A bit of doggy smell is normal; breath that makes you turn away isn't. In the vast majority of cases the cause is in the mouth: plaque, tartar and inflamed gums. Here's how to work out what's going on, what really works and when it's time for the vet.
In short
A dog's bad breath almost always comes from the mouth: plaque turns into tartar and the bacteria under the gums produce the smell. Periodontal disease is the disorder vets diagnose most often in dogs, and small and older dogs are the most affected. What works is brushing every day plus professional cleaning at the vet: no food, wet or dry, replaces them. If the breath smells of urine, sweet or rotten, or your dog drinks a lot, eats less or loses weight, book a vet visit.
In most dogs the cause is in the mouth. After every meal plaque, a film of bacteria, forms on the teeth. If nobody removes it, within days it hardens into tartar, which builds up along the gum line. There the bacteria inflame the gum (gingivitis) and over time attack the tissues that hold the tooth in place: that's periodontal disease, and the smell you notice is produced by those bacteria.
It isn't rare. In a study of more than 22,000 dogs seen by UK vets, periodontal disease was the most frequently diagnosed disorder: 12.5% of dogs in a single year. When teeth are examined under anaesthesia the figures rise to between 44% and 100%, because much of the damage below the gum line can't be seen with the mouth closed.
Small dogs, flat-faced dogs and older dogs. In the same UK study the risk of periodontal disease fell as body weight rose, and it was higher in Toy Poodles, King Charles and Cavalier King Charles Spaniels and, surprisingly, Greyhounds. Flat-faced (brachycephalic) breeds had 25% higher odds than other dogs, and the risk grows with age for every dog.
The type of smell helps you tell where it comes from. It isn't a diagnosis, but it tells you how quickly to act.
| Smell | What it can mean | What to do |
|---|---|---|
| Fish, mildly rotten | Plaque and tartar; sometimes the anal glands, if your dog often licks its rear | Vet check and dental cleaning |
| Urine, ammonia | Can be a sign of kidney disease, especially if your dog drinks and urinates more | See the vet soon, with blood and urine tests |
| Sweet, fruity | Can point to uncontrolled diabetes, especially with more thirst and weight loss | See the vet now |
| Strongly rotten, with blood or swelling | Infection, a broken tooth, a foreign body or a growth in the mouth | See the vet |
| Poo | Almost always your dog is eating faeces (coprophagia) | Pick up stools straight away and talk to your vet |
If bad breath comes with yellowish gums or eyes, vomiting or weight loss, the liver may be involved: that needs a vet visit too.
By removing plaque every day, and tartar once it has formed. The American Animal Hospital Association's dental care guidelines for dogs and cats put the toothbrush first:
They cover the smell, they don't remove the cause. Parsley, mint, coconut oil or apple cider vinegar can at most mask the breath for a while, but they don't remove plaque or tartar: if the cause is in the mouth, the smell comes back. Baking soda is abrasive and isn't designed for a dog's mouth (more on that here).
One thing never to do: use human toothpaste. Many contain xylitol, a sweetener that can make a dog's blood sugar crash quickly, as the US FDA warns.
A little, but not enough to replace the toothbrush. Three studies point the same way:
The last two studies were run by researchers at a large pet food maker. The Polish survey also found that daily brushing, or a daily dental chew, reduced problems in every group. There are dental diets and chews designed for the job and approved by the VOHC, but they're not the same as an ordinary kibble. In practice, whatever your dog eats, wet, dry or fresh, for the teeth it's the toothbrush that counts.
When it doesn't come from the mouth, or comes with other signs. Book a vet visit without waiting if:
Let's be straight with you: no food replaces the toothbrush, ours included. Pappa Fresh recipes are made for everyday feeding: real meat as the first ingredient, vegetables, a vitamin and mineral supplement, no preservatives, no colourings, no meat meals. For the mouth, pair them with two minutes of brushing a day and a vet check once a year.
Two minutes, portions calculated for your dog, 30% off your first order.
Most of the time because of plaque and tartar: the bacteria in the mouth produce a smell that recalls fish. Sometimes the anal glands are involved, if your dog often licks its rear. Ask your vet to check both the mouth and the glands.
It's common but not normal. Periodontal disease increases with age, and in a senior dog breath that changes suddenly, especially if it smells of urine or something sweet, can be linked to the kidneys or to diabetes. A vet visit with blood tests is needed.
Parsley, mint or coconut oil can at most cover the smell. The only remedy that tackles the most common cause is removing plaque: daily brushing with dog toothpaste, plus professional cleaning when tartar is already there.
A little: in studies, dogs on kibble had slightly less sulphur in their breath and slightly less plaque than dogs on wet food, but their gum health was the same. What works is the toothbrush and dental products with the VOHC seal, which have shown it in studies.
When it smells of urine, ammonia or something sweet, when your dog drinks a lot, eats less, vomits or loses weight, or if there's blood, swelling or pain in the mouth. In those cases call your vet straight away.
Written by the Pappa Fresh editorial team from published veterinary studies (see sources). Not a substitute for your vet's advice.
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