Collie + Lhasa Apso = Collapso, a dog that folds up for easy transport

 Pekingese + Lhasa Apso = Peekasso, an abstract dog

  Labrador + Curly Coated Retriever = Lab Coat Retriever, the choice of research scientists

   Terrier + Bulldog = Terribull, a dog that makes awful mistakes

    Bull Terrier + Shih Tzu = Bullsh... Oh, never mind