When you first start you game you will receive two animals for free! You will start the game with your dog and a few days into the game you'll receive a little horse. Your new animals will still be kids, but they will grow up. Your dog will be full grown by the 1st of Fall and your horse will be an adult 1 year after you receive him.
Your dog can not have puppies with Barley's dog, Hana.
Your dog can protect your livestock though. If you leave him outside when he's all grown up, he will bark at the wild dog that appears randomly on your farm land. The two dogs will chase each other around the farm. As long as your dog keeps the bad dog occupied it can't scare any of your livestock animals that are outside. You can also hit the wild dog with your farm tools, but be careful you don't hit your own dog!
There are even toys you can buy for your dog. Won will have a Dog Ball and a Frisbee for sale once your puppy has grown up. You can use the Ball to play fetch with your dog while you are on your farm. If you loose your Dog's ball, Won will have another one for sale. The Frisbee can only be used when you're at the beach.
The horse you receive from Barley will stay with you as long as you take good care of it. Barley will come by a few days after the horse is full grown. If the horse has less then 5 hearts of affection, Barley will take the horse away. You can prevent him from repossessing your horse by taking good care of it. Your horse likes to spend time outside when the weather is good. You can even brush it.
When your horse has matured into an adult, you can use him as a portable shipping bin. All you have to do is throw something at the horse's saddlebags. The item will automatically be picked up by Zack when he arrives at 5:00 pm for shipping. You can also enter your horse into the Spring and Fall Horse Race. If you win the event you'll receive Animal points depending on how many hearts your horse has. For every heart you'll earn 2.5 Animal points.