Good Morning Angela and welcome. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
I am so sorry to hear about Rosso's issue....I know this is frustrating since you love him so much...
Unfortunately, this is a normal instinctive issue in some dogs. There are a few tips that will help. One is to place aluminum foil where he urinates. The noise of this will cause Rosso to be startled and stop. make sure to clean these areas with a good odor neutralizer such as Nature's Miracle to discourage this behavior.
This behavior is often due to stress froma territory issue so purchase a DAP Collar available at the pet store, Angela. This is a canine pheromone that acts as a calming agent and will help since you often cannot catch him.
If this gets worse, I have had clients have luck with an ultrasonic collar. You will have to be present when this happens and use this device to startle him. I have also had good results using a coke can with pennies to shake and startle him and then say a strong NO!!
Here is a LINK with more tips:
Does that make sense to you, Angela?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please Reply so I can clarify for you
Sincerely, XXXXX XXXXX