Every spring homeowners start fixing up their yards getting ready for summer, and one of the first thing on the list can often be some fresh garden mulch. But be careful on what you’re using. There seems to be a potentially hidden danger in a certain type of mulch made from leftover shells of processed Coco Beans. The aroma can be enticing to dogs and if they start eating the mulch it can lead to sever illness/seizures and worst reported cases, death.

Seems this topic first started circulating in the early 2000’s, so the danger may or may not still hold true as it sounds like some manufacturers have addressed the issue. But like everything else, it’s best to do your own research and be cautious what products are used in and around your home that your furry little companions may come in contact with.
“some brands of that product have been reformulated to reduce or eliminate the potentially dog-dangerous substance it contains (theobromine)” – Snopes-

“Dr. Maureen McMichael is a veterinarian at the University of Illinois Veterinary Teaching Hospital in Urbana who specializes in emergency and critical care. She says, “Cocoa mulch is significantly more toxic than milk chocolate or even baker’s chocolate because it has quite a bit more theobromine in it.” Theobromine is the toxic compound in most chocolates that is responsible for the clinical signs seen in pets after ingestion.”  – Saturday evening post article-2010-

“Some manufacturers of cocoa mulch (such as the Cocoa Mulch brand) now proclaim that their products are theobromine-free and pet safe. Responsible pet owners should take care in their selection of cocoa mulch brands; some might prefer to choose another form of soil enhancement for their gardens, such as cedar-based products, rather than gamble their dogs won’t be attracted to or harmed by cocoa mulch.” – Snopes-

“Dr. Hansen recommends that pet owners avoid use of cocoa bean shell mulch in landscaping accessible to unsupervised dogs, or at least use it cautiously around dogs with indiscriminate eating habits. The odds of dogs dying from eating the fresh mulch are low, but those suspected of ingesting it should be examined by a veterinarian.” -AVMA.org

Here are some articles on the topic
Snopes
Saturday Post
Poison control
AVMA