One can spend an endless amount of money on pet products that can be bought almost anyplace now, not only including big box stores, but local small shops.  Scarves can be bought for dogs and the list goes on and on.  These are the items you want REMOVED from your home when it is on the market as they have NO appeal to a buyer and call attention to animals being in the house.  It is OK to put pets outside, but keep the yard cleaned up and warn buyers and agents dogs are in an enclosure in the back yard and may bark.  Again dogs can change disposition when the owners are gone, so BE WARY!  You can sell a house with pets, but must work ahead.