I am sorry to that you lost your pet dog,they are part of the family and it is very sad when the times comes.
I also have a dog now aged 16years and is very ill i know soon that she will also have to go,I got her after our son died to try and help my wife and it did work and she has been very good and I will hate that day when it comes,but the cost in keeping her going is about £45 amonth and now I have packed up work this to us is a lot,but I can not bring myself round to take that step yet,she still gets up and walks around the garden but then sleeps all day she is on a lot of tabits about seven aday,so i do know how you feel,also we had two cats one died at 24years,and one at 26years they went within weeks of each other,I just hope that one day I will wake up and the dog has died in her sleep.