seven dog years."

Myth. Myth. We could cut it right there.

Carly Fox: "Certain dog breeds are hypoallergenic

because of their fur."

This is a major, major myth.

"Only male dogs hump."

Hi, I'm Dr. Ann Hohenhaus, I'm the staff veterinarian

at the Animal Medical Center

here in New York City.

My name is Dr. Carly Fox, and I'm an emergency

and critical care staff veterinarian

at the Animal Medical Center.

Hohenhaus: Today we're debunking dog myths.

Fox: I think, honestly,

the majority of male dogs

do like to hump, but I guess female dogs

also can be seen to exhibit that behavior.

Hohenhaus: But males hump more than females.

Fox: Definitely, yeah. But, I mean,

I guess female dogs can also hump,

I mean, if they're in the mood.

Hohenhaus: Next myth: "Dogs are colorblind."

Dogs are partially colorblind.

People used to think they were totally colorblind.

Dogs have a little bit of ability to see color,

and so they see things

in kind of blue, yellow, and gray.

But they don't see a lot of color.

Fox: "Dogs don't like to be hugged."

I mean, biggest myth.

Physical touch is one of the things that

makes a dog a dog, so I can't imagine

that dogs don't like to be hugged.

I mean, dogs will literally climb onto your laps

in order to be hugged, so this is an absolute myth.

You can't and shouldn't just

go up to any dog and hug it.

Dogs still are different, just like people are.

Some people are huggers, some people are not.

So some dogs don't love that very direct attention

from someone perhaps they don't know,

so be sure to ask the owner

if you can pet or hug their dog,

and read the dog's signs.

Hohenhaus: Next myth: "One human year

equals seven dog years."

Myth. Myth. We could cut it right there,

but there's some really interesting research

behind this question.

So, the seven years probably comes

when people lived to be about 70

and dogs lived to be about 10,

so 70 divided by 10 is seven.

That's where that number maybe comes from.

Nobody knows, it's a myth,

so there's no data behind it.

Then, a number of years ago,

a group of researchers at Purdue University

looked at developing a formula for dog age

based on the size of the dog

and the dog's chronologic age,

or how many calendar years it was old.

And that formula might actually be the best.

This is a myth, but there are ways

that you can calculate your dog's age

based on a complicated mathematical formula.

Next one. Fox: Oh, OK.

"You should shave fluffy dogs in the summer."

This is mostly a myth.

A lot of people will shave their dogs in the summer

because they think it will make them cooler.

That's not necessarily true.

Dogs have adapted to all types of weather,

and they actually will shed

different coats at different times of the year

in order to sort of be

comfortable in that weather.

Hohenhaus: I think they don't like to be shaved

because they feel naked.

Fox: Yeah, probably. I mean,

why wouldn't they? They have no idea.

Hohenhaus: Yeah, they've never not had hair before.

So I'm not sure that shaving them

is always a good thing either, so myth.

"Dog saliva can heal wounds."

When's the last time you got bitten by a dog?

Fox: Probably, like, last year.

Hohenhaus: And it's ugly.

It is not healing wounds; it's making wounds worse.

This is a total, total myth.

Dog bites are really nothing to laugh about,

and most veterinarians get bit on the hand,

and so we're always worried

because we work with our hands,

so any dog bite needs to see a veterinarian

because it's a potentially infected injury,

and you need to go to your physician

to have that bite looked at.

Fox: "Certain dog breeds are hypoallergenic

because of their fur."

This is a major, major myth.

So, all dogs produce allergens,

and some dogs will produce

more allergens than others.

Dogs that don't shed, like poodles,

or smaller dogs that shed less

are less likely to produce a large amount of allergen

that can cause allergies in the environment,

and it really has to do with how often they shed

or if they shed at all.

But definitely all dogs produce allergens,

and all dogs could be allergenic,

but some dogs will produce less.

Hohenhaus: And now we have a different myth:

"You can't teach an old dog new tricks."

I think that's an idiom rather than a myth, isn't it?

Some famous saying.

I think that that is a myth.

Training a dog is never easy,

and it involves repetition

and persistence and rewards

in order to successfully train a dog,

but I don't think age is the problem.

I think we're more of the problem

in not sticking with training a dog.

Fox: Yes, they actually did a study about this,

and they did the same teaching of a trick

to young dogs and old dogs,

dogs that were six months to a year

and then dogs that were 10 years old.

And they actually found out

that both sets of dogs can learn a new trick.

However, the dogs that were older,

it took them twice as long to learn it.

So they can learn it, it's just something

that requires more time,

and that's definitely something that

you are going to have to commit to.

But it's possible,

and they definitely can learn new tricks.

Hohenhaus: "Dogs feel guilt."

I think that humans want the dog to feel guilt

for making a mess, chewing the furniture,

taking the fringe off the sofa,

destroying the pillows,

'cause we want them to be like us.

So, I don't think dogs

necessarily can really feel guilt,

but since they're not talking,

it's really hard to know if that's true or not.

Fox: Our dogs will display guilt-like behavior

when they do something wrong,

like, they'll put their ears back, they'll hide,

they'll look very guilty.

But I think in most cases,

that's really a reaction to you

and your tone of voice

or your anger at them

and your body language

rather than true guilt.

Hohenhaus: One of the reasons

that dogs have been

so effective in integrating

themselves into our lives,

the lives of humans for millennia,

is because they are very good

at picking up on social cues.

Fox: "When dogs wag their tails,

it means they're happy."

I would say in a lot of times

when dogs wag their tails,

it seems like they are very happy.

However, tail wagging is a behavior in dogs

that can mean many different things,

not necessarily happiness.

Hohenhaus: And I think the wag matters.

So you've got a dog whose tail is quivering like this,

that is not a happy wag.

Think about the Labrador, swish, swish, swish, swish,

they're pretty much always happy.

And then there's the dog who their tail quivers

and then it curls under.

That's not a happy wag either.

That's a "I'm really upset" wag.

So in addition to looking at the ears

and the eyes and the body posture,

ask yourself, what kind of wag is this dog doing?

Because that's gonna give you an indication

on the mood of the beast.

Fox: "Human food is bad for dogs."

Well, there are very particular

types of human food

that are definitively bad for dogs.

For example, chocolate is obviously bad for dogs.

Grapes, raisins are toxic to dogs.

Onions, garlic, those things are bad for dogs.

However, human food in general

is not necessarily bad for dogs.

We do wanna always limit the quantity

of human food for dogs.

I usually tell people less than 10% of their diet

should be human food.

Just human food in moderation

is not bad for dogs.

Hohenhaus: Well, dog food is

good balanced meal for a dog.

I interpret it to mean, should I cook for my dog?

And that is a bad idea because what we eat

is not a balanced diet for a dog.

And so home-cooked diets run a huge risk

of being deficient in nutrients

that are critical for your dog,

mostly deficient in calcium phosphorus.

So cooking for your dog, unless you've had a diet

made by a board-certified veterinary nutritionist,

is a bad idea.

"Dog mouths are cleaner than human mouths."

No. Human bites are

supposedly worse,

although we don't see a lot of human bites

at the Animal Medical Center.

But all of us have been bitten by a dog,

and we know that those

can get really badly infected.

What I've read is that if a

human bites another human,

it's awful, it's a terrible infection that you get.

So, no, I don't know that either is better.

Fox: Dog mouths and human mouths

are actually,

it's interesting,

they're sort of similar.

Both humans and dogs have over 200 types

of bacteria in their mouth.

However, because

disease is not really transmissible

between dogs and humans,

or there's not that much zoonotic potential

between dog saliva and human saliva,

they're clean in that, you know,

making out with your dog,

you won't contract the common cold,

but making out with a person, perhaps you can.

So, in that case, they sort of are cleaner.

However, they still have tons and tons of bacteria,

just like people mouths do.

Hohenhaus: "Dogs are afraid of their reflection."

This is...just no.

Just Google "puppies in mirrors,"

and you'll see that dogs love,

they're so enamored of that other dog

that they never met before.

They're really cute.

"Dogs can't digest grains."

So, this is a major, major myth.

Dogs can absolutely digest grains.

And not only can they digest grains,

but recent research shows

that they need grain in their diet.

Dogs on a grain-free diet are predisposed to

developing a very serious type of heart disease

called DCM, or dilated cardiomyopathy.

And dogs that are on a grain-inclusive diet

are not as likely to develop this heart disease.