Chocolate Toxicity in Dogs

23 February 2024 -
News

Chocolate is known to be toxic to dogs due to the presence of methylxanthines (theobromine and caffeine) and most owners immediately take their dog to the clinic after ingestion. The first time a chocolate intoxication in a dog was published was in 1942.

The toxicity danger depends on the type of chocolate ingested because different types of chocolate have different quantities of methylxanthines. High cocoa content chocolate is known to be more toxic than milk chocolate. White chocolate does not have enough methylxanthines to induce intoxication in dogs.

Maximum serum levels are reached at 30 to 60 minutes for caffeine and after 2 hours for theobromine. Furthermore, caffeine is metabolized into theobromine. They are both metabolized in the liver, excreted via bile ducts and undergo enteropathic circulation.

Due to the effects of methylxanthines in the canine organism, the most common clinical signs observed, depending on the dose, are:

  • Theobromine:
    • 20mg/kg: Mild signs as agitation.
    • 40mg/kg: Tachycardia, hyperthermia hypertension, arrhythmias.
    • 60mg/kg: Ataxia, seizures, tremors, and coma.
    • 100 to 200mg/kg: 50% of dogs die.
  • Caffeine:
    • There is no data in the literature about the minimal dose of caffeine that induces clinical signs.
    • 110mg/kg to 200mg/kg is lethal.

 

There is no antidote against methylxanthines, so the treatment is symptomatic after decontamination:

  • Decontamination treatment:
    • Emesis induction with apomorphine
    • Activated charcoal over a period of 72 hours
  • Symptomatic treatment:
    • Fluid therapy (and correction of electrolyte deviations)
    • Sedatives (midazolam, diazepam)
    • Antiepileptics (phenobarbital)
    • Antiemetics (maropitant, metoclopramide)
    • Anti-arrhythmic drugs (Beta-blockers for sinus tachycardia and lidocaine for ventricular arrhythmias)

 

The prognosis for chocolate intoxication in dogs, after decontamination and symptomatic treatment is good.

Weingart, C, Hartmann, A, Kohn, B, Chocolate ingestion in dogs: 156 events (2015-2019), 2021, Journal of Small Animal Practice, 62:979-983.
DOI: 10.1111/jsap.13329