Teeth, Gums and the Gut: Why Dental Health Is a Digestive Issue

He’s gone fussy. Picks at his food, walks away, comes back later. Drops bits on the floor. Chews on one side. Sometimes he yelps at a hard biscuit and you assume he caught it awkwardly.

Nobody’s looked in his mouth for three years.

Periodontal disease affects the large majority of dogs over the age of three, and it is comfortably the most under-diagnosed painful condition in pet dogs. It also sits at the very top of the digestive tract, which means it shapes everything downstream — what a dog can eat, how well he chews it, and what arrives in the stomach.

The scale of it

Estimates vary with the study, but most put periodontal disease in something like eighty per cent of dogs by three years old. It is not a condition of very old dogs; it’s a condition of ordinary adult ones.

It starts as plaque, a soft bacterial film. Within days that mineralises into tartar, which is hard, rough and impossible to remove with a toothbrush. Bacteria accumulate in the pocket between tooth and gum, the gum becomes inflamed, and over months to years the attachment holding the tooth in place is destroyed.

The end point is a loose, painful tooth in an infected socket. Dogs rarely stop eating because of it. They adapt — chew on the other side, swallow food whole, avoid hard things — and owners read the adaptation as fussiness or old age.

Where the gut comes in

Two connections, and both matter.

Chewing is the first stage of digestion. A dog with a sore mouth bolts his food, swallowing larger pieces and more air. That means more work for the stomach, more swallowed air, more wind, and often looser stools because things are arriving less broken down than they should be.

And the mouth is where the digestive tract begins. Every mouthful of saliva a dog swallows carries oral bacteria into the stomach and intestines. A mouth harbouring substantial infection is delivering that load continuously, all day, every day.

There’s a growing body of work on the oral microbiome and how it interacts with the gut, and while it’s early, the direction is fairly clear: a mouth in poor condition doesn’t stay a local problem.

Which is one reason gut support and dental care belong in the same conversation rather than separate ones. Daily Probiotic Dog Treats support the population downstream, and they’re doing that job against whatever the mouth is sending down — so sorting the mouth out is part of the same project rather than an unrelated errand.

What you’d actually notice

Bad breath. The most common sign and the most normalised. Dog breath should not be offensive. If you flinch when he yawns, that’s bacteria, not personality.

Red, swollen or bleeding gums, particularly at the margin where gum meets tooth.

Brown or yellow tartar, worst on the big teeth towards the back of the upper jaw.

Eating differently. Slower, fussier, tilting the head, chewing on one side, dropping food, preferring wet to dry.

Pawing at the mouth, face rubbing, or reluctance to have the head touched.

Drooling, sometimes tinged with blood.

A swelling below the eye. That’s usually an abscessed upper carnassial draining through the cheek, and it’s frequently mistaken for a bite or a sting.

Loose or missing teeth.

Weight loss in an older dog, which gets attributed to age.

Why dogs don’t tell you

The question every owner asks: surely he’d let me know?

Mostly not. Dogs are poor at signalling chronic, slowly worsening pain — there’s no evolutionary advantage in advertising weakness, and pain that develops over two years never produces a moment of obvious change.

What you get instead is gradual adaptation. Vets see this constantly: a dog has eight teeth out, and the owner reports two weeks later that he’s playing like a puppy and they hadn’t realised how flat he’d become.

That’s the honest test of whether the pain was real.

Looking properly

Takes ten seconds and almost nobody does it.

Lift the lip on one side, towards the back. That’s where tartar accumulates first — the upper premolars and molars. Look at the gum line specifically rather than the tooth surface.

Then the other side. Then, if he’ll allow it, open the mouth briefly and look at the inside surfaces and under the tongue.

Do it weekly. You’re looking for change: new tartar, redder gums, anything broken, anything that wasn’t there before.

If he objects strongly, that’s information too. Reluctance to have the mouth handled in a dog who used to tolerate it often means it hurts.

Brushing, which genuinely works

The only thing that reliably removes plaque before it mineralises. Everything else is secondary.

Daily is the target. Every other day is worthwhile. Once a week achieves very little, because plaque mineralises within roughly two to three days.

Use dog toothpaste. Human toothpaste contains fluoride and often xylitol, and dogs swallow it.

Build up slowly. A week of just letting him lick the paste off your finger. Then a week of touching the outside of the teeth with a finger. Then a soft brush or finger brush, a few teeth at a time, working up over a month.

Focus on the outer surfaces and the gum line. That’s where the disease starts. The inner surfaces matter far less.

Keep it short and pay him afterwards. Thirty seconds done willingly beats two minutes wrestled.

Start with a puppy if you possibly can. A dog who has had his teeth brushed since twelve weeks accepts it as ordinary.

What else helps, and how much

Dental chews. Some genuinely reduce tartar and some are biscuits with marketing. Look for products carrying veterinary dental approval, and count the calories, because most are substantial. They’re an adjunct to brushing, not a substitute.

Raw bones. Divisive. They do clean teeth effectively. They also fracture them — slab fractures of the upper carnassial from weight-bearing marrow bones are a classic and expensive injury. Cooked bones are never safe. If you use raw, choose softer non-weight-bearing bones and supervise.

Dental diets. Larger, differently textured kibble designed to scrape rather than shatter. Modest benefit, well tolerated.

Water additives and gels. Convenient, and generally the weakest option. Better than nothing, nowhere near brushing.

Antlers, hooves and very hard chews. Frequently fracture teeth. Plenty of vets would rather you didn’t.

Some dogs are far more prone than others

Worth knowing whether yours is in a high-risk group, because it changes how often you need to look.

Small and toy breeds are the worst affected by a wide margin. Yorkshire terriers, chihuahuas, dachshunds, poodles, cavaliers, shih tzus, greyhounds and whippets all come up repeatedly. The reason is mostly crowding — the same number of teeth in a much smaller jaw means less space, more overlap, and more places for plaque to sit undisturbed.

Greyhounds and whippets specifically have a reputation for poor dental health that goes beyond crowding and isn’t fully explained.

Brachycephalic breeds — pugs, bulldogs, boxers — have teeth rotated and crammed into a shortened jaw, often with several sitting at odd angles.

Dogs fed exclusively wet food get no mechanical abrasion at all, which matters at the margins.

Older dogs, cumulatively, because this is a disease of years rather than months.

If your dog is in one of those groups, weekly checks and daily brushing aren’t excessive — they’re the difference between one dental in his life and one every two years.

Cost, and why it’s worth budgeting for

Dentals are one of the more common significant veterinary expenses and one of the least often insured for, because many policies exclude routine dental work or require evidence of annual check-ups.

A straightforward scale and polish is a few hundred pounds. Multiple extractions, particularly of large carnassials or molars with complex roots, push it considerably higher, and full-mouth X-rays add to it. A badly affected small dog needing a dozen extractions can run past a thousand.

Two practical points. Check what your policy actually covers for dental, in writing, before you need to — a lot of owners discover the exclusion at the worst moment. And ask for a written estimate as a range, because the vet genuinely cannot know how many extractions are needed until the dog is under and the X-rays are done.

The cheaper route is prevention, and it’s a toothbrush.

The professional clean

At some point brushing isn’t enough, because tartar below the gum line cannot be removed at home.

A proper dental requires general anaesthesia. Scaling, polishing, full-mouth X-rays and probing of each tooth, with extractions where the attachment is gone. It cannot be done meaningfully in a conscious dog, and anyone offering an anaesthetic-free “dental” is cleaning the visible surfaces and leaving the actual disease untouched.

The anaesthetic worries owners, understandably, particularly with older dogs. Two things worth weighing. Modern veterinary anaesthesia with pre-operative blood work and monitoring is considerably safer than most people assume. And leaving a mouth full of infection is not the safe option — it’s chronic pain plus a persistent bacterial load, indefinitely.

Ask for a written estimate, and expect it to be a range, because they can’t know how many extractions are needed until the X-rays are done.

Afterwards

Recovery is usually quick and the change in demeanour is often dramatic.

Soft food for a few days if there have been extractions, pain relief as prescribed, and a check that he’s eating comfortably.

Then start brushing. A dental gets you back to a clean baseline; brushing is what keeps you there. Dogs who have a dental and no home care are usually back for another one within a couple of years.

Where to start today

Look in his mouth. Both sides, at the back, at the gum line.

If there’s tartar, redness or bad breath, book a dental assessment rather than waiting for the annual appointment.

Buy dog toothpaste and start the finger-licking stage tonight.

And if he’s been labelled fussy, or slowing down, or just getting old — check the mouth before you accept any of those. It’s the cheapest and most frequently rewarding thing you’ll do for an older dog, and a surprising number of “digestive problems” begin above the neck.