Frenchton Dogs, Size and Health

By Kosar Koohi

Updated 5 November 2026

Almost every frenchton comes with a promise attached: that it breathes better than a French Bulldog. The claim is why the cross exists, and it holds up often enough to be worth something. It is not a guarantee, and plenty of these puppies grow up with the airways their Frenchie parent has.

So the useful questions are less about the breed than about the individual dog in front of you. Like the Cavoodle and the Puggle, this is a deliberate cross rather than a breed with a standard behind it, a distinction this guide to mixed breed and designer dogs unpacks properly.

What Is a Frenchton?

A frenchton is a French Bulldog crossed with a Boston Terrier, bred mainly to soften the Frenchie's breathing difficulties while keeping its personality. Most adults stand 11 to 16 inches at the shoulder and weigh 15 to 30 pounds, with a short, smooth coat that sheds lightly year round. Lifespan is usually 11 to 15 years. No major registry recognizes the cross as a breed, so there is no official standard for size, color or build.

Why Breeders Crossed a Frenchie With a Boston Terrier

The pairing is older than the name. Frenchie-to-Boston crossings were recorded as early as 1900, and both parents trace back to the same nineteenth century bulldog stock. Breeding under the frenchton label picked up in the United States from the 1990s, as French Bulldog popularity climbed and so did the vet bills behind it. The Frenchie now sits near the top of the most popular dog breeds in Australia, and demand on that scale pulls crosses along with it.

The Boston Terrier carries a slightly longer muzzle and a leggier frame, so adding it back in should, on average, open the airway a little. On average is the operative phrase: both parents are flat faced, and a puppy can inherit a short muzzle twice over. Anyone weighing up the parent breeds instead of the cross will get more out of this comparison of the French Bulldog and the Boston Terrier.

Frenchbo, Froston and the Other Names

The same dog is listed as a Frenchbo, a Faux Frenchbo Bulldog, a Boston Frenchie or a Froston. None of them mean anything different.

How Big a Full Grown Frenchton Gets

A full grown frenchton is compact and muscular rather than delicate, with real weight on a small frame. That puts the cross among the best apartment dogs, where low stamina counts for more than square footage.

Adult Weight, Height and When Growth Stops

Expect 11 to 16 inches at the shoulder and 15 to 30 pounds, females usually at the lighter end. Dogs that take after the Frenchie sit low and wide; those leaning Boston stand taller and carry less bulk, and littermates land at either end.

Most reach adult height by nine to twelve months, then fill out through the chest until around eighteen, so the first year with a puppy covers most of the growing. A breeder quoting an adult weight for an eight week old puppy is offering a hope, not a measurement.

Which Parent the Puppy Takes After

This matters more than color or size, and it is worth judging yourself. Watch the puppies play and then rest. Look at how far the muzzle projects, how open the nostrils are, and whether a puppy still breathes noisily a minute after stopping. One with a visible muzzle and wide nostrils has better odds than a flatter littermate. Ask to see both parents moving rather than posed, and listen to them.

Brindle, Merle and the Coat Colors to Question

Brindle, fawn, black, white, cream, seal and pied all turn up, in solids and combinations, since both parent breeds bring a broad range. Any of them is fine. Coat color says nothing about whether a dog is healthy.

Merle is the exception, because it does not occur naturally in either parent breed and arrives through other bloodlines. Two merle parents risk puppies with hearing and eye defects, part of why merle sits awkwardly among the dogs that carry blue eyes. Merle on both sides is a reason to walk away, and blue, lilac and anything sold as exotic deserves the same caution. When color leads the advertisement, the airway rarely came first.

Is There Such a Thing as a Fluffy Frenchton?

Occasionally, yes. The recessive long coat gene sits in the French Bulldog population, so a carrier parent can produce a feathered puppy in a short coated litter. It changes the grooming and nothing else, as this guide to the fluffy French Bulldog explains. A long coat on a flat faced dog does make hot weather less comfortable.

Health Problems Inherited From Both Parent Breeds

Here is the honest version. Crossing two breeds widens the gene pool, which helps with conditions caused by a single recessive gene. It does nothing about problems caused by body shape, and body shape is where this cross's trouble lives.

Breathing Is Still the Headline Risk

Both parents are brachycephalic, so a frenchton can inherit narrow nostrils, an overlong soft palate and a windpipe too small for its body. Together these are brachycephalic obstructive airway syndrome, and the signs are loud breathing, snorting, tiring quickly, restless sleep and, in bad cases, collapse.

Snoring is common enough here that owners stop hearing it. Noise is not the measure, though. Breathing rate during deep sleep is, and this guide to French Bulldog breathing problems sets out what to count. Mild cases do well on weight control and sensible walks. Others need surgery to widen the nostrils or shorten the palate, and doing it young often prevents worse later. Walk on a harness rather than a collar either way, so nothing presses on a throat already working hard.

Spine, Knees and Eyes

Short legs and a compact back make intervertebral disc disease a real risk, most of all in dogs built like the Frenchie parent. Screw tails often sit above malformed vertebrae, so that corkscrew is worth asking about. Keep jumping off furniture out of the routine, and one of these dog ramps saves the landing.

Patellar luxation, where the kneecap slips out of its groove, shows up as a skipped step or a brief hop. Juvenile hereditary cataracts arrive from the Boston side and have a simple DNA test. Prominent eyes make scratches, ulcers and cherry eye likelier.

Skin, Folds and Weekly Ear Checks

Food and environmental allergies are common, announcing themselves as itching, recurring ear trouble or paws that never stop being licked. Facial folds need wiping and drying regularly, since a damp fold against warm skin is where irritation starts. Lift both ear flaps weekly and look for redness, dark wax or a sour smell.

Health Tests to Ask a Breeder About

Hybrid vigor is no substitute for testing. Ask for results on both parents, in writing:

• An airway or BOAS assessment, ideally a functional grading rather than a glance
• Patella evaluation on both parents
• Eye certification, plus a DNA result for juvenile hereditary cataracts
• Spine imaging where either parent has a screw tail
• Hearing testing if merle appears anywhere in the pedigree

Frenchton Lifespan and What Shortens It

The usual frenchton lifespan is 11 to 15 years, a respectable run for a flat faced dog and longer than many French Bulldogs manage. Genetics set the ceiling. Daily life decides how close a dog gets to it.

Weight is the biggest lever an owner holds, and it is rarely framed strongly enough. Extra pounds crowd an airway that was already narrow, load a vulnerable back, and push harder on knees that already slip. A lean dog breathes better, moves better and recovers from heat faster, three problems softened by the unglamorous habit of measuring meals.

Temperament and Life at Home With a Frenchton Dog

Affectionate, funny, and never further than one room away. This cross wants to be included in whatever is happening, and takes a closed door personally. The Boston side brings more spark and more interest in a toy; the Frenchie side brings the comic timing and the sofa habit.

They are not a reactive breed by nature. When one starts growling or lunging, pain is the first thing to check rather than the last, for the reasons this piece on aggression in French Bulldogs works through.

Are Frenchtons Good Family Dogs?

Generally, yes, and the sturdiness helps. A 20 pound dog copes with family noise better than a toy breed does. The limits are physical rather than temperamental: no rough play, no small hands lifting them, no jumping down from furniture.

How Long They Can Be Left Alone

Not as long as most households would like. Both parent breeds bond hard, so a home empty all day is a poor match. Build alone time up in small steps and keep departures dull. Both parents appear in this piece on dog breeds prone to anxiety.

Daily Care, Exercise and Heat Safety

Grooming is close to effortless: a weekly brush, a bath every month or two, nails every few weeks. The daily work on this dog is temperature and air, not coat.

Exercise a Flat Faced Dog Can Handle

Two or three short walks a day, around half an hour in total, plus play indoors. Jogging, long hikes and rough dog park sessions are off the list for life, not just puppyhood. Scent games and puzzle feeders tire this dog out more reliably than distance.

Keeping a Frenchton Cool

Heat is the emergency risk, and it arrives fast. A short muzzle cannot cool air efficiently, so panting does less work than in other dogs. Heavy panting at rest, drooling, wobbling or refusing to walk all mean stop, cool the dog, then call a vet. These ways to keep a dog cool in summer belong in place before the first warm week.

Finding Frenchton Puppies and Spotting a Bad Breeder

Demand for frenchton puppies has outrun the number of people breeding them carefully, which is the problem in one sentence. A good breeder asks as many questions as they answer and lets you meet the mother where the litter was raised.

Walk away from a litter with no health results for either parent, where the mother cannot be seen, where color leads the advertisement, where a deposit is hurried, or where several crosses are on offer at once.

Rescue and Adoption Routes

Plenty need rehoming once the vet costs land, and both French Bulldog and Boston Terrier rescues take in the crosses. An adult also arrives with its breathing already audible, which removes the biggest unknown. The case for going this way sits in this piece on adopting a rescue dog.

Cornell's Riney Canine Health Center has a clear overview of brachycephalic obstructive airway syndrome that gets the questions ready before meeting a litter.

A well bred frenchton is a lovely small dog: steady, funny, devoted, easy to look after. The cross can improve on its Frenchie parent, but only when a breeder aimed at the airway rather than the look. Ask about that first, and keep asking.

About the author

Kosar Koohi

Editor at Pretty Fluffy

Kosar is the editor of Pretty Fluffy. Many of the site’s topics start with real questions from life with her Maltese, Yuki. The answers come from veterinary sources and research, written in plain language for everyday dog owners.

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