For dogs, citrus scents are the enemy. Citrus scents like lemon, lime, oranges, and grapefruit–especially in high concentrations often found in household cleaners or essential oils–can cause irritation to your pup's respiratory tract, so keep any fresh citrus fruits out of your dog's reach. You know–just in case.

A dog's sense of smell is roughly 40 times more powerful than a human's, meaning many scents we find pleasant are physically overwhelming for them. Dogs generally loathe the smell of citrus (lemons, oranges, and grapefruits) because the acidic aroma is highly irritating to their respiratory tract. They also strongly dislike the smell of vinegar, which is why it is often used as a natural deterrent to keep dogs away from certain furniture. Pungent herbs and spices like chili powder, cayenne pepper, and even fresh mint or rosemary are often avoided by canines. Beyond natural scents, dogs are repelled by cleaning products containing ammonia or bleach, as well as the strong chemicals in nail polish and perfumes. While these scents can be used as training tools to prevent "marking" or chewing, you should never apply them directly to a dog. Understanding these aversions is key to creating a comfortable home environment; for example, using a citrus-scented floor cleaner might make your dog feel restless or anxious in their own living space.