Why do other dogs react to French Bulldogs?
Part of the answer may be the way a Frenchie is built. Research since 1997 has found that breeds that look less like a wolf use fewer of the wolf’s conflict signals, that a short tail tells approaching dogs less, and that people misread flat faces more often. The first study to watch flat-faced dogs meet other dogs found they did not signal any less — but the other dogs responded to them differently.
In short
The whole chapter in a few lines. Read further only where you want to know why.
- Dogs settle most meetings with the tail, the face, the ears and the body
- A short tail and a flat face show less — whether his ears can go back is still an open question
- The first study of flat-faced dogs meeting dogs: they signaled normally, but the other dogs responded differently
- Harder to read does not mean aggressive — UK vet records point the other way
- On a walk: keep your distance, and watch the other dog, not yours
A breed summary is only a prejudice about the breed.
You can use prejudices — but get to know your own dog.
It depends on the breeding, the environment, and the dog’s own character. He may have all of the breed’s traits, some of them, or none. Every dog is his own.
1 How dogs talk: a small dictionary
Most meetings between dogs are settled before anything happens. Dogs use the tail, the face, the ears and the whole body to say “I’m friendly,” “I’m not sure about this” or “don’t come closer” — and scent tells the rest. Each signal buys a moment, and most of the time that is enough.
What the usual signals say:
| Signal | What it usually says | |
|---|---|---|
| Tail | loose, at middle height, wagging broadly | relaxed, friendly |
| high and stiff | aroused, confident — possibly a challenge | |
| low | unsure, uneasy | |
| tucked between the legs | fear — “I give up” | |
| Face | mouth open and relaxed, soft eyes | calm |
| mouth closes and goes tight | tension rising | |
| lip curl, teeth, wrinkled muzzle | a warning — “back off” | |
| a lip lick or a yawn that does not fit the moment | stress, trying to calm things down | |
| looking away, turning the head | “I don’t want trouble” | |
| Ears | forward | interest, attention, moving in |
| back | “I’m no threat” | |
| flattened against the head | fear | |
| out to the sides (“airplane ears”) | mixed feelings | |
| Body | play bow — front end down, rear end up | “this is a game” |
| weight forward, stiff | a challenge | |
| weight back, body curved, making himself small | “I’m not looking for a fight” | |
| freezing | the last warning before contact |
Dogs read these closely. In a study from Italy, dogs watched videos of other dogs wagging their tails. When the wag swung more to the left side of the wagging dog’s body, the dogs watching had a higher heart rate and behaved more anxiously than when it swung more to the right.
2 Where a Frenchie is different
Now hold a French Bulldog up to that list.
- The tail is short — a stub or a screw. There is little to raise, to tuck or to wag broadly.
- The face is flat, with a short muzzle and short lips. There is less to wrinkle, and less to see changing.
- The ears stand up. WEBSITE FINDING (Whole Dog Journal) — UNOFFICIAL FINDING: a veterinarian writing there says upright ears are easier to read than ears that hang down.
So the question about a Frenchie’s ears is not whether they stand up. It is how far back they can go, and we could not find a study that has measured it. Back and flattened are the positions that say “I’m no threat” and “I’m afraid.”
What researchers have measured, over almost thirty years, is what a dog’s shape does to his signals.
3 What four studies found
Four studies from five countries, each looking at a different piece:
| Study | What they looked at | What they found |
|---|---|---|
| 1997 UK | 10 breeds, each watched in a group of its own breed, and 15 signals wolves use in a conflict | The breeds used between 2 (Cavalier King Charles Spaniel) and 15 (Siberian Husky) of those signals. The less a breed looks like a wolf, the fewer it tended to use, and the breeds with the fewest kept mostly the signals a wolf pup already shows before it is 20 days old. French Bulldogs were one of the ten breeds, and among those that used the fewest. |
| 2008 Canada | 492 off-leash dogs meeting a life-size robot dog with a short tail, 9 cm (3.5 in), or a long one, 30 cm (12 in), still or wagging | With the long tail, dogs responded differently to wagging than to stillness. With the short tail, wagging made no difference — and larger dogs stopped mid-approach almost twice as often, 30% against 16%. The authors: a wag gets its message across best on a long tail. |
| 2024 Czechia, Hungary | People in an online survey judging Boston Terriers (flat-faced) and Jack Russell Terriers recorded in pleasant and unpleasant situations | The Jack Russells’ faces and tails told people more. The Boston Terriers were mostly read as being in a good situation — people more often took their unpleasant moments for pleasant ones. |
| 2025 Italy | 30 dogs — 14 flat-faced, 16 with medium-length muzzles — approached by a dog of one shape or the other | The flat-faced dogs did not signal less, or differently. But the dogs with medium muzzles flicked their tongues more when the dog coming toward them was flat-faced — a signal earlier research links to tense moments — and play-bowed more to dogs shaped like themselves. |
The first three point the same way: a body that looks less like a wolf, a short tail and a flat face come with fewer signals, or with signals that are harder to read. The fourth is the only one that watched flat-faced dogs meet other dogs, and it did not find that they signal less. What it found is that the other dogs responded to them differently. The authors call it the first study of its kind, with a small number of dogs, and say more research is needed.
4 Harder to read is not the same as aggressive
It would be easy to jump from here to “so that is why Frenchies get into fights.” The data does not make that jump.
The largest study of French Bulldogs in veterinary records is VetCompass, run by the Royal Veterinary College in the UK. It compared 2,781 French Bulldogs with 21,850 other dogs. French Bulldogs were far less likely to have undesirable behavior recorded by their vet, and aggression was recorded less often too — in 1.1% of the French Bulldogs and 2.3% of the other dogs.
Vet records only count what reaches the vet, and a number for a breed is not a description of your dog. What this chapter is about is not how a Frenchie feels — it is how easily that can be read.
5 What this means on a walk
If his signals can be harder to read — for people, and possibly for other dogs — a few things follow when a dog you do not know comes closer:
- Distance is the tool. A meeting that never starts does not need to be read by anyone. Leave enough room to walk past.
- Do not wait for his warning. He may already be giving one you cannot see — and the other dog may not see it either.
- You are his signal. Turning and walking away calmly says “no trouble” for both of you.
- Watch the other dog, not yours. Your dog’s face may tell you little. The other dog’s tail, ears and body will tell you more — the dictionary above works on any dog.
6 Spike: our experience
Our stories and opinions on this page are our personal experience with one dog, Spike. One dog is not the measure for every dog — for your dog, your vet decides.
“He’s a cocky dog, you know — always kicking the dirt.”
Most of this chapter is about a Frenchie who may not be able to say “I’m uneasy, back off.” Spike is the other case. With other dogs, he is often the one who starts it. He is pushy: after he pees, he kicks up the dirt with his back legs, and he tries to mount other dogs.
Our reading is that the missing signals cut the other way for him. A long-tailed dog who pushes his luck can drop his ears, wag, and turn it into a game. Spike comes in with his weight forward, his ears up and no tail to wag. He has no easy way to say “just kidding.” So we take him away early, before it builds.
He does not do it with every dog. He picks one, goes to the fence, riles that dog up and runs off — and, as far as we can tell, he enjoys having its attention. Behind a fence that costs him nothing. Without a fence he tries to climb on, and that is the part he cannot take back. Same dog, two settings.
Owners Also Ask
Why do other dogs react to French Bulldogs?
Part of the answer may be the way a Frenchie is built. Research since 1997 has found that breeds that look less like a wolf use fewer of the wolf’s conflict signals, that a short tail tells approaching dogs less, and that people misread flat faces more often. The first study to watch flat-faced dogs meet other dogs found they did not signal any less — but the other dogs responded to them differently.
Are French Bulldogs aggressive toward other dogs?
Not by the numbers. In UK veterinary records comparing 2,781 French Bulldogs with 21,850 other dogs, French Bulldogs were far less likely to have undesirable behavior recorded, and aggression was recorded in 1.1% of them against 2.3% of the other dogs. Vet records only count what reaches the vet, and a breed number does not describe any single dog.
Can other dogs read a French Bulldog’s signals?
Research is still early. In a robot-dog study, a short tail told approaching dogs less than a long one. But the first study of flat-faced dogs meeting other dogs, with 30 dogs, found that they signaled as much as dogs with medium-length muzzles — while the other dogs responded to them differently, with more tongue flicks and fewer play bows.
What should I do when a strange dog comes toward my Frenchie?
Keep your distance, and do not wait for your dog to warn the other one — he may already be doing it in a way you cannot see. Turning and walking away calmly speaks for both of you. And watch the other dog’s tail, ears and body rather than your own dog’s face: they will tell you more.
References
- Goodwin D, Bradshaw JWS, Wickens SM (1997). Paedomorphosis affects agonistic visual signals of domestic dogs. Animal Behaviour 53(2):297–304. sciencedirect.com
- Leaver SDA, Reimchen TE (2008). Behavioural responses of Canis familiaris to different tail lengths of a remotely-controlled life-size dog replica. Behaviour 145:377–390. web.uvic.ca
- Siniscalchi M, Lusito R, Vallortigara G, Quaranta A (2013). Seeing left- or right-asymmetric tail wagging produces different emotional responses in dogs. Current Biology 23(22):2279–2282. pubmed.ncbi.nlm.nih.gov
- Eretóvá P, Liu Q, Přibylová L, Chaloupková H, Bakos V, Lenkei R, Pongrácz P (2024). Can my human read my flat face? The curious case of understanding the contextual cues of extremely brachycephalic dogs. Applied Animal Behaviour Science 270:106134. sciencedirect.com
- Canori C, Biffi E, Gaggia L, Iuliano B, Valsecchi P (2025). Do looks matter? Investigating facial expressions and intraspecific communication across different dog morphotypes. Applied Animal Behaviour Science 291:106720. sciencedirect.com
- O’Neill DG, Packer RMA, Francis P, Church DB, Brodbelt DC, Pegram C (2021). French Bulldogs differ to other dogs in the UK in propensity for many common disorders: a VetCompass study. Canine Medicine and Genetics 8:13. pmc.ncbi.nlm.nih.gov
- Whole Dog Journal — Eldredge DM, DVM. Dog Ear Signals. whole-dog-journal.com
