Jeremy started lifting his leg at 5 months . But only to pee. He has just been desexed at around the 8 month mark I think he is, and 5 days ago he lifted his leg inside and marked my daughters couch . He has never done this before. Needless to say its back to square one on the toilet training .I swear this age is harder than when they are younger. Boys!!! you have to every thing twice with them .