We sell this powder. It was not the product tested in the studies discussed here.
TL;DR
The best chew for bad breath is one that reduces plaque, because plaque bacteria make the smell. Choose a chew with the Veterinary Oral Health Council (VOHC) seal for plaque, tartar or both, in the right size for your dog, soft enough to dent. In studies, daily dental chews have lowered the sulfur compounds that cause bad breath. If the smell comes from tartar, gum disease or a bad tooth, no chew will fix it, and your dog needs a vet exam.
Why chews can help breath
Bad breath in dogs is mostly volatile sulfur compounds, gases made by bacteria in plaque and on the tongue as they break down protein. A chew helps in two ways: the chewing action scrapes plaque off the teeth, and some chews add ingredients that work chemically.
Studies that measured breath directly:
- A 2022 crossover study of 14 dogs, funded by Mars Petcare, tested two oral care chews against brushing and no intervention after deliberately inducing bad breath. Single chews reduced hydrogen sulfide and methyl mercaptan in the breath, and the chew designed for deeper, all-round cleaning worked best.
- A 2025 study of a honeycomb-shaped dental chew fed daily for 60 days found a 46.71% reduction in breath sulfur compounds, along with less tartar and plaque.
- A 2018 randomized trial of 60 small-breed dogs found that daily treats containing the brown seaweed Ascophyllum nodosum lowered breath sulfur compounds compared with identical treats without seaweed over 90 days, starting from freshly cleaned teeth. It was funded by Sweden Care AB, which makes ProDen products.
Why the VOHC seal is the best shortcut
The VOHC does not have a "fresh breath" category. It awards its seal only for controlling plaque or tartar, based on controlled trials. That is still the right filter, because plaque is what feeds the smell. A chew that only claims "fresh breath" may be relying on mint or parsley to cover odor.
Examples from the August 2026 VOHC list include Canine Greenies, OraVet Dental Hygiene Chews, Purina DentaLife, Pedigree Dentastix Advanced, WHIMZEES Brushzees, C.E.T. VEGGIEDENT FR3SH, Milk-Bone Brushing Chews and ProDen PlaqueOff Dental Bites. Check the exact product and size on the current list.
How to choose the right chew for your dog
- Size by weight. Use the weight range on the package. VCA warns that a chew your dog can swallow with barely any chewing does no cleaning and could be a choking hazard.
- The bend test. VCA advises that any chew should bend and "give" when compressed. VCA lists bones, antlers, hooves, ice cubes and hard nylon as the usual causes of broken teeth.
- Calories. WSAVA advises keeping treats under 10% of daily calories. Large dental chews can be calorie-dense, so reduce food or other treats to match.
- One a day. Most accepted chews are tested once daily. Giving several adds calories without proven extra benefit.
- Supervise. Especially with a new chew, and with dogs that gulp.
When a chew will not fix the smell
Chews slow new plaque. They do not remove hardened tartar, treat infected gums or fix a broken or abscessed tooth. VCA notes that once tartar forms, it needs professional scaling under anesthesia. Book a vet exam if you notice:
- Brown tartar along the gum line, or red or bleeding gums
- Dropping food, chewing on one side, pawing at the mouth or drooling
- Breath that suddenly got much worse
- A swelling on the face or under the eye
VCA also notes that kidney disease can cause bad breath, and oral tumors can too, so breath that stays bad after the mouth has been treated is worth investigating.
Better together
The most effective single habit is still daily brushing. In a 2019 randomized trial, daily brushing controlled plaque more than three times as effectively as a daily dental chew. If you can brush, a chew is an extra. If you cannot, a chew plus a VOHC-accepted water additive or food powder covers more ground. See our guides to home remedies for dog bad breath and dog water additives for bad breath.
FAQ
Do dental chews actually freshen breath?
Several have measured it. The effect depends on removing plaque, so it lasts only while you keep giving them and only if the mouth is otherwise healthy.
Are bully sticks or rawhides good for bad breath?
We found no breath studies for bully sticks. VCA recommends avoiding rawhides and bones in general because of broken teeth and swallowed chunks. One soft rawhide product carries a VOHC seal for tartar.
My dog's breath smells like fish or ammonia. Will a chew help?
Unusual smells are a reason to see the vet, not to switch chews. See why your senior dog's breath smells bad.
References
- Croft JM, Patel KV, Inui T, Ruparell A, Staunton R, Holcombe LJ. Effectiveness of oral care interventions on malodour in dogs. BMC Veterinary Research. 2022. PMID: 35513817
- Crowder SE, Berg M, Bellows J, et al. Effectiveness of a daily honeycomb-shaped dental chew in reducing calculus, plaque, gingivitis and malodor in dogs. Journal of Veterinary Dentistry. 2025. PMID: 38819379
- Gawor J, Jank M, Jodkowska K, Klim E, Svensson UK. Effects of edible treats containing Ascophyllum nodosum on the oral health of dogs. Frontiers in Veterinary Science. 2018. PMID: 30109236
- Allan RM, Adams VJ, Johnston NW. Prospective randomised blinded clinical trial assessing effectiveness of three dental plaque control methods in dogs. Journal of Small Animal Practice. 2019. PMID: 30575038
- Veterinary Oral Health Council. VOHC Accepted Products for Dogs (list updated August 2026) and VOHC protocols.
- VCA Animal Hospitals. Dental Disease in Dogs, How to choose puppy dental treats, Causes of bad breath in puppies, Oral Tumors in Dogs.
- World Small Animal Veterinary Association. Feeding treats to your dog.
For individual health questions, your veterinarian remains the best partner.
