Discourage aphids by spraying leaves and stems with a diluted solution of Ivory soap. You might have to repeat the process several times to control infestation, but it's a safe, inexpensive alternative to chemical pesticides. Also, if you buy your peppers from a greenhouse, be sure to check the undersides of the leaves for aphids before bringing them home. At 3 to 4 inches in length, they're easy to spot and best removed by hand. Cats are notorious for eating pepper seedlings.
Dogs are notorious for chasing cats.
Unfortunately, they also enjoy digging in the garden. Birds eat peppers. Cats eat birds. It's a vicious circle. It seems everyone wants to know.