My dachshund pup toilets all over inside, even if he's just comes inside from the garden. What can I do?

A puppy has a lot to learn, so be patient. Supervise him constantly indoors, even if this means having him on a leash so you can watch for signs of squatting. When you can't be there, pop him in his crate. Take him outside every 20 minutes, whether you think he needs to go or not. Stay outside with him for 10 minutes, so as to increase the chance of him going — and then praise him like mad when he does. If he still doesn't go, return indoors, but either crate him until the next toilet break, or take him outside every five minutes! Training is about decreasing the opportunity indoors, and increasing the opportunity outdoors.