All language subtitles for How.Dogs.Got.Their.Shapes.2016

NARRATOR: There are nearly
1 billion dogs walking,
sniffing, and barking

all over the planet.

In exchange for free
meals, they've evolved
side-by-side with us

like no other species
in the animal kingdom.

MARTY: When you pet a dog,
after just a few seconds,

you get this surge
of oxytocin which
is the hug hormone.

And you get phenylethylamine
which is that active
ingredient in chocolate.

NARRATOR: Dogs are more than
our most loyal companions;

they're superheroes
of science.

With over 400 breeds and
countless variations,

man's best friend
has become the most
diverse mammal on land.

So the big question is, how?

.

Every dog, large and small,
evolved from just one species.

.

ADAM
So the ancestor of the
dog was the grey wolf.

And the grey wolf looks a
lot like other wild canids.

So it's got prick ears, it's
got long sharp incisors,
it's got a bushy tail.

NARRATOR: It's a necessary
build for surviving nature's
harshest conditions.

.

But 15 to 30,000 years ago,
humans' discarded scraps
transformed less aggressive

wolves from hunters
into scavengers.

ADAM: They no longer
had to have a shape
that was finely tuned

to bringing down large game.

NARRATOR: Physical changes
spawned something new:

Canis lupus familiaris,
better known as dogs.

They were the first
domesticated species on earth.

And their bond with
humans has changed both
their behavior and shape.

HEIDI: As time goes by we
keep selecting for smaller and
smaller dogs, and we get this

huge range of dogs that can
cover every job imaginable.

ADAM: People started breeding
dogs as hunting companions,

as fighting dogs, as companion
dogs, as herding dogs.

NARRATOR: The advent of kennel
clubs in England in 1873

put them on the
evolutionary fast track.

ADAM: That's when breed
standards were made,
and that's really

accelerated the diversification
of all the different,

shapes and sizes and behaviors
and forms of dogs today.

LINDA: We shape the dogs,
and how they ultimately
appear, by our choices.

NARRATOR: From noses to tails,
coats to paws, their shape has
changed their entire history.

Every part of a dog's body
has a tale to tell, from
the bottom to the top.

The canines' ancestors
have ears wired for sound.

Acute hearing is vital to
hunt down even the tiniest
rustle of prey from afar.

But modern dogs have
different priorities.

ADAM After
dogs became domesticated,
their ears diversified.

And they don't need to
hunt big game anymore.

They're scavenging for
people and whatever looks
cute and can give them

a good expression is what
their meal ticket was.

NARRATOR: Alternative
ear styles have
different benefits.

The button ear, on burrowing
dogs like the Jack Russell
terrier, folds over itself to

cover and protect the
ear canal from the dirt.

Newfoundlands are a
working water dog.

Their drop ears cover their
ear opening to prevent water
from entering the ear canal.

Rose-shaped ears are slicked
back and aerodynamic,

a requirement for any breed
with a need for speed,

like greyhounds.

There are many things
canine ears can do, but
number one is hearing.

Dogs hear four times as well
as humans, with a range of
frequencies twice as large.

Even the tiny ones hear better
than us, sometimes way better.

So when your house is
in danger, your best defense

may just be a mere
six inches tall.

It's hard to believe
Chihuahuas have
anything in common

with their grey wolf ancestor.

But actually, they have
at least two: their
prick shaped ears.

DEBBYE: It is a cone shape,
there's a lot of surface area,
and it concentrates the sound,

sends it straight
down to their eardrum.

NARRATOR: Chihuahuas likely
originated over 1,000 years
ago, and to this day,

their sense of hearing is one
of the best of any breed.

DEBBYE
Because Chihuahuas are
such a small breed,

it makes them vulnerable
to attack and to predators.

So their hearing
really is self-defense.

They can hear a threat coming
long before it gets to them,
gives them a chance to escape.

NARRATOR: 18 muscles power
gigantic ears that turn
like satellite receivers.

DEBBYE: You will literally
see one ear turn toward the
direction of the sound so that

they can pinpoint what
it is they're focusing
their attention on.

NARRATOR: When something
doesn't sound right,
they will let you know.

ADAM: Chihuahuas are your sort
of classic guard alert dog

and they will bark at
the first sign of danger.

DEBBYE: So they will
bark incessantly.

And that bark also protects
them, because if they can
alert their owner,

their pet parent, they know
they're gonna be safe.

MARTY: So these incredible
ears are just like
radar to pick up sound.

You don't need an alarm
system in your house if
you have a Chihuahua.

You will never have an
intruder, you will never
have a neighborhood dog

sneak through the yard, but
you'll probably never have a
total night's sleep either.

NARRATOR: Chihuahuas have some
of the best hearing around,

but which dogs
can't hear at all?

On their birthday,
all of them.

Puppies come out of the womb
without the sense of hearing.

MARTY: Their ear canals are
actually kind of swollen shut.

Usually it takes anywhere
from two to three weeks
before they can start to hear.

NARRATOR: Dogs have a
short gestation period,
just two months,

which means some body parts
need to mature after birth.

.

When a crime breaks out and
a fugitive is on the loose,

there's one member of the
task force who's all ears.

.

Bloodhounds sport
two of the longest
drop-ears of any breed,

with an average of eight
to ten inches each.

Surprisingly, the large
size doesn't aid in hearing.

In fact, it's
detrimental to it!

But the ears are prized
assets when it comes
to the job of tracking.

DEBBYE: Believe it or
not, their ears help
them with their smell.

NARRATOR: Here's the evidence...

Exhibit A: long droopy
ears block sounds from
entering the ear canal.

DEBBYE: These big long
drooped ears actually sort
of close off distractions

and allow them to
focus on the smell.

NARRATOR: Exhibit B:
their ears scratch
the trail's surface.

DEBBYE Those long
earsdragging along the ground
helps rustle up and disturb

the scent that's in
the ground to help them
track a specific scent.

NARRATOR: Exhibit C:
their ears help decipher
the evidence.

DEBBYE The shape
and theplacement of these long
droopyears can literally form a

cone around them, so when
they put their head down
it concentrates the smell

in the immediate area
where their snout is.

NARRATOR: Scents then get
wafted up towards the most
powerful doggy nose on earth.

DEBBYE: They have up to 300
million olfactory cells, the
nerves that help them smell,

which is 60 times the
olfactory cells that
a human being has.

MARTY You might
have somebody that had walked
through here 12 hours ago

that is multiple miles
away and they still
can smell their scent.

NARRATOR: So if someone
goes missing, you're
in good hands, or paws,

when a bloodhound and his big
droopy ears are on the case.

Canine quiz!

Which pooch currently
holds the record
for longest dog ears?

NARRATOR: Canine quiz!

Which pooch currently holds
the record for longest
ears on a living dog?

The longest canine ears
on the planet belong to
a coonhound named Harbor.

Coonhounds likely descended
from bloodhounds and foxhounds,

but Harbor's
record-breakers stand alone.

His left ear measures
12 and a quarter inches while
his right one is even longer:

an outstanding 13 and a half.

There's a unique shape behind
every canine, so what's the
backstory on their behinds?

When picturing our
four-legged friends,

a wagging appendage
comes to mind,

and it does a lot
more than thump.

DEBBYE: You actually can tell
a lot about a dog breed,

and what they are bred
to do, by their tail.

NARRATOR: The tail
is made up of six to 23
highly mobile vertebrae.

Originally long
and fluffy, its main
purpose was for balance.

But as the tail took on more
jobs, it evolved into a vast
array of shapes and sizes.

DEBBYE: There are long ones,
there are short stubby ones,

there are feathered ones,
there are curly-Q ones.

And all of them play
a role in the function
of that dog's breed.

NARRATOR: Genetic mutations
and behavior adaptations led
to a range of tail styles.

Humans breed for the
ones that perform best
at specific tasks.

Whippets have long, slender
tails that improve their
agility and help them make

turns while traveling
at high speeds.

Some Pembroke Welsh
corgis are born without
much of a tail at all.

A one gene switch
and they grow just a
bobtail on their behind.

Huskies use their tails
for temperature control.

DEBBYE: The tail on a Husky
is literally a big furry puff,
and the husky can curl up in

that subarctic weather
and cover his face and
keep his nose warm.

NARRATOR: And there's
one breed that owes
much of its well-being

to the very tip of its tail.

.

Raising a white flag normally
means you've given up.

But for this pup's
tail, it's a victory.

DEBBYE: Beagles date
back to the 1500s.

English hunters bred them to
be a companion, a partner to
the hunter out in the woods.

NARRATOR: They're bursting
with energy and speed,

possess a powerful sense of
smell, and have a low build

that's perfect for tracking
down rabbits and larger hare.

DEBBYE: Beagles literally
use their whole body to hunt
and they're even colored to

blend in with their
environment so the prey
doesn't see them coming.

LINDA: If they get on a scent,
they will chase it down and

they won't look up
for miles and miles,

sometimes going,
"Where am I?"

NARRATOR: There's
one big disadvantage to
these hunting machines.

They're so good
at camouflage that even
hunters lose track of them!

LINDA When you
have apack of dogs traveling
aheadof you in the distance,

with their noses down,
chasing a large rabbit,

you want to be able to
see where they're going.

NARRATOR: Losing your
pooch is a red flag, so
beagles raised a white one.

DEBBYE: Some of the dogs had a
white tip on their tail which
made it easier to spot the dog

and so breeders began to
breed for this white tip

so that hunters would
know where their dog was.

NARRATOR: This feature
is now the golden
standard for the breed,

ensuring that beagles
will complete the hunt
and come out on top.

ROBERT: While the tail
doesn't talk, its actions
speak louder than words.

NARRATOR: Pay close attention
to the position of your pup's
tail and you'll notice that

it's a unique
communication device.

ROBERT: A dog wagging its
tail more to the right means
that they're happy and a tail

wagging more to the left
means that a dog is agitated.

NARRATOR: But make sure
to look up and down, too.

A stiffly raised tail can
mean they're on high alert
and standing their ground,

or that they're very excited.

And a tail between the legs
means the pup is frightened.

One of the most popular
canines on land has a tail
specially crafted for sea.

Labs are the most
beloved breed in America.

ADAM: They're loyal,
they're affectionate,
they're trainable.

You know, they're cute.

MARTY: This dog is the
Wal-Mart greeter that
lives in your house.

They are happy all the time.

NARRATOR: Their story began
over 200 years ago in maritime
Canada, when fishermen looked

for a dog that could jump
into the frigid waters
to fetch fish and nets.

Newfoundlands worked, sort
of, but these massive dogs
retrieved more than just fish;

they'd come back seeping
with icy cold water.

By mixing various working
breeds, fishermen concocted
the lab's ancestor,

the St. John's water dog,
which went extinct
in the 20th century.

MARTY: The St. John water
dog was a specific breed,
and it had rugged bodies,

they go through a lot of heavy
surf, very strong swimmers.

NARRATOR: Like a modern
lab, St. John's had a lot of
qualities that help fishermen:

water-repellent coats, a soft
mouth perfect for retrieving,
and perhaps most importantly,

a sleek tail modeled after
one of the best swimmers
out there, otters.

LINDA Its
very wide base that comes
back and narrows to a tip,

which helped them to
steer in the water.

MARTY: That tail
acts like a rudder.

So they can turn very quickly.

NARRATOR: When a swimming
pooch turns his tail, the
current applied against it

makes his entire body turn.

And efficient maneuvering
makes fetching
fish a total breeze!

By the 1800's, hunters
started using the St.
John's water dog on land.

They mixed the dog with
various European breeds
and a super mutt was born,

now known as the pure-bred
Labrador retriever.

LINDA: Labrador retrievers
were quickly adopted by
many, many people because

it had so many desirable
characteristics.

NARRATOR: Land or sea,
their loyal demeanor,
and hard-working attitude

make labs ideal pets.

Just be careful of that
otter-tail indoors.

LINDA: It's extremely muscular
and you need to be very
careful with the dog in the

house because it will
clear a coffee table.

NARRATOR: Canine quiz!

Which pooch has
the longest tail?

And how long is it?

NARRATOR: Which pooch
has the longest tail?

And how long is it?

Finnegan, an Irish wolfhound
from Calgary, Canada

holds the canine record
for longest tail.

Bred large to hunt
wolves and Irish elks,

Irish wolfhounds are the
tallest breed there is,

and Finnegan's tail truly
stands above the rest.

It measures a
whopping 28.46 inches.

For thousands of years,
the size of dogs evolved to
match their environments.

At the same time,
humans have selected for
height, weight and shape.

From the tiny teacup Yorkie
to the gargantuan Great Dane,

canines now come in more sizes
than any other mammal on land.

ADAM: So the smallest
dogs and the largest dogs
are 100 times different

in how much they weigh.

And five times different
in how tall they are.

NARRATOR: It used to be that
all dogs could interbreed.

These days, massive
size discrepancy makes
mating much less likely.

HEIDI: Chihuahuas and Great
Danes, people would look at
those two breeds and think,

this actually has to be
a completely different
species at this point.

NARRATOR: Why do some breeds
stop at mere inches while
others grow into giants?

HEIDI: One of the really
wonderful things about dogs
is how they've been able to

adapt to all of our
different lifestyles.

ADAM So all
dogs big and small have the
same 39 pair of chromosomes.

But there's about a dozen
genes controlling body size
that really drive most of the

differences between
small dogs and big dogs.

NARRATOR: All dogs have
99.5% of their DNA in common,

which means that only half of
a percent difference in DNA

is responsible for one dog
becoming a Great Dane,

and another a Chihuahua.

ADAM: One of the most
important genes is called
"insulin growth factor one"

that explains about 40%
of the variation in body
size across modern breeds.

NARRATOR: Measuring just
six to nine inches tall,

Pekingese are so tiny
they can fit in a sleeve,

which is exactly where they
were placed in ancient China.

DEBBYE: Legend has it that
if someone attacked them
the dog could pop out and

surprise the intruder
and bite them.

NARRATOR: Dachshunds have
extraordinarily long torsos,
so their heads can go deep

into holes while
their back-half stays
safely above ground.

And for some dogs,
bigger is better.

Great Danes are one of the
tallest breeds in the world,
typically clocking in at a

whopping 28 inches or more
at the shoulders for females
and over 30 for males.

DEBBYE: Great Danes
are exactly what their
breed name calls them.

They are a great big dog.

They have huge skeletons,

they can stand as high
as seven feet tall if
up on their back legs.

Big heads, big muzzles and of
course those long lanky feet.

NARRATOR: Believed
to be a cross between

big English mastiffs and
mighty Irish wolfhounds,

Great Danes have
always been giants.

In medieval Germany, they
were bred to hunt wild boar.

LINDA: They would chase these
giant boar through the forest.

DEBBYE: They were
really a very ferocious,
very aggressive dog.

NARRATOR: But as hunters
bred them larger and
larger into the 1800's,

people took notice of
their eye-catching size,

and they became a
sort of canine celebrity.

LINDA: Landed gentry
started using them more
and more as estate dogs.

As impressive beasts that
would wander their estates and
they were kept in the homes

and often lived up on
the furniture, closely
alongside the humans.

NARRATOR: They were so
beloved, that in 1876 they
became the national dog of

Germany, which, over time,
had an interesting impact
on their temperament.

DEBBYE: They were no
longer bred to be fighters;
they became a pet.

NARRATOR: By breeding
only the friendliest
Great Danes together,

these guys lost
their aggression,
but not their stature.

DEBBYE And really
theyare gentle giants now.

They're just the world's
largest couch potato.

.

NARRATOR: While a
Great Dane can hardly
fit on our furniture,

the smaller "toy" breeds were
specifically engineered for it.

So when you see a tiny
toy breed sitting pretty
like it's their job,

know that in ancient
China, it actually was!

DEBBYE: Toy breeds
were developed purely
to be companions.

They were literally bred
to keep the emperor's
feet or hands warm.

NARRATOR: Sometimes it
takes a little dog to
complete a big task.

And few pups pack more
punch per pound than
this powerhouse pet.

This lovably stocky, low to
the ground, breed's distinct
shape helped them excel in a

rather crude sport in England
back in the 17th century.

MARTY: There used to be a
sport called bull baiting
where bulls were actually

chained up and then
dogs would attack them.

NARRATOR: While it sounds
cringe-worthy, animal
baiting had a purpose.

LINDA: Back then, the common
belief was that the meat got

tenderized by this
stressful experience.

So these bulldogs would
chase around these bulls

who would fight in the
community center there,

and attract all the
potential customers,

and they would then
get a premium price

for these stressed
animals' meat.

NARRATOR: The bulldog's
unique build is surprisingly

the perfect shape for
terrorizing a massive bull.

DEBBYE: And so they have
these short legs so that they
could literally get low to the

ground and even sneak under
the belly of the bull so the
bull couldn't see them coming.

NARRATOR: When a bull
looked down to see
what was bothering it,

it was in for an
unpleasant surprise.

DEBBYE: The old breeds used to
open their mouth wide enough
to get a big chunk of the

bull's snout, and
hold on for dear life.

NARRATOR: In 1835, the passing
of an animal cruelty act
put an end to bull baiting.

LINDA They lost
their function and consequently
a group of gentry who really

loved the bulldogs decided
to try to save them.

NARRATOR: And we selectively
bred these fighters
to become flat-faced pets.

MARTY They
started getting even more
exaggerated features.

Push the nose in,
push the nose in further,
push the nose in further.

Shorten the legs, so more
of that kind of stance
where big upper chest,

tiny little lower body,
big pushed-in face.

They could never fight today.

DEBBYE: The bulldog of
today can't fight anything,

might fight for your
spot on the couch,

or for their next dinner, but
that's about the extent of it.

NARRATOR: Canine quiz!

Can you name the tallest dog?
How tall is he?

NARRATOR: Can you
name the tallest dog?

An almighty Great Dane named
Zeus holds the Guinness
record for tallest dog.

This righteous pup measures a
whopping 44 inches tall from
his paws to his shoulders,

a whole foot more than
the average Great Dane!

There's a famous saying,
"It's not what you wear,
it's how you wear it."

And for a dog,
style is everything.

Canines wear some of the most
sensational coats on earth.

But the source of their
beauty comes from within.

HEIDI: We found out that there
are three main genes that
can be altered and create

six different types
of dog coats.

NARRATOR: From bristly
short to elegantly long,

the variation is
truly astonishing.

DEBBYE: The coat on
a dog is so much more
important than beauty.

The coat on the dog helps
them perform a function.

NARRATOR: Wiry coats, as
seen on border terriers,

work as a coarse
protective layer to
shield from the elements.

Originally native to
the cold and windy high
altitudes of Afghanistan,

Afghan hounds
have extravagant,
long-haired coats

that serve as tip-to-toe
temperature protection.

Komondors, originally
a herding breed, sport
dreadlock-like corded coats

to help them blend in with
sheep, and shield their bodies
from the bites of predators.

Poodles are famous for
a distinctively clipped,
some might say poofy, coat.

But it's not just for show.

DEBBYE: Those puffs on their
head and over their hips and
on their legs actually help

keep the joints warm.

ROBERT: The Dalmatian is
actually born white and
develops spots over time.

NARRATOR: Dalmatians' spots
serve no evolutionary purpose,
aside from looking awesome.

Then there's a breed
whose coat creases,
crinkles and wrinkles.

MARTY: When you think of
this breed, I think of
why they created Botox.

NARRATOR: But the wrinkles
on a shar-pei have nothing
to do with growing old.

LINDA: They have way
too much of a molecule
called hyaluronan,

which is a very gel-like
substance in the skin,

and they have a mutation
that makes them make as much

as ten times what
they should have.

HEIDI: The hyaluronan builds
up in the skin and creates

sort of space for
more skin to grow.

And that's where all
the folds come from.

NARRATOR: The original
shar-peis were not quite as
wrinkly as some seen today.

But their genetic mutation
has become drastically

more noticeable throughout
their 2,000-year history.

LINDA: People found the
wrinkles so cute and so
snuggly and so adorable,

breeders selected for dogs that
had more and more wrinkles

that were maintained
into adulthood.

NARRATOR: The wrinkles
aren't just for show;

ancient Chinese dog
fighters utilized them
as a built-in defense.

HEIDI If he had
been bitten, that excess skin
was supposed to give the dog the

ability to turn around and
still be able to get the
dog that had attacked him.

NARRATOR: It also means
opponents chomp on a
mouthful of wrinkles

instead of the meat underneath.

Fortunately, bigger and
badder dogs came along and

shar-peis were no
longer forced to fight.

But they couldn't
rest easy for long.

The Communist Party
opposed the ownership
of dogs in the 1950's.

And so many shar-peis were
slaughtered that by 1978,
there were only 60 left,

and they were declared the
rarest breed in the world.

Passionate shar-pei
enthusiasts ultimately
straightened out this breed's

population problem, but
the same can't be said
for their extra wrinkles.

As many as one in ten
humans are allergic to dogs.

Contrary to popular belief,
it's not always their
coat that causes reactions.

DEBBYE: People are allergic
to a specific protein
in the saliva of the dog.

So when a dog licks their coat
or their skin, they deposit
that saliva on their hair and

that's what makes
people sneeze.

NARRATOR: There's no such
thing as a completely
hypoallergenic dog.

But some pups, like
wheaten terriers,

have coats that naturally carry
fewer allergens than others.

So if you really want your
allergies to calm down,

wash off your pooch!

Dressing fashionably in
weather extremes is tough.

But one breed's coat
undeniably stays in style
throughout all four seasons.

The husky is a heroic breed
group we've been relying
on for over 1,000 years.

Ever since they lived as
nomads with the Chukchi tribe,
huskies have helped humans by

transporting food, medicine,
goods and even people.

And with just a glance, it's
easy to see they have a lot in
common with their ancestors.

ADAM: So Siberian huskies
are domesticated dogs that
have regained a lot of the

characteristics
that wolves had.

In fact, we think there
was probably a little bit
of wolf blood that got

added back in when they
were making the breed.

Like wolves, they've
got prick ears, they've
got a nice bushy tail.

NARRATOR: And one more, hairy
thing, a thick double coat.

To sled in frigid temperatures
of negative 75 degrees,

yet avoid a meltdown
when the mercury rises,

the husky coat has a
few tricks up its sleeve.

Their two layer coat
changes with the weather.

In the winter, an
inner layer insulates
by trapping in body heat,

and an outside
protective layer

keeps the frigid cold
air even further away.

But in summer, it's a
whole new ball game.

Huskies go through a process
called "blowing coat,"

which is another way
of saying they shed.

And shed.

And shed some more, until
their winter coat is
left blowing in the wind.

Yet holding onto
their outer-coat actually
helps them beat the heat.

DEBBYE: The outside
protects them from
the UV rays of the sun

so they don't get sunburned.

NARRATOR: As long they stay
in temperatures below 65,

huskies will keep their
cool while working hard,

delivering whatever we
need, whenever we need it.

In addition to sledding,
huskies make great service
dogs and family pets.

And just know, that they
tend to get attached.

MARTY: If you want to
wear your pet to work
I suggest getting one.

NARRATOR: Canine quiz!

We've learned that huskies
have two coats, but can
you name any bald breeds?

NARRATOR: Canine quiz!

There are a few
canines whose only suit
is their birthday one.

Can you name any bald breeds?

This distinction goes
to the Chinese crested
and Mexican hairless.

In ancient times, the body
heat radiating off a hairless
dog's bare body

was used to aid ailments like
headaches and stomach aches

by placing these breeds
directly on aching joints.

From digging buried bones to
chasing just about everything,

it's the particular
shapes of these four parts
that put pooches in motion.

The specific shape and build
of a canine's quarters impacts
their abilities and skills.

HEIDI Short legs
in dogs are good for digging.

But the long legs are
especially good for running.

And this doesn't always go
along with their body size.

For instance, a basset hound
is actually a very large
dog with very short legs.

NARRATOR: For this breed,
coming up short pays off big,

a low build gets their
nose closer to the ground

to help them track
scents with greater ease.

A gene-mutation
prevents their legs from
reaching full heights,

and corgis have it, too.

DEBBYE: They were built to
nip at the heels of cattle

and that's how they
helped herd them.

HEIDI: When the cow tries to
kick back at the herding dog,
he usually misses the corgi

because he's
underneath the kick.

NARRATOR: And then there's
deep diversity in doggie paws.

MARTY: Well there's a lot of
difference in paws for dogs.

Like some dogs in the
northern climates,

they have to have stuff
that has very good traction.

NARRATOR: When climbing
up an icy hill,

large broad pads help grip
and clutch the ground.

Webbed paws on a Labrador
retriever help them swim.

But perhaps no dog does
more with what little he's
got than this lengthy hound.

Call 'em what you want: hot
dogs, wiener dogs, weenie
dogs, or frankfurters.

This little legged breed
does have an official name.

Dachshunds can't shake off
the distinction of having

teeny tiny legs paired
with a long body.

MARTY: I like to call
'em two dogs long and
a half a dog tall.

NARRATOR: But there's a method
to the evolutionary madness.

HEIDI: So the bone deformity
in short-legged dog, it's
really a form of dwarfism.

Oftentimes the legs are
a little bit bowed and
that's basically because

they stop growing in
length early on.

NARRATOR: Developed
in medieval Germany over the
course of hundreds of years,

dachshunds' tiny legs
make them one of the best
burrowing breeds around.

MARTY There's
several advantages of dachshunds
having these really short legs.

They're really low to
the ground, so they're
really good trackers.

NARRATOR: And when
they find their prey,
they don't let go,

even when they're underground.

HEIDI It's very
easy for them to dive into the
holes of badgers or rabbits,

for hunting purposes, to get
in there, you know, attack
the prey and pull it back out.

NARRATOR: Their tiny legs
allow them to fearlessly
explore narrow holes without

getting stuck,
and they go deep.

MARTY: It's a dog that might
have its, its nose in one zip
code and its tail in another.

NARRATOR: Just keep track
of where they wind up.

HEIDI: Dachshunds are also
excellent at hanging out
underneath counters in the

kitchen and picking
up scraps without anybody
noticing that they're there.

NARRATOR: Dogs walk on
their toes, while humans
walk on their heels,

but there is something
we both have in common:

a love of pampering.

A paw massage puts pups at
ease while also promoting
better circulation.

If their pads are cracked or
dry, ask a veterinarian for
special doggy moisturizer

to help soothe them out.

Zipping around at speeds
of 65 miles per hour,

cheetahs are the
fastest animal on land.

But there's a dog
not too far behind.

Portrayed on cave art,
and dating back to as
early as 8000 B.C.,

greyhounds are one of the most
ancient breeds in the world

and they haven't slowed
down as the years piled up.

Greyhounds aren't just
the fastest breed;

they're one of the
fastest species on earth.

LINDA: They are truly the
most specialized running
dog we have created.

In six strides they can
get to 43 miles per hour.

NARRATOR: They're the
most prized breed for
hunting speedy prey

like deer, foxes, and hare.

And they've covered
a lot of ground,

greyhounds can be
traced to nearly every
continent in the world.

Every inch of their
body is built for speed.

DEBBYE
Greyhounds are sort of the
super model of the dog breeds,

because they
have no body fat.

So you can see every strong
muscle through their skin.

They are literally
the sleek, aerodynamic,
narrow bullet of a dog.

NARRATOR: And when
they hit the ground
running, they go hard.

DEBBYE: They have a webbed
foot which allows them to
really pound the ground when

they make a strike.

And then they have these
really thick pads to take
that amount of impact.

NARRATOR: But that's
not the only thing that
helps the legs go fast.

DEBBYE: The way
a greyhound runs, they
literally go airborne.

NARRATOR: Because even their
spine is built for cruising.

DEBBYE: They have these
long spindly vertebrae,

and they are articulated
or joined together in a way

that they can stretch
them slightly open so
they can get the

maximum amount of reach and
literally fly through the air.

NARRATOR: Their spine enables
a unique running method

known as the
double-suspension gallop,

making them go airborne
twice per run cycle.

Once when their back
legs kick off the ground

and again when their
front legs make the leap.

The only downside
to their anatomy is when
they shut off their motor.

LINDA: Greyhounds really
can't sit properly because

they can't get those pelvic
bones down to the ground,

so you'll see them in kind
of awkward gawky states

when they're trying to sit.

NARRATOR: Fortunately,
when you're this fast,

you don't have to
excel at sitting.

Canine quiz!

There are four distinct
claws on a pooch's paw,

but what's the name
of the obscured fifth
one off to the side?

NARRATOR: Canine quiz!

Dogs have four distinct
claws on their paw,

but what's the name of the
fifth one off to the side?

The mini-digit on the
inside of a pooches' front
leg is called the dewclaw.

Similar to a human thumb,
it helps some dogs grip and
hold onto to precious items.

While every dog is
delightfully different,

there's one particular
part that varies the most.

MARTY: Their head is like
somebody had a lot of fun.

There's the pug that
looked like it ran 60
miles an hour into a wall.

And then there's the ones
where their nose and the
back of their head

are in two different zip codes.

NARRATOR: The facial
region of every dog
consists of 36 bones,

but its specific
shape determines

which job a breed
is best suited for.

HEIDI: There are three
basic head types in the dog.

What we call brachycephalic,
or short faced.

And that is what you see
in pugs and bulldogs.

There's mesocephalic,
which is mid-sized face.

And that's sort of
your standard Labrador
retriever or pointing dog.

And then you have
dolichocephalic, which
is a very long face.

And that's what you would
see in sighthounds like
a greyhound or a borzoi.

NARRATOR: Flat-faced
breeds, like boxers
look absolutely adorable,

but the compact build
comes with a price:

there's less space in their
muzzle to circulate air,

which makes them
prone to overheating.

Salukis elongated snouts and
eye sockets set farther back

are great for spotting
small prey in the distance.

MARTY: So it's almost like a
gun sight with two little long
binoculars looking down there.

NARRATOR: And some canines'
heads help us spot prey.

The appropriately
named "pointer" uses his
noggin to alert hunters.

MARTY: So the game's creeping,
the pointer's creeping
and finally they both stop.

And they're just
staring at each other.

So for the hunter,
they can tell by the
direction of the head

exactly where the game is.

NARRATOR: But when it comes
to being level-headed,
one dog has them all beat.

Looking one part egg and
one part alien, the bull
terrier's odd shaped head

is one of the most
unique-looking on the planet.

MARTY: Talk about a
distinctive look, there's no
other skull looks like it.

NARRATOR: Even their
triangular-eyes
differentiate them

from the rest of the breeds.

But the shape of their
heads didn't always
make us scratch ours.

ROBERT: The bull terrier is
known for its egg-shaped head

but it didn't always
look that way.

NARRATOR: Its original
appearance was better
suited for being a bad egg.

ROBERT: The bull terrier
was originally bred
in England in the 1830s.

It was designed to be
the ultimate fighting dog

by crossing the tenacity
of a terrier with the
brute force of a bulldog.

NARRATOR: A new breed called
a "bull and terrier" was born.

With ferocious energy and
enough muscle to back it up,

they were a sight
to see in the ring.

Not long after the bull
and terriers' creation,
dog fighting was outlawed

and this super-dog was
left without a function.

So the purpose of this pooch
became to make us smile.

We selectively bred their snout
to become more pronounced,

until it nearly took
over their entire face.

MARTY: It's just like their
whole head is their nose.

NARRATOR: The bull terrier
became the dog that makes
you do a double take.

Dogs often tilt their heads
to the side when we speak.

It turns out it might not
just be to hear us better.

One theory suggests that the
change in perspective helps
them see our entire expression

without their muzzles
blocking the view.

It's also entirely possible
that they're just being cute.

You've probably heard that a
bark can be worse than a bite.

But for one breed, their
bite is as bad as it gets.

Rottweilers have a bad
rap for being brutal.

The issue stems
from their heads.

ROBERT: Rottweilers have
massive skulls which house

some of the strongest
jaw muscles around.

NARRATOR: Their bite
isn't quite as powerful
as a great white's.

But the Rotty's 300-pound bite
force is nothing to scoff at.

DEBBYE: Once they bite
down it's almost impossible
to force them to let go.

NARRATOR: So how was this big
head used to their advantage?

ROBERT: A Rottweiler's
heritage can actually be

traced back to the Roman Empire.

When Rome was busy conquering
Europe, they brought their
cattle driving dogs with them.

NARRATOR: Their natural
strength was a good fit

for moving cattle
over long distances,

and their intimidating bite
not only ensured cattle
wouldn't get stolen,

but that even small valuables
were safe and sound.

ROBERT: Their owners would
actually hide money in the
collars because no thief

would think to ever
put their hand there.

NARRATOR: But when the
Industrial Revolution
came around,

we began moving cattle by rail

and Rotties, and their
big heads, were out of a job.

LINDA: But there were
so many people who
truly loved these dogs

that started looking
for new jobs for them.

NARRATOR: Luckily, there
was employment for a
dog with a menacing mug.

LINDA And they
became developed as guard dogs,

they had important
roles in the military,

and they continued
to have a function

which allowed the breed
to be perpetuated.

NARRATOR: Despite their
intimidating demeanor, they
do make a great family pet.

Because deep down inside,
if you train them right,

most Rotties are just
big-headed goofballs.

Dogs have undergone an
overwhelming amount of
change throughout history,

and there are no signs that
their rate of evolution will
slow down anytime soon.

ADAM: It's safe to say anywhere
humans are gonna go, they're
gonna take dogs with them.

NARRATOR: As our lifestyles
and needs evolve, so too,
will the shapes of canines.

HEIDI: There will be more breeds
because our lives change,

and then we create sort
of a slightly new dog

that's gonna fit
into our new life.

NARRATOR: Any shape or any size,

they will forever be
man's best friend.

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