@Background Pony  
Thankfully he isn’t though. The only time he’s a pet is in Equestria girls, and he’s only like that for plot-convenience (once spike the dog talks, twilight has her evidence to prove she’s from another world).
 
He isn’t walked on a leash, in the secret of my excess she takes him to a pony doctor first and ONLY takes him to the vet, when the doctor recommends it (and even when he does, look at her face, she’s devastated by that remark). Plus in “Just for Sidekicks” they let him pet-sit. If he was a pet, they would let him watch other pets. That’s like letting your infant, babysit other babies. And for that matter, all the other pets don’t have the ability to speak, but he does.

I always thought Spike was Twi’s pet anyway.

Every pony is going to want their own dragon now.