There are three primary types of commercial dog repellents, including scented repellents, Liquid Fence and ultrasonic repellents Owners also have the option to make all-natural scented repellents at home.
Scented repellents are not harmful to people or animals but present a strong odor that will keep the dog away. Such repellents can be used on fences or around areas that owners want to prevent a dog from entering.
Liquid Fence is a commercial product designed to cover up the scent markings of a dog.
Ultrasonic repellents emit a high-frequency sound that humans cannot hear but will disturb a dog.
Chili pepper, vinegar and ammonia also have odors that dogs find offensive. Chili pepper can be sprinkled on the ground, but owners should place cotton balls soaked in vinegar or ammonia around the area they want to keep the dog out of rather than pouring it on the ground since these liquids can damage plant life.