Cocoa Mulch, which is sold by Home Depot, Foreman's Garden Supply and other Garden supply stores, contains a lethal
ingredient called 'Theobromine'. It is lethal to dogs and cats. It smells like chocolate and it really attracts dogs. They will ingest this stuff and die. Several deaths already occurred in the last 2-3 weeks. Just a word of caution, check what you are using in your gardens and be aware of what your gardeners are using in your gardens.
Theobromine is in all chocolate, especially dark or baker's chocolate which is toxic to dogs. Cocoa bean shells contain potentially toxic quantities of theobromine, a xanthine compound similar in effects to caffeine and theophylline. A dog that ingested a lethal quantity of garden mulch made from cacao beanshells developed severe convulsions and died 17 hours later. Analysis of the stomach contents and the ingested cacao bean shells revealed the presence of lethal amounts of theobromine.
Although the mulch has NO warnings printed on the label, upon further investigation on the company's website, this product is HIGHLY toxic to dogs and cats. Cocoa Mulch is manufactured by Hershey's, and they claim that 'It is true that studies have shown that 50% of the dogs that eat Cocoa Mulch can suffer physical harm to a variety of degrees (depending on each individual dog). However, 98% of all dogs won't eat it.'
This Snopes site gives the following information:
http://www.snopes.com/critters/crusader/cocoamulch.asp