Chocolate and your Pets

by Dr. Barry Baker, ECC Staff Doctor 

It’s that time of year again. The holidays are fast approaching, kicking off with Halloween as the first big holiday where people will go out and buy a lot more chocolate and candies than they normally would earlier in the year. This will continue through Thanksgiving, Christmas and New Year’s. Although this can be a very fun and joyous time, a little spilled baker’s chocolate on the floor or a whole tray of dark chocolate brownies “gone missing” could lead to a fatal toxicosis of your pet. […]

Chocolate is a wonderful and delicious treat for humans, but not for our pets. It is made up of two compounds that can be deadly to your pet. Theobromine and caffeine are two types of compounds called methylxanthines that can cause a range of toxic signs in your pet, and at high enough doses can lead to death. Therefore, this time of year is a crucial time to be extra careful with placement of your chocolate and exercising prompt intervention when you think your pet might have been exposed.

Different kinds of chocolate have different levels of potency.

(See Table 1)

Type of Chocolate Maximum safe dose (ounces of choc. ingested per pound of body weight)
Milk Chocolate Less than 0.14oz per pound
Dark (semi-sweet) Chocolate Less than 0.06oz per pound
Baker’s (unsweetened) Chocolate Less than 0.02oz per pound
Dry Cocoa Powder Less than 0.01oz per pound

Milk chocolate has lowest levels of methylxanthines (white chocolate technically has insignificant levels of methylxanthines and is virtually non-toxic). Still, ingesting only one ounce of milk chocolate per pound of body weight can be lethal to your pet. Dark or semi-sweet chocolate is next up on the list above milk chocolate having higher potency. After dark chocolate comes unsweetened baker’s chocolate, and finally dry cocoa powder is the most toxic with the highest concentrations of methylxanthines per ounce.

Chocolate bars labeled as a percentage of cocoa is based off of unsweetened chocolate. Cocoa bean hulls (sometimes used in planters or as a bedding or substrate for animals) are about half as potent as unsweetened chocolate. The exact amount of methylxanthines in chocolate does vary because of natural variations in each cocoa bean that grows, as well as how each chocolate company makes and processes their products. The doses in the Table 1 are meant as a guideline only. Each individual animal can also have variable sensitivities to the methylxanthines. One particular animal of the same breed and species may react differently to a certain dose of chocolate than a similar animal wound to the same dose.

Toxic affects to your pet also vary by dose. Lower doses of ingested chocolate generally result in GI signs including vomiting, diarrhea, loss of appetite and increased thirst. Mid-range doses can result in cardiotoxic effects such as tachycardia and arrhythmias, which can be fatal. Very high doses will cause seizures and death. Development of toxic signs also can vary, with some signs being visible as soon as 2-4 hours after ingestion, but can take as long as 6-12 hours to show.
Because only a small amount of chocolate can make your pet very sick, please take extra precautions about keeping chocolate out of reach of your pets, and quickly cleaning up any spills on the floor. If your pet does ingest chocolate or if you suspect they did, call your veterinarian right away to help determine how urgently your pet should be evaluated and treated. If the dose appears to be very low, they may recommend just monitoring for GI signs at home. If there’s concern it’s a higher dose, they may recommend inducing vomiting at home to try to get as much chocolate up as possible, or bringing your pet straight to the hospital for treatment. If your pet is already acting sick, it is not safe to make your pet vomit. Your pet may already be vomiting and that shouldn’t be perpetuated, as vomiting also carries a risk of leading to aspiration pneumonia or causing ulcerations to the esophagus and stomach linings. If your primary veterinarian’s office is closed, you can call New England Animal Medical Center at (508) 580-2515 to consult about your pet or better yet, bring them down immediately. We are open 24/7.

There are also pet poison control hotlines available 24/7 that can consult not only about chocolate toxicities, but any other toxicity from other foods, chemicals, pet or human medications, etc. We recommend the ASPCA (888) 426-4435 or the Pet Poison Helpline (855) 764-7661. Both of these poison control centers do charge a one-time fee for their services and are staffed 24/7 by actual veterinarians and veterinary toxicologists that can advise you about the severity and actions needed to be taken on your pet.

Severe cases of chocolate toxicity that are showing severe, GI, cardiotoxic or neurotoxic signs will likely need hospitalization at a 24-hour hospital for continual monitoring and critical care. Such cases could become quite expensive and cost $1,000-$2,000 or more to treat.  If your pet is successfully treated, fortunately the long term prognosis is good and there are generally no lasting effects that need chronic management. Fatal doses may not be able to be successfully treated, so timing is crucial. If your pet already has underlying health problems like heart disease or neurologic disease, a severe toxicity could exacerbate and worsen those conditions. 

Please, enjoy the holidays and all the yummy treats that come with them, but take extra care to keep them away from your pets.