I had an intact male that never once marked in the house. However, the vet I have is a clinic, three vets work there, so we see whoever happens to be working the day of the appointment. Chief hated the male vet there, and whenever we got him, he would lift his leg and mark the wall. That's the only time I ever saw him do that. It was like he was dissing the guy. Wolfie still squats and pees on his own feet.