Sim dogs never accidently have puppies. You have to deliberately breed your dogs before they’ll have a litter. And you won’t even see the Try for Babies interaction unless you have a doghouse on your lot. Even once a pet house is present, the dogs must have a high enough relationship for the interaction to appear on the menu.
Place a doghouse item on your lot to gain access to the Try for Babies interaction.
If this doghouse is rockin’, don’t bother knockin’.
Just like with people, not every attempt results in a pregnancy. But when your pet does become pregnant, you get an onscreen message informing you.
Pregnant dogs get the mildly positive Pregnant moodlet.
When it’s time, your female dog pops out a random number of puppies, with a graphical flourish. The pups will have some traits and markings from their parents (or grandparents) although they may also exhibit random traits or looks. Puppies might even inherit the ability to do some tricks, if their parents or grandparents know some.
Like father, like son.
You get a message listing the number of puppies in the litter, and a reminder to name them. Click on a puppy and choose the Name Pet option.
A new litter of puppies or kittens is a big event in a household. All household members get the powerfully positive New Puppies (or New Kittens) moodlet, which boosts mood by 80 points and lasts a whole day.
Puppies are just sooooo cute. Sims look at puppies and (either autonomously or user directed) say Awwwww. This social builds Fun, and gives the Sim the Puppies! positive moodlet.