Well hi there, I am not a breeder, but I have a almost 9 month old yorkie name Nemo, and he slowly started lifting his leg up here and there, and now it is eveywhere, I did not even know that he was lifting in the house until recently, because I never seen him do it, but I was finding pee in odd places by my trash can, up against a wall, and i noticed that after I mopped it would still smell like pee, and I starting paying closer attention, and I caught him one day peeing on a basket of clean clothes, and I like to have had a fit so needless to say right now he isn't getting much free run around time, just can't have my things full of pee, and smelling pissy all the time, I just recently have been having an easier time with potty training, but he still is marking everywhere even outside he lifts on everything, but he is going to be fixed....his appointment is on the 18th of this month.....I have also heard that once you breed them it gets worse (the marking thing)....so I can't offer any advice really just my experience with Nemo leg lifting.....
Good luck!!!
Gale
