Bad Breath

Our 3 year old daughter’s breath is often bad. What smells should we look for, are there any that we should watch out for?
Nicholas Godfrey – Oakville, Ontario

Boy blowing bubbles.

Dr. Greene’s Answer:

Most kids would go out of their way to avoid eating garlic or onions, yet it is not unusual for a child to wake up with very smelly breath. Throughout the day, a child’s saliva, swished by the mouth muscles, washes away unwanted debris. As soon as a child falls asleep, saliva production plummets, and the muscles relax. The longer a child sleeps, the higher the bacterial count in the mouth rises, resulting in “morning breath.”

In children, smelly breath that persists throughout the day is most often the result of mouth-breathing, which dries out the mouth and allows the bacteria to grow. Children who consistently breathe through their mouths might have colds, sinus infections, allergies, or enlarged tonsils or adenoids blocking the nasal passages, so a visit to the pediatrician is in order. Thumbsucking or sucking on a blanket can also dry out the mouth. Tonsillar stones, collections of food and bacteria that get stuck in the crevices of the tonsils, can also cause bad breath.

To improve most cases of bad breath, the goal is to decrease mouth bacteria and increase saliva. The better your daughter’s toothbrushing technique, the smaller number of bacteria will be present. Make after-meal brushing a habit. Use a timer to help her brush for at least two minutes. Be sure she brushes her tongue. You might also try a rotary electric toothbrush. I do not recommend mouthwashes or fluoride rinses in young children, since they tend to swallow them. Breath mints may mask the problem, but don’t get at the source. As your daughter gets older, sugarless sour candy or sugarless chewing gum can get the saliva flowing and get those mouth muscles moving.

If the problem persists, she should see her doctor. Bad breath in children that doesn’t respond to the above measures should be investigated. Here is a list of some very uncommon, but telltale, odors (mostly from Mace, Goodman, Centerwall, et al: The child with an unusual odor. Clinical Pediatrics 15:57-62, 1976). Take a whiff:

  • Acetone – diabetes or acetone, alcohol, phenol, or salicylate ingestion
  • Ammonia – some types of urinary tract infections, or kidney failure
  • Asparagus – eating asparagus (very unusual in children;>))
  • Bitter almonds – cyanide poisoning
  • Cat’s urine – odor of cats syndrome (beta-methyl-crotonyl-CoA-carboxylase deficiency)
  • Celery – Oasthouse urine disease
  • Dead fish – stale fish syndrome (trimethylamine oxidase deficiency)
  • Fresh-baked bread – typhoid fever
  • Foul – tonsillitis, sinusitis, gingivitis, tonsill stones, lung abscess, or dental cavities (some of these are actually quite common)
  • Garlic – arsenic, phosphorus, organic phosphate insecticides, or thallium poisoning
  • Horse-like (also described as mouse-like or musty) – phenylketonuria
  • Rancid butter – odor of rancid butter syndrome (hypermethionemia and hypertyrosinemia)
  • Raw liver – liver failure
  • Sweaty socks – odor of sweaty feet syndrome (Isovalryl CoA dehydrogenase deficiency)
  • Sweaty socks – odor of sweaty feet syndrome II (Green acyldehydrogenase deficiency)
  • Violets – turpentine poisoning

Three-year-olds often stuff items in their noses, and then forget about them. When my son Kevin was three, he put five peas up his nose before anyone found out! Watch for the combination of smelly breath and a smelly, yellow nasal discharge — especially from one nostril. You and I might not think of stuffing peas up our noses, but three-year-olds think outside the box!

Dr. Alan Greene

Dr. Greene is the founder of (cited by the AMA as “the pioneer physician Web site”), a practicing pediatrician, father of four, & author of Raising Baby Green & Feeding Baby Green. He appears frequently in the media including such venues as the The New York Times, the TODAY Show, Good Morning America, & the Dr. Oz Show.

  1. nosipelo

    I have a 3 year old girl with a very bad breath especially in the morning. Is there any remedy that I can do to help him

    • sanjeev

      My three years and 8 month daughter has bad breath and bad smell in her urine in (at the same time). Sometimes there is not any bad smell in urine and mouth, but sometimes, after it starts again, it persists for few days. We noticed it two times. Please tell us! Is there any problem?

  2. Dawn

    My 6 year old recently got metal caps on a couple of her teeth and sealants. Since her caps were put on, she has gotten very bad breath. It seems that every week it gets worse. When I floss between her capped teeth the foul smell is there on the floss. I asked her dentist but they never give me an answer although I tell them it didn’t start until the caps. Thet tell me maybe its her diet but I have been careful with that. Should I take her to another dentist for another opinion? I feel bad for her because kids can be mean and we dont know what to do about her bad breath.

  3. Kimberly

    I have a 7 year old who has perfect teeth (other than them coming out like a normal 7 year old), but her breath is bad and she is getting teased in school!

  4. Comfort

    My 3 year old boy have a very bad smell all say. He has three of his teeth decayed. His dentist suggested removal but I thought he’s too young to go through all that pain. Could it be the possible cause of the smelly breath because it’s all day. I’m confused please help.

    • Allison

      I work as a dental assistant in a pediatric dental office. If you’re taking your son to a general dentist I suggest you take him to a pediatric dentist, because we would only recommend pulling out children as young as 3s teeth if the teeth were infected. If these teeth are infected there would be a bubble beside the teeth, or if there is large black decay that is too big for the tooth to be saved and the teeth will become infected. But yes, decayed or infected teeth would make your Child’s breath smell bad.

      • Allison

        But if you take your child to a pediatric dental office we may be able to save the teeth, with a filling or a crown.

  5. Andrae

    Just a quick question about my baby boy who is 10 months old. We have noticed that his breath smells like poo. I think it is genetic because I (the dad) have a problem as well. I’m a bit concerned as his breath seems too smelly all the time.

  6. laura deleon

    615 W 186 ST APARTAMENTO 3B
    helloo, i have a kids with very bad breath, all day…he is 11years old…I take him to the dentist….brusth 2 time…..mouthwash…and bad breath cont


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