Puppy Biting and Teething: Why It Happens and What to Do
Veterinary references checked with PetHealth+ · Last reviewed June 2026
Why puppies bite
Mouths are how puppies investigate the world and play with littermates. When they leave the litter, they must learn that human skin is more fragile than fur. Biting also intensifies when puppies are teething — sore gums drive chewing behaviour. Lack of sleep, overstimulation, and insufficient mental exercise amplify nipping.
Teething timeline
Puppies have 28 baby teeth that begin falling out around 3–4 months as 42 adult teeth erupt. You may find teeth on the floor or notice blood on toys — both are normal. The worst chewing often occurs between 4 and 6 months. Provide varied textures: rubber Kongs, frozen carrots (supervised), and commercial teething toys.
What works: redirection and consequences
Keep a toy in every room. When teeth touch skin, offer the toy and praise chewing it. If biting continues, calmly end interaction — stand, fold arms, look away. Return attention when the puppy settles. Consistency across all household members matters; mixed messages confuse puppies.
Avoid rough hand play that mimics wrestling — it rewards biting. Never slap mouths or hold jaws shut; fear erodes trust and can worsen aggression.
Bite inhibition
Allow gentle mouthing initially while teaching pressure limits. Yelp or say “too bad” when a bite hurts, then pause. Puppies learn to soften their jaws — a skill that prevents serious injury if an adult dog ever snaps in pain. Aim for zero contact on skin by adulthood, but gradual softening comes first.
When to seek help
Consult a vet to rule out pain if biting suddenly worsens. See a certified behaviourist if you observe stiff body language, hard staring, resource guarding, or bites that break skin consistently despite training. Early intervention prevents escalation.
Related guides: How to care for a puppy · Leash training a dog · Crate training a dog
Frequently asked questions
Why does my puppy bite my hands constantly?
Puppies explore with their mouths and play-bite littermates — they need to learn that human skin is off limits through consistent redirection.
When do puppies stop teething?
Baby teeth fall out from around 12–16 weeks; adult teeth are usually fully in by 6–7 months, though biting may continue until training succeeds.
Should I yelp when my puppy bites?
A brief 'ouch' and pausing play can help some puppies; others get more excited — redirect to a toy and reward calm instead.
Is aggressive puppy biting normal?
Hard bites with stiff body, growling, or guarding are not normal play — seek a qualified behaviourist if redirection fails repeatedly.