My adult kids have two Yorkies and two Maltese that have all but one,come into heat at the same time. They were out of disposable diapers to cut to fit. I think they really wanted to just save the expense. So they asked me if I could make them diapers like I made my DGD's for their dolls. So I got busy and drafted a simple pattern. So far I have made 3 of them, and they fit the dogs from 4 lb thru 7 lb. Be sure to check the measurements it prints out against the ones I noted on pattern to be sure it prints the same size.
Doggy Diaper Pattern