Chocolate Toxicity Hits Home

By Patrick Mahaney, VMD, CVA, CVJ on Dec. 4, 2012

One otherwise uneventful evening, I returned home from a movie to receive an extra enthusiastic greeting from my dog, Cardiff. As usual, we went for a walk outside in our West Hollywood neighborhood to give him the chance to eliminate after being confined inside for a few hours and before we settled in for our night’s sleep.

During our walk Cardiff produced two bowel movements, which is an unusual pattern for him. Most evenings, Cardiff is just a single time pooper and sometimes has to be coerced to do so in the landing strip of his favorite grass in front of our home.

Once inside, I found the paper remnants of an entire 3 oz. bar of Theo Orange 70% Dark Chocolate; consumed by an amped up pooch who eagerly oversaw the process of my discovery. The chocolate bar had been packed in my luggage (as a gift for a friend) in preparation for an early morning flight to NYC for Westminster 2012 (see Notes from the Westminster Dog Show Day 1 and Day 2). I neglected to close the suitcase’s zipper, so Cardiff had ample opportunity to access the tasty treat with minimal effort.

Yes, as a result of my negligence, my own dog had committed a deed which I continuously warn my clients and readers! Had I used proper foresight, this preventable episode of dietary indiscretion would have been averted.

Why am I concerned about Cardiff consuming chocolate? Theobromine, a member of the methylxanthine chemical class (which also includes caffeine), is found in varying concentrations in chocolate. Unlike humans, dogs slowly metabolize theobromine and are more susceptible to toxicity from chocolate consumption. The common body systems that are affected and their associated clinical signs include (but are not limited to):

Cardiovascular — increased heart rate and arrhythmia

Gastrointestinal — vomiting, diarrhea, and increased water consumption

Neurologic — restlessness, muscle tremors, and seizure activity

Urogenital — increased urination or urinary incontinence

The highest theobromine concentrations are found in baking and dark chocolate, while semisweet and milk chocolate contain lesser but still concerning levels. Chocolate flavored commercial products and baked goods have the lowest theobromine concentrations. Fat, sugar, and other ingredients (alcohol, preservatives, sugar alcohols, etc.) can also exacerbate the signs of chocolate toxicity.

At this point I elected to stop berating myself about my irresponsibility as a pet owner and to focus on Cardiff’s health. It was obvious that Cardiff had consumed all the chocolate himself (as there are no other pets in the household), but did he consume enough to be toxic?

I checked Veterinary Partner’s chocolate toxicity calculator and realized that Cardiff ate a potentially toxic dose (2.8 oz. for a 20 pound pet). So, Cardiff cooperatively entered his car carrier and off we went to the emergency hospital. Fortunately, I do relief work at this facility and was able to immediately start and direct Cardiff’s treatment.

Here was my plan:

Emesis induction

I needed Cardiff to vomit (emesis), so he received an intravenous injection of Apomorphine. As it had been hours since he’d eaten dinner, having a stomach full of food helps to promote clearance of undesirable gastric contents. So, I fed him a can of Hill’s Prescription Diet A/D before his ingestion. Within five minutes, Cardiff produced three piles of vomit that had an uncanny resemblance to chocolaty A/D.

Emesis Reversal

Cardiff received an injection of Naloxone, which partially antagonizes the effects of Apomorphine to reduce the further urge to vomit.

Antiemetic and Antacid Drug

Cardiff received injections of Cerenia (maropitant citrate) and Pepcid (Famotidine) to further diminish vomiting and reduce his stomach acid level. (respectively)

Activated Charcoal

This black, thick liquid binds to toxins in the digestive tract to prevent their absorption and facilitate clearance in the bowel movements. The ASPCA’s Animal Poison Control Center recommends not using charcoal containing Sorbitol (a sugar alcohol which facilitates digestive clearance) due to the potential risk of inducing electrolyte abnormalities.

Fluid Therapy

To promote faster excretion of chocolate’s stimulants through the kidneys and to make up for body water lost through vomiting or potential episodes of diarrhea, Cardiff received a dose of subcutaneous (under the skin) fluids.

Cardiff readily made a full recovery and his appetite was normal the next morning. Yet, he had an increased urgency to defecate and produced softer/darker (nearly black) bowel movements from the activated charcoal for the next 24 hours.

To document the process of emesis induction, I created two videos of Cardiff becoming nauseous and ultimately vomiting:

Cardiff Chocolate Toxicity Emesis 1

Cardiff Chocolate Toxicity Emesis 2

Hopefully, you will learn from Cardiff’s and my experience in dealing with this common and very preventable canine toxicity. I certainly did and feel fortunate that my canine companion was minimally sickened by my parental oversight.