There is a rumor that you can breed dogs in Nintendogs. Please note that this DOES NOT work in Nintendogs + Cats. According to the rumor you must have 2 dogs of the same breed, one male, one female. They must be bought on the same day. Color doesn't matter. The female dog must wear a rose and the male dog a lucky collar. Then you must get the dogs to bond. This can be done by letting them play together and cuddle together. The toy must be one they BOTH like, not just one of the dogs. You can even put music on for breeding if you want. You have to feed the dogs only milk and dry food or natural dog food. Do this routine for about 4 days or until the female dog gets fat. When you brush her, you should see kicking. Do not bathe the dogs at all if they are dirty. Only brush to check for kicking. Do not take walks or enter into competitions at all. After that, wait. You will not be warned when the female is pregnant or when she has the puppy. If you're lucky you'll only have to wait approximately 4 days before the puppy is born. The dogs don't have to wear the rose and lucky collar, but they increase chances of breeding. Please note that this is merely a rumor and that it may or may not be true. Some people say you can walk the dogs, but only the male can go for walks/competitions. There are different variations to this guide. Some people use Action Replay to hack a new dog into the game, but THIS IS NOT RECOMMENDED, AS IT CAN POTENTIALLY BREAK THE GAME!