Cocoa Mulch, which was sold by Home Depot, Foreman’s Garden Supply and other garden supply stores, contains a lethal ingredient called ‘Theobromine’. It is poisonois for dogs and cats. Cocoa Mulch smells like chocolate and it attracts dogs. They may ingest Cocoa Mulch and if they eat a lot of it, they can die quickly. Just a word of caution, check what you are using in your gardens!
Your dogs may also find cocoa mulch out on walks, so be careful!
Many garden-related products can be toxic to dogs, like slug bait and weed killers, so please take that all into account when you shop! This warning first came out in 2001. I think Hershey’s is no longer selling Cocoa Mulch, as the link to it is broken, just redirects back to the home page. But there are probably other brands out there that use cocoa beans for mulch. I imagine coffee as mulch has a toxicity problem, too, except dogs don’t seem to like it as much.
Theobromine is in all chocolate, especially dark or baker’s chocolate, which is toxic to dogs in large amounts. Cocoa bean shells contain potentially toxic quantities of theobromine, axanthine compound similar in effects to caffeine and theophylline. A dog that ingested a lethal quantity of garden mulch made from cacao bean shells 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.