"Avocado contains a toxic element called persin which can damage heart, lung and other tissue in many animals. Avocadoes are high in fat content and can trigger an upset stomach, vomiting or even pancreatitis. The seed pit is also toxic and if swallowed can become lodged in the intestinal tract where it may cause a severe blockage which will have to be removed surgically. Since avocado is the main ingredient in guacamole be sure and keep your dog out of the dip."