Pet deposit in Pennsylvania

[Vi Ho]

I could not find an answer to this and wanted to see if anyone can help. 

My tenant who has rented from me for the past 4 years has asked if he can own a small dog now. It’s for his daughter who is going through a tough time. He has been a really neat and clean, low maintenance tenant. The daughter recently moved in with him after the loss of her mom.

I just renovated the house before he moved in so almost everything including the hardwood floors are new. I said no, but he responded back to say thanks for my response but he will need to discuss with his daughter to see if they can postpone the plan and look elsewhere in the future, or just not have a pet completely.

if I decide to allow small dogs only, can I collect additional pet deposit in addition to the one month’s security deposit that I’m already holding? I know PA only allows one month’s worth of security deposit if tenants stay past 1 year. I am just concerned about the damages. In addition to the pet deposit, I plan on charging additional $25 rent a month. 

just trying to see what others have done in PA and your general experience with great tenants taking on pets. 

thanks!