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A Golden Retriever chewing at an itch on its side

My dog keeps biting himself but no fleas: what could it be?

10/14/2026 | Written by Everfur Team

You've parted the fur, checked the base of the tail, run the comb through. No fleas. And he's still at it: chewing a back leg, nibbling his flank, scratching until you say his name.

Here is the short answer. When there are no fleas to see, the usual reasons are allergies (to things in the air or in his food), a skin infection that set in on irritated skin, sore anal glands, or a habit that grew from boredom or worry. They often overlap, and you can't tell them apart by looking. What you can do is watch for patterns, write them down, and ask a vet before putting anything on his skin. A video visit is a good place to go through the pattern. If his face swells, he has hives, or he's struggling to breathe, go to an ER vet now.

Why is my dog so itchy? The usual suspects

VCA Animal Hospitals lists the most common causes of itching in dogs as flea allergy, seasonal allergies (atopy), food allergies, contact dermatitis from things like soaps and perfumes, and mites. Fleas can be hard to spot, so a clean coat doesn't always rule out a flea allergy. Beyond that:

  • Allergies to the environment. The Merck Veterinary Manual says signs are usually seasonal but may happen all year, and that the feet, face, ears, front legs and belly are the most frequently affected areas.
  • Food. VCA calls food allergy one of the most common allergies known to affect dogs. It can show up as itchy skin, paws or ears, or an upset stomach.
  • Skin infection on top of the itch. Merck notes that bacterial and yeast infections commonly develop as a result of skin inflammation. The scratching breaks the skin, and an infection keeps the itch going.
  • Anal glands. VCA says the first sign is often scooting, and some dogs lick or bite at the base of the tail instead. Skin allergies have been proposed as a contributing factor.
  • Habit, boredom or worry. VCA says repeated licking and chewing can start with a medical problem such as a skin disorder, then become a habit, and that stress, anxiety or too little enrichment can play a part. A vet rules out the medical causes first.

What you can safely check at home

Look, note and photograph. Nothing more.

  • Where. Paws, ears, belly, armpits, base of the tail, one back leg?
  • When. Worse at night, after walks, in certain months, after a bath?
  • Food. What he eats, including treats and chews, and anything new lately.
  • Paws and ears. Licking his paws, shaking his head, or both? Our post on why dogs lick their paws goes further.
  • The skin. Redness, scabs, hair loss, a greasy or flaky coat, a musty smell.
  • His day. More time alone, less exercise, a change at home.

Take a photo of each spot in daylight. Itchy skin often looks calm by the time of the appointment.

What can I put on my dog to relieve itching?

Nothing, until a vet says so. That includes creams, sprays, shampoos, oils, home mixes and anything made for people. Skin that's already broken reacts to things healthy skin shrugs off, and a product that hides the itch can hide the clue a vet needs.

The same goes for pills. Some human allergy products aren't safe for dogs, and a vet sets the dose for the dog in front of them. For the bigger picture, see what can I give my dog for allergies. Ask a vet first.

Two more to skip. Don't squeeze his anal glands yourself. And don't switch his food on a hunch: VCA describes an elimination diet as 8 to 12 weeks on a strict diet with no other foods, treats or supplements, and Merck notes that blood and skin tests aren't reliable for food allergy. Plan it with a vet.

When it's an in-person vet today

A video visit is great for the pattern. It isn't for these. Go to your regular vet or an ER vet today if you see:

  • Swelling of the face or muzzle, hives, or trouble breathing
  • Raw, weeping or bleeding skin that is spreading
  • A painful, red, hot swelling beside the anus (VCA describes this as an anal sac abscess)
  • A dog who is limp, won't eat, or seems very unwell

For a poison, call ASPCA Poison Control at 888-426-4435. We're not for emergencies.

Why it keeps coming back

Here is the frustrating part. The itch calms after a visit, and then it's back in six weeks.

Itch is usually a pattern. Merck describes atopic dermatitis as a lifelong condition that needs long-term management and regular veterinary exams, and says fleas and infections can set off flares. Food, season and skin infections can take turns. One clinic visit sees one day, and the pieces live in different places: last year's notes, the food change from spring, the weeks at the lake.

That's the old way's problem. It runs one appointment at a time, with a wait for each, and nobody reads the whole story first.

What a video visit does

A video visit with Dr. Ellen's team is built around the pattern. Here's how it goes.

  1. The records get read first. Upload past visits, notes and lab results once, and the whole history is there before the call starts. That means every itchy spell, not just this one.
  2. They look at the skin on camera. Video can show where he itches, how the coat looks and how he reacts when you touch the spot.
  3. They work through the pattern with you. Where, when, which season, what he eats, and whether the itch comes with scooting or stress.
  4. They tell you what needs hands-on care. Video can't scrape the skin, look at skin cells under a microscope or check the anal glands. If that's the right next step, you hear it plainly, and why.
  5. Your regular vet gets a summary. It goes to the vet who knows him, so everyone is working from the same history.

Visits are scheduled, and most are scheduled within 48 hours. In California you see a vet, and prescriptions are possible when they're right. In every other state it's a wellness visit with Dr. Ellen or a vet tech on her team: advice, a plan, and what to ask your regular vet. A video visit can't promise an answer or a prescription, because some itching needs hands-on care. It can make the next step clear.

Book a vet visit

Before your visit

  • Photos or a short clip of each itchy spot, in daylight
  • A rough timeline of flare-ups, and what you were told
  • His food and treats, and his flea and tick product
  • Anything you've put on his skin, and when
  • Your regular vet's name

Out of the loop

What wears owners down is the loop: the itch calms, then it comes back. A team that reads the whole history can help you see the pattern and decide what comes next.

Book a vet visit

Unlimited free vet visits with membership. Plus $50 off your first prescription in California.

FAQ

Why is my dog biting himself if he doesn't have fleas?

Often it's allergies to something in the air or in his food, a skin infection that followed the itch, sore anal glands, or a habit that grew from boredom or worry. These overlap, and a clean coat doesn't always rule out a flea allergy. A vet sorts out which are in play from the history and the skin.

Why is my dog so itchy all of a sudden?

A new season, a new food, a new product, or an infection on irritated skin can all bring on a sudden itch. Write down what changed and when. If it lasts more than a few days, the skin is broken, or he can't settle, have a vet look.

What can I put on my dog to relieve itching?

Nothing, until a vet says so. Creams, sprays, shampoos and human products can irritate skin that's already sore, and some aren't safe for dogs. A vet looks at the skin first, then picks what's right for your dog.

Can a dog be allergic to his food?

Yes. VCA says food allergy is one of the most common allergies in dogs. The way to find out is a careful elimination diet, not a blood test. Plan it with a vet.

Can I see a vet online for my dog's itchy skin?

Yes, for the pattern. Dr. Ellen's team reads your records, looks at the skin on camera, goes through the history with you and says when your dog needs hands-on care. In California that's a vet visit, with prescriptions possible; in other states it's a wellness visit.

Sources