 15 minutes, what the vet adds with a skin scrape, and how Apoquel ($40 to $80 a month), Cytopoint ($80 to $150 a month) and immunotherapy compare.
Allergy vs flea vs infection at home
Three big causes of chronic itching, with different patterns:
- Flea allergy. Itches mostly at the base of the tail, the back of the legs and the belly. Often hot spots near the rump. A flea comb pulled through the fur near the tail base catches dirt that turns red on a wet tissue (flea poo).
- Environmental allergy (atopic dermatitis). Itches face, paws, ears, armpits, groin. Often worse in spring and summer. Affected dogs lick paws constantly, rub face on furniture.
- Food allergy. Itches face and ears too, plus chronic loose stool or vomiting. Year-round, doesn't follow seasons.
- Bacterial or yeast infection. Rancid smell, greasy coat, sometimes pustules or scabs. Usually secondary, on top of an underlying allergy. Hard to settle without treating both.
Most chronically itchy dogs have a combination, often atopic dermatitis with secondary infection. The flea, tick & parasite treatment guide covers the flea side, this page focuses on allergy and infection.
The top three Australian triggers
- Grass and tree pollens. Worst in spring and early summer. Couch grass, ryegrass, plantain, paterson's curse. Affected dogs are markedly worse after walks in long grass.
- House dust mite. Year-round but often peaks in autumn (more sleep time on bedding). Affected dogs are itchy at home rather than just outside.
- Chicken and beef proteins. The two most common food allergies in Australian dogs (chicken being more common). Lamb and fish are sometimes used as “hypoallergenic” alternatives.
When the vet visit pays off
For an itchy dog, the high-value vet steps are:
- Skin scrape and cytology ($80 to $150). Confirms whether there's bacterial or yeast infection. Treating the wrong thing wastes weeks.
- Wood's lamp / fungal culture ($30 to $150). Rules out ringworm, especially if you have other pets or kids. The ringworm in cats guide covers the feline side.
- Elimination diet trial (8 to 12 weeks). The only reliable way to confirm food allergy. A novel-protein hydrolysed diet for the trial period.
- Intradermal allergy testing ($400 to $700, specialist dermatologist). For dogs heading toward immunotherapy.
- Blood-based allergy testing ($150 to $300). Less reliable than intradermal but useful for some food allergies.
Treatment options compared
- Apoquel (oclacitinib). Daily tablet. Fast-acting (24 to 48 hours). $40 to $80 a month. Effective in 70 to 80 per cent of allergic dogs. Long-term safe in most.
- Cytopoint (lokivetmab). Monthly injection. Fast-acting (24 to 48 hours). $80 to $150 per shot. Targets the specific itch cytokine. Suits owners who don't want daily medication.
- Atopica (ciclosporin). Daily tablet. Slower onset (4 to 6 weeks) but very effective for severe cases. $80 to $150 a month.
- Antihistamines (Polaramine, Claratyne). Cheap ($10 to $20 a month) and worth trying for mild cases, effective in around 30 per cent of allergic dogs.
- Immunotherapy (allergy shots or sublingual drops). Builds tolerance over 1 to 2 years. $1,000 in year 1, less thereafter. Long-term remission in 60 to 70 per cent of treated dogs.
- Steroid tablets/injections. Cheap and fast but with side effects. Used for short-term flare control, not long-term management.
What it all costs in Australia
Tell people when not to wait it out: persistent itch (more than a fortnight) needs a vet, the longer it goes the more secondary infection adds to the cost. A $130 vet visit at week 2 is cheaper than the $400 specialist visit at month 4 for the same problem.
Straight answers
How can I tell allergies from fleas?
Flea allergy itches mostly at the base of the tail, the back of the legs, and the belly. Environmental allergy itches face, paws, ears, armpits and groin. Food allergy itches face and ears too, and often comes with chronic loose stool. A flea comb resolves the first guess in 2 minutes.
What are the most common allergens for dogs in Australia?
Grass and tree pollens (especially in spring/summer), house dust mite (year-round), and chicken and beef proteins (the food side). About 80 per cent of allergic dogs in Australia have at least one environmental trigger.
Is allergy testing worth it?
Intradermal skin testing at a vet dermatologist is the gold standard, $400 to $700 once. Blood-based serology is cheaper but less reliable for environmental allergens. Worth it for dogs needing immunotherapy ('allergy shots') treatment.
How does Apoquel compare to Cytopoint?
Apoquel is a daily tablet, around $40 to $80 a month, fast-acting (24 to 48 hours). Cytopoint is a monthly injection, $80 to $150 per shot. Both work in around 70 to 80 per cent of allergic dogs. Cytopoint suits owners who don't want to medicate daily.
Can I treat itchy skin at home?
Mild flares respond to oatmeal baths, omega-3 supplements, and vacuuming pollen out of bedding. Persistent itch (more than a fortnight) needs a vet, the longer it goes the more secondary skin infection adds to the problem.
Is there a cure for allergies?
Not really, but immunotherapy ('allergy shots' or sublingual drops) trains the immune system over 1 to 2 years and produces long-term remission in 60 to 70 per cent of treated dogs. Cost is around $1,000 in year 1, less thereafter.
Most itchy dogs have a manageable allergy that responds to one or two medications plus environmental controls. The skill is matching the medication to the dog and being patient with the elimination diet. Related: flea, tick & parasite treatment, ringworm in cats, dog grooming. Information here is general and isn't a substitute for veterinary advice.