The Sims 4 Cats and Dogs

I had this problem too, do you have any male dogs? If not, do you know a stray, male dog? Because, if you do, then click on your female dog and see if there is a 'encourage to mate with' button. If there is, press it and select the dog to mate with, then when they have mated, see, again, if there is a 'encourage to bread with' button. Press that and see if it works. I hope this has helped!