Who Says Only Dogs Can Be Man's Best Friend?

Who said that only a dog could be my best friend?

I have a best friend,

but it's not a dog,

it's not a cat,

my best friend is....

13hh,

has four legs,

has hair,

eats hay,

grain,

loves to be pet,

loves to run,

and loves to be ridden,

Do you know what my best friend is?

My best friend was a...

Pony!