IMO that is really too slow. Cut out all the biscuits and keep just the kibble and ice cream if you don't have the heart to take it away.
I just took 25lbs off one dog in 2 months and yeah he lost muscle but he was so obese it is deadly. He still had about 15lbs to go by the time he went back home. 4.7lbs in a month is nothing, reduce the treats and take him to a healthy weight. Do you have pictures?