Avocado contains a fungicidal toxin, even, which allows the avocado tree to defend itself against possible fungi.

While humans remain insensitive to this toxin, this is not the case in most pets (dogs, cats, horses, rodents) which show the following symptoms when chewing or ingesting leaves of the tree, fruit or its stone: vomiting, diarrhea, dyspnea, cough, edema, listlessness.

To date, no toxic dose has been established although it is assumed that the amount ingested must be relatively large.