Thanks for all of the comments and sorry for such a delay in my response.
I'm very grateful that I am able to take him to work. Now that he is older and I have changed from three to two feedings a day and I trust him at home I no longer take him to work everyday.
He is very friendly, I'm from the San Francisco Bay Area and take him to Fort Funston so he gets to meet and play with other dogs. I have yet to meet another Mastiff owner though.
Here are some pics of him. This first one is him at 8 months trying to bring a branch into the house. The other one is of him at 9 months. He seems to really like hanging out in the backyard even on rainy days.
View attachment 58836 View attachment 58837