Dog hair loss – when should I see a vet?

Updated 2026-09-30 · 1 sources

Based on: PDSA

Book a vet visit

This is not usually an emergency on its own – contact your vet if it lasts, gets worse or your dog seems unwell in any other way. Hair loss can be caused by fleas, skin allergies, hormone disease, skin infections or over-grooming.

What to do now

What you can do now

  1. Contact your vet.
  2. Note when it started, how often it happens and what else you see.
  3. Take a photo or short video to show the vet.
  4. Keep fresh water available.
  5. Let your dog rest somewhere calm.

Don't

  • Do not give any human medicine.
  • Do not wait if it gets worse.

What it can mean

Hair loss can be linked to fleas, skin allergies and hormonal problems.[1] Other possible explanations include mites and lice, ringworm, skin infections, contact alopecia, wounds and scars, over-grooming, seasonal alopecia or inherited causes.[1] It can come with itchy skin, dandruff, bumps or scabs, patches of dark skin, or more licking and chewing than usual.[1] Alopecia in dogs is often treatable and rarely permanent.[1]

Other signs that can come with it

  • Itchy skin
  • Dandruff
  • Bumps or scabs
  • Patches of dark skin
  • More licking and chewing than usual
  • Weight gain
  • Weight loss
  • Low energy

Possible causes

  • Fleas
  • Mites and lice
  • Skin allergies
  • Hormone disease
  • Ringworm
  • Skin infections
  • Contact alopecia
  • Wounds and scars
  • Over-grooming
  • Seasonal alopecia

What the experts say

“Weight gain ; Weight loss ; Changes in appetite ; Drinking more ; Bumps or scabs ; Dandruff ; Itchy skin ; Over grooming (licking and chewing more than usual) ; Patches of dark skin ; Low energy (lethargy)”

If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

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Common questions

What can cause hair loss in dogs?

Possible causes include fleas, mites and lice, skin allergies, hormone disease, ringworm, skin infections, contact alopecia, wounds and scars, over-grooming, seasonal alopecia and inherited causes.[1]

What other signs can come with hair loss?

Other signs can include itchy skin, dandruff, bumps or scabs, patches of dark skin, more licking and chewing than usual, weight changes and low energy.[1]

Is hair loss in dogs usually permanent?

Alopecia in dogs is often treatable and rarely permanent.[1]

Sources

  1. PDSA

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages

The same page for cats →

Other symptoms in dogs

Head tiltHumping BehaviourIncreased ThirstItchingItchy Ears and Head ShakingLimping and stiffnessLoss of balanceLow energyLumpsMouth PainNystagmusOver-grooming