Popular (but Harmful!) Myths About Dogs

Odds are, if you're surfing the web to find out what kind of pup you should adopt next, you've run into a lot of misinformation. Find out which four dog myths you should never believe from an expert dog trainer.

Jolanta Benal, CPDT-KA, CBCC-KA
6-minute read
Episode #63

A couple of weeks ago I asked my Facebook fans to list their favorite dog myths. Boy, did people have a lot to say! You can’t teach hounds to come when called. A female dog needs to have a litter before she’s spayed. The taste of blood will make your dog aggressive. Golden Retrievers are always great with kids. 

Look: doggy folklore is everywhere. A lot of it is fairly harmless, but some do real damage to dogs and people alike. This week, I’ll unpack some juicy examples, harmless and otherwise.

Myth 1: Dogs are colorblind

You’ll often hear it said that dogs are colorblind. It’s not so surprising that this idea’s still around, because apparently dogs weren’t conclusively shown to have any color vision till 1989 (1). The researchers in that study tested only three dogs but got the right answer, which is that dogs have so-called dichromatic vision. They can distinguish blue from yellow but not red from green. Incidentally, they also perceive objects in motion much more clearly than they do objects at rest. That explains why that red rubber ball blatantly lying there on the Chem Lawn-green grass, absolutely shrieking “Notice me!,” is more or less invisible to your dog. Give him a minute, and he’ll find it with his nose.

Myth 2: Female pups need to have a litter before they’re spayed

Another fine item of health-related folk wisdom (cough) is that female dogs need to have a litter before they’re spayed. I couldn’t even imagine what the rationale for this might be, so I asked around.

Apparently the most common idea is that having a litter settles the female down and matures her. Basically, it helps her become a responsible dog. Well, a female’s first heat usually comes when she’s between 6 and 16 months old. Suppose she’s bred a bit later than that, she will probably be maturing socially right around the time she has a litter. But just because two things happen close in time doesn’t mean that one causes the other.

I promise, your girl dog will become a woman dog whether she has puppies or not.

And I look forward to the day when I meet a responsible dog of either sex or any age.

Myth 3: All dogs are good mothers

Also, if you’re having any soft-focus thoughts about how nice it’ll be for your human kids to witness the miracle of birth and motherhood, please remember that sometimes female dogs kill and eat newborn pups. Breeders speculate that this occurs mostly with puppies who are sick or otherwise unhealthy. Some mother dogs seem simply careless and will step on their newborns or smother them by lying down on them (2). If you still want to showcase the joys of motherhood, you can do it without contributing to pet overpopulation. Foster a mother dog and litter from your local shelter instead.

Myth 4: Pit bulls have locking jaws

The myth that pit bulls have locking jaws probably arose because pit bulls jaws are just plain strong. I have a video of my late, much-missed pit mix, Muggsy Malone, as he hangs by his jaws from a rope that two people swing back and forth. Come to think of it, don’t some human circus acrobats perform essentially the same trick?

The myth that Pit Bulls have locking jaws probably arose because pit bull jaws are just plain strong.

Informational sites about pit bulls all seem to cite the same expert, I. Lehr Brisbin from the University of Georgia, so I emailed him directly to ask about his research. Professor Brisbin wrote back: “Sorry, but this issue is so ludicrous that it defies logical refutation. If the pit bull jaw ‘locked’ on closing, how would they ever reopen it later to eat or drink?”

Hey, good question! Not content with mere logic, though, Professor Brisbin told me that he had participated in research on pit bull jaws from the collection of the Smithsonian Institution and “found no evidence of any locking mechanism.” (3). 

Other myths about pit bulls

With that cleared up, a few words about pit bulls in general. Pits are dogs. They’re strong dogs, but they’re not the only strong dogs. They’re athletic, energetic dogs, but they’re not the only athletic, energetic dogs. They can do a lot of damage when they aggress, and they always seem to get a lot of publicity for it, but I owe the scars on my right arm to an English springer spaniel, and it was a neighbor’s golden retriever who killed the terrier mix down the block from me.


Reliable statistics on dog bites and dog attacks are hard to come by, for complicated reasons (4). Reporting is inconsistent, and breed identifications are often shaky. How shaky? I was taking a walk one day when a man warned me about the pit bull sleeping under the park bench I was about to pass. Now, I knew this dog. For a pit bull, he looked an awful lot like a black German shepherd or shepherd mix. My dog Izzy, who precisely resembled a dingo, was once accused of being a pit. I wouldn’t have believed this was possible if it hadn’t happened to me.

Pits are still being bred to fight other dogs and probably they are more likely than your average dog to aggress against animals (5). But it’s worth recalling how many dogs Michael Vick killed for being unsatisfactory fighters, too.

Why dog myths can be harmful

You can spend your dog’s entire life thinking she’s colorblind and odds are the misinformation will never do either of you any harm. But many dog myths are hurtful or dangerous, so how do you evaluate what you hear? Sometimes you can bring down a myth with common sense, like Professor Brisbin asking that blindingly obvious question about how a locking jaw would unlock again.

Sweeping generalizations? Watch out. Third-hand reports? Forget them. There’s a reason hearsay isn’t admissible in court.

Next, look for evidence. It’s true that on the Internet anybody can (and does) say anything, but when a statement’s made over and over again without any scientific or statistical references to back it up, be suspicious. Sweeping generalizations? Watch out. Third-hand reports? Forget them. There’s a reason hearsay isn’t admissible in court.

As for experts, legally speaking, your 12-year-old can hang out her shingle as a dog behaviorist tomorrow, so that’s how much labels are worth. Ask about the qualifications of anyone offering information or advice.

There’s no licensing or formal education requirement, but conscientious dog trainers and behavior counselors read scientific texts and attend specialized seminars.


  1. Neitz, Jay, Geist, Timothy, and Gerald H. Jacobs. 1989. Color vision in the dog. Visual Neuroscience 3, 119-125; https://www.extension.org/pages/Through_the_Eyes_of_Your_Canine; and Alexandra Horowitz, Inside of a Dog: What Dogs See, Smell, and Know (Scribner, 2009), pp. 128-29.

  2. See, for instance, the discussion here – which, by the way, gives a good clear picture of how much work it is to raise a litter. The question of when is the best time to spay/neuter a dog is controversial, but although some vets advocate waiting until after growth is completed, no one believes that dogs have any physical or emotional need to actually become parents.

  3. I Lehr Brisbin, personal communication, May 16, 2010. The study is Bridgers, J. M., and I. L. Brisbin, Jr. 1989. Mechanical advantage in the pit bull jaw. Bulletin of the South Carolina Academy of Science LI, p.  51.

  4. For a thorough, well-researched, and entertaining discussion, see Janis Bradley, Dogs Bite: But Balloons and Slippers Are More Dangerous (James & Kenneth, 2005).

  5. See Duffy, Deborah L., Yuying Hsu, and James A. Serpell. 2008. Breed differences in canine aggression. Applied Animal Behaviour Science 114(3) (Dec.), pp. 441-60. This study, which sampled 33 breeds and is one of the few to include Pits, found “relatively average” stranger-directed aggression among them, but slightly more than a fifth of the Pits behaved aggressively (“snaps, bites, or attempts to bite”) toward strange dogs. Akitas showed a higher incidence of dog-dog aggression, Jack Russells missed by a hairsbreadth, and Aussie Shepherds and Dachshunds came close. Owner-directed aggression was lower among the sample of Pits than among the samples of (for example) Beagles, American Cocker Spaniels, and Shetland Sheepdogs. I don’t mean to single any of these breeds out except as examples of common family pets, and obviously the more powerful the dog the more potentially dangerous a given degree of aggression is. But the ticking-time-bomb Pit Bull is a myth.

About the Author

Jolanta Benal, CPDT-KA, CBCC-KA
