Cocoa mulch is toxic to dogs

This one’s no urban myth: the cocoa hulls sold as mulch smell good to dogs (and some cats) and are toxic––even fatal––if ingested. These are the hulls of chocolate beans and contain the same ingredients that are poisonous to dogs in chocolate: theobromine and caffeine. The hulls smell like chocolate; apparently some dogs find this very appealing and snarf it up, while others don’t bother with it, but there’s no way to tell.

Of course dog and cat owners should avoid using this mulch, indoors or out. Those who care about animals, even if they don’t have any, should do the same. But more than that, we must keep an eye on what our pets eat when we take them other places. Animals may not show any symptoms until as late as the next day and then begin with convulsions. By then treatment is too late.


Cocoa hull mulch with a quarter for size comparison. Color fades with age.
Photo: ASPCA’s very informative page on the toxicity of this material.

According to the urban-myth busters at, who verify the internet warnings on this topic, some producers of cocoa hull mulch say that they have put the material through a process which extracts all theobromine and caffeine, but why take a chance at your own house? and as to what someone else has used, there’s no telling. I checked the webpage of one major producer, National Cocoa Shell, and there was no mention whatsoever of toxicity or extra processing to avoid toxicity.

If your pet eats even a small amount of chocolate-scented mulch it would be safer to take him or her to the vet. The ASPCA is quoted, in the snopes article, as to the toxicity of small amounts:

Cocoa beans contain the stimulants caffeine and theobromine. Dogs are highly sensitive to these chemicals, called methylxanthines. In dogs, low doses of methylxanthine can cause mild gastrointestinal upset (vomiting, diarrhea, and/or abdominal pain); higher doses can cause rapid heart rate, muscle tremors, seizures, and death.

Eaten by a 50-pound dog, about 2 ounces of cocoa bean mulch may cause gastrointestinal upset; about 4.5 ounces, increased heart rate; about 5.3 ounces, seizures; and over 9 ounces, death. (In contrast, a 50-pound dog can eat up to about 7.5 ounces of milk chocolate without gastrointestinal upset and up to about a pound of milk chocolate without increased heart rate.)

Note that milk chocolate is less toxic to dogs than dark chocolate, the kind we have all been encouraged to eat in moderation for our own health.

The toxicity of chocolate and cocoa hulls to pets underlines the point that what is healthful for humans may be fatal for our pets.

Another example: NSAIDs (Non-steroidal anti-inflammatory) pain medications such as aspirin; Tylenol (active ingredient acetaminophen, called “paracetamol” outside of North America); Advil, Motrin, etc. (ibuprofen); Aleve, Anaprox, Miranax, Naprogesic, Naprosyncan, etc. (naproxen) can be deadly to cats and harmful to dogs. They can cause intestinal perforation, internal bleeding, and other life-threatening conditions. They’re not that great for people, either, in long-term use, but we have more resistance than dogs, cats, rabbits, and ferrets.


Photo from

To take aspirin as an example: Children’s aspirin contains 81 mg of salicylate, regular aspirin 325 mg, Pepto-Bismol 300 mg per tablet and 262 mg per 15 ml (1 tbsp.) of liquid. Numerous other products contain aspirin. The toxic doses of salicylate for dogs and cats are very low:

Dogs: 22 mg per pound per day. (A children’s aspirin could be toxic to a tiny dog, or a puppy whose immature digestive system is even more vulnerable)

Cats: 11 mg per pound per day, may see symptoms after one dose.

Don’t take these numbers as permission to calculate safe doses for your pets, if only because other factors affect toxicity, such as age and health of the individual animal. Call your vet and ask. If your vet or vet tech seems vague or not concerned, err on the side of caution for the time being and get a better opinion.

The Drs. Foster and Smith site gives more details on aspirin toxicity:

Signs (in dogs and cats) usually develop within 4-6 hours with an acute overdose. They include depression, lack of appetite, vomiting which may contain blood, abdominal pain, increased respiratory rate, acute kidney failure, weakness, coma, and death.

Chronic lower doses in dogs may lead to stomach ulcers and perforation, toxic liver inflammation, and bone marrow suppression resulting in anemia.

Immediate Action
Induce vomiting and seek veterinary attention.

Favorable, if treatment is started early. Poor, if symptoms are present when treatment begins.

Invest in that ounce of prevention and keep your pets safe.