I don't own any dogs
If you want a big dog, it is better to start out when they are pups.
And don't abuse them, especially Rottweilers, Pit bulls, or Dobermen. They will return the abuse, and it will not be pretty.

Medium sized dogs and small dogs are good for apartments or small houses with little space and/or a small backyard.

Toy dogs(Chiuahuah or however its spelled, Pomerians)
Are good to keep in apartments, but they still are alot of work. Also, keep them from big dogs, because their ego is 10x bigger than they are. They can go alot of places big dogs can't, but their is a loss of protection.
I, myself, prefer large dogs, preferrably the Doberman, but also, you can't base decisions on what you prefer(sort of) you need to consider that they do need some space, and they need responsibility.
I have lots of expierience with dogs, though I never owned any. But there have been many at my grandparents' house in The Dominican Republic, so thats where I usually get what I know.
My friend in my building has a cocker spaniel which is a smaller dog but not a toy dog. It gets aggressive and the mofucker is small. Oh and if you don't want alot of pups, let it run around humping whatever(opposite or same sex) and then get it neutered, because that stregth comes from when they wanna fuck. And they'll fuck anything.

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