15. Cherry Pits
Cherries themselves are not the main villain. The pits are. Cherry pits contain cyanide — yes, that cyanide, the poison from old detective movies. The flesh is mostly safe, but the pit, stem, and leaves contain amygdalin, which converts to cyanide when chewed.
Symptoms: difficulty breathing, bright red gums, dilated pupils, shock. A single pit rarely poisons a medium dog. Two real dangers exist — choking and intestinal blockage, and eating multiple pits if a dog raids a bowl. If you have a cherry tree, pick up fallen fruit. The next one involves a fruit you probably have right now.