Avocado has been known to cause problems in many animals, from horses to sheep, rodents to birds, and even fish. This is because they contain a chemical called persin, which can cause heart failure, breast tissue infections, possibly even death. Persin is most concentrated in leaves, but it is also present in the seeds, stem and meat of the avocado.

Dogs are more resistant than other animals to persin, but that certainly does not mean avocados are dog-safe. Consuming any part of the avocado plant can lead to vomiting and diarrhea, which is why avocados often make top ten foods that are harmful for dogs.