In this case, in mulch — you know, Sisters and Brothers, the mulch that you use on your flower and veggie beds to help them grow better. It turns out that some mulch has cocoa in it and that can very bad for your pets.
While the above article isn't long it does give some decent advice about what to look for to determine if your beloved family pet may have consumed a cocoa product without your knowledge. Your Chocolate Priestess will assume that none you would abuse your pets by giving them our Sacred Substance which as you know is also a drug.
The cause is related to a chemical called theobromine which varies by chocolate type (dark, milk, white) but always poses a risk to a non-human. While this is similar to the effects of caffeine ask yourself this: If you wouldn't give your pets coffee, should you give them chocolate.
Obviously the most important reason to not give you pets chocolate is that it deprives you of this wonderful means to connect more directly with the divine. Use your sacraments wisely and that means using them for the human members of your family.
Sisters and Brothers, may you too take the time to slowly appreciate what the Divine and human ingenuity have offered you in chocolate.