My friend
doesn’t have a dog.
My friend
hasn’t got a dog.
There are
no dogs in my friend’s possession.
My friend’s
dog is non-existent.
My friend
doesn’t have any pets, dogs included.
A statement that my friend has got a dog is simply untrue.
My friend has been dreaming about having his own dog since he was a little kid. Don't give up, Frank! A day will come.
My friend had been begging his parents to buy him his first dog for months, and guess what: they bought him a book!
My friend does have a dog, but, unfortunately, only an imaginary one.