Happy Pet Birthday Letter adds a small, fun pet themed birthday letter to Stardew Valley.

By default, your dog sends you a birthday letter on Spring 20 with a Dog Treat attached. The letter is written entirely in dog sounds for a silly little pet made surprise.

You can also enable a cat letter instead, or enable both dog and cat letters. Each pet type has its own configurable date, so you can set separate “birthday” days for your dog and cat if you want.