Do you alter the cost for TWO big dogs?

I just got a request for two large dogs (130lb and 140lb), and while I am not overly worried about anything--I am a little concerned that they might be more work than my normal client (60lb, quite, calm). My normal rate is $50 a night an $35 a night for each additional dog. I have heard of folks modifying the cost after talking to owners and learning details (like size and needs).

My question is, would you alter the rate? And if so, by how much?

I am going to be solo carrying for these dogs, and I have a large fenced in back yard, but my home living spaces are relatively small.