Breed does not really matter as far as gameplay is concerned, although it does ensure you get the product you'd expect when breeding dogs. You'd have to desire a pretty rare dog to find it unavailable. Most popular dog breeds are offered in the game.

It only works for cats, dogs, and horses. I have not found a way to get someone to give away their dog without cheats, but know that using testingcheatsenabled true and shift-clicking a pet will allow you to move it to your active household. If it has a last name, it likely belongs to another family. Sims can easily befriend and adopt a dog from the streets, if you can find one. Of course, you can also come across strays. The selection of pets will change a little each day, as pets find a home. You can see the home offering a pet on your map, indicated by an orange marker. Sims who are giving them away will also put an advertisement in the newspaper. Dogs can be adopted by Sims using the computer or cell phone. You can then choose a dog breed to get started, or make your own custom dog. This allows you to make an adult male or female.

The most obvious choice for getting a dog is to make one in create-a-sim when creating a household. This guide will teach you about dogs, how you can find one, and train it to be a well-mannered and helpful pet. Sims can at last have a canine companion around the home with The Sims 3 Pets expansion pack. The Sims 3 Pets: Dogs Guide Canine Companions: Hunting and Training The Sims 3 Pets Guide

Sims 2 custom pet breeds