Would my landlord allow me to have my dog living at the house?

Dear Mr Landlord,
I would like to start by saying how happy I am at the moment living at your property, it is everything I wanted in terms of living space and location since I moved to San Francisco.
There is one thing though that I have wanted to ask you and it is regarding Yiyo. Yiyo is my dog, a 50-pound labrador that has been the perfect companion and a true friend since I was a child. Yiyo used to live with my parents as I knew I could not have him live with me at your property, but things have changed recently as my parents are moving to Europe. Yiyo is a very well-behaved dog, trained by professionals since he was 6 months old, and I think he would do a very good job keeping the block and the property safe in view of the recent burglaries that have taken place. I also see value in him being able to live at the property with me to help me keep rats off the premises, which are quite common around due to the nearby forest. I really appreciate you giving this request a thought as I am sure if you allow it we will both greatly benefit from your decision.
Sincerely yours, FC.