Some breeds practically train themselves, while others may continue to do their business inside well into adulthood. Here are the 10 breeds of dog that are most difficult to house train.

But with 221 different breeds of pedigree dog to ... to train than others. This doesn’t mean that they don’t make great pets ...

Grouping several breeds together for third place, he mentioned that small dogs can be particularly difficult to train. He added: "The most aggressive, stubborn, hard to train are the little dogs.