How do you say that your dog isn't any particular breed? The word you want is mongrel.

Hi Claudia, The correct way to ask the question is this: "How do you say" or "What is it called when your puppy is not an authentic dog breed?" (The second one is better.) There are two answers to this question. The more polite way to describe this is to say "mixed-breed." Eg. "My dog is mixed breed." You will usually say this if you are polite, or if you like the dog. The less polite way is "mutt." You tend to say this if you don't like the dog very much, or if you love it but want to insult it in a cute way. So about a dog you don't like you might say "Our neighbour's mutt won't stop pooping on our lawn." But if you do like it you might say "Come here you lazy mutt." (Then you can scratch it behind the ears or do something else that makes it happy!)

And the opposite to a mongrel is a pedigree.

mongrel