Chocolate Toxicosis: Tips for Treating Dogs Who Treated Themselves
Chocolate toxicosis: it’s time for a refresher. Although it would be nice to tell people to avoid chocolate altogether so there are no potential issues, that is not realistic, and we know a lab would still find chocolate even if you swear there was none in the house, so it is better to be prepared. With that in mind, here is a quick summary of how different chocolate may affect dogs:
White Chocolate
Despite its name, white chocolate is NOT actually chocolate. I know it is such a big disappointment (sorry to all those white chocolate lovers out there), but good news for your dog! Although you do not have to worry about any chocolate toxicity issues with white chocolate, you should still monitor for GI upset/pancreatitis issues, considering the dairy and fat content.
Milk Chocolate
Unless it is a tiny dog, dogs usually have to ingest a lot of this to be a problem, so I typically ask other questions like: was the chocolate wrapped in something, so I have to worry about the wrapper(s) causing an obstruction? Or did the chocolate contain anything else in it? For example, my own dog ate a fruit & nut milk chocolate bar. I was more worried about the raisins in it than the actual chocolate. He looked confused as I made him vomit his sneaky treat to himself (do not worry, he was fine; different topic for a different day).
Dark Chocolate
For dark chocolate, I will admit I usually use a chocolate toxicity calculator to determine if treatment is necessary or if it will be okay to monitor the dog. Both VIN and Merck have very nice chocolate toxicity calculators that notify you of what signs to expect based on the dog’s weight, what kind of chocolate was ingested, and how much.
Baker’s Chocolate & Cocoa Powder
I think of that scene from “Gilmore Girls” where Luke is watching Lorelei’s dog, and he ingests some baking chocolate. Luke subsequently picks up the dog and rushes him to the local veterinarian. I applaud Luke’s decision to rush him to the vet, maybe less so going to the vet’s house in the middle of the night. Unfortunately, it doesn’t take much baker’s chocolate and cocoa powder to reach toxic levels, according to Cornell University, “where as little as 0.1 ounces [of baking chocolate] per pound of a dog’s body weight may be lethal” and even less cocoa powder. So, intervention is usually recommended if any is ingested.
Clinical Signs of Chocolate Toxicosis
Clinical signs of chocolate toxicosis usually occur within 2–12 hours of ingestion and typically last 12-36 hours. However, it may persist for up to 72 hours in severe cases due to its slower absorption and potential for reabsorption. What causes these clinical signs is the methylxanthines, theobromine, and caffeine. However, significantly more theobromine is found in chocolate than caffeine. When fewer methylxanthines are ingested (20-40 mg/kg), more mild signs like vomiting, diarrhea, polydipsia, and restlessness are seen. As more methylxanthines are consumed (40-50 mg/kg), the chances of complications significantly increase as cardiotoxic effects are seen, including tachycardia, arrhythmia, hypertension, tachypnea, and hyperthermia. Tremors that can progress to seizures are seen at higher doses (≥60-80 mg/kg). Although these are general guidelines of when to expect certain signs of chocolate toxicity, it is essential to remember all dogs respond differently. A dog can still have complications even if it’s a “safe” amount, so close monitoring is always recommended.
If you are concerned at all, it is never a wrong choice to recommend intervention. Intervention usually involves symptomatic/supportive care and management of potentially life-threatening clinical signs if needed. Stabilization of critical patients is the first priority, which aims at managing any arrhythmias or tremors/seizures.
Treatment
Seizures
If not status epilepticus, first try:
- Diazepam: 0.5-2 mg/kg slow IV or 0.5 mg/kg rectally
- Midazolam: 0.5-1.0 mg/kg IV or 0.2 mg/kg intranasally
If benzodiazepines ineffective or status epilepticus:
- Propofol: 3-6 mg/kg IV or 0.1-0.6 mg/kg/min IV as a CRI
- Phenobarbital: 4-16 mg/kg IV to effect
- Inhalation anesthesia
Tremors
Without seizures:
- Methocarbamol: 50-220 mg/kg slow IV to effect; do not exceed 330 mg/kg/day
Arrhythmias
Ventricular tachyarrhythmias:
- Lidocaine: 1-2 mg/kg IV initially followed by 0.025-0.08 mg/kg/min IV CRI
Sinus tachycardia, supraventricular tachycardia, or refractory arrhythmias:
- Metoprolol: 0.04-0.06 mg/kg slow IV followed by up to 0.2-1.0 mg/kg PO q 8-12 hrs once stable; “beta-blocker of choice because it does not delay urinary excretion of methylxanthines,” according to VIN
- Propranolol: 0.02-0.06 mg/kg slow IV followed by 0.2-1.0 mg/kg PO q 8 hrs once stable; may delay urinary excretion of methylxanthines
- Esmolol: loading bolus of 50-100 µg/kg IV (maximum 500 µg/kg) followed by 50-200 µg/kg/min IV CRI
Bradyarrhythmia without hypertension:
- Atropine: 0.01-0.044 mg/kg IV, IM, SC
Decontamination:
If the patient is stable, treatment involves emesis if the chocolate ingestion was within a few hours (4-6 hours) prior to presentation:
- Apomorphine: 0.02-0.04 mg/kg IV or 0.08 mg/kg IM, SC
- Ropinirole: 3.75 mg/m2 topically to the eye (see accompanying dosing chart to the right)
In more critical patients or if desired results not achieved by inducing emesis, gastric lavage can be performed as long as a patent airway is maintained via intubation and respiration is controlled.
Regardless of timing, activated charcoal (1-4 g/kg PO) should be administered every 12 hours until no longer symptomatic, monitoring electrolytes if used repeatedly.
Supportive Care:
Hyperthermia should be addressed, overly aggressive cooling measures should be avoided, and oxygen therapy should be provided as needed. If symptomatic, fluid therapy is recommended to “help stabilize cardiovascular function and hasten urinary excretion of methylxanthines,” according to the Merck Veterinary Manual. Along these lines, a urinary catheter may be placed in more severe cases, or the dog should at least be encouraged to urinate frequently by walking. Antiemetics and/or GI protectants may also be given.
With all this in mind, I like to think I am saving my dogs’ lives by ingesting the chocolate in my house on their behalf. At least now, you will hopefully have peace of mind knowing what to do if your dog ingests some chocolate.