Chocolate, in addition to having a high fat content, contains caffeine and theobromine. These two compounds are nervous system stimulants and can be toxic to your dog in high amounts. The levels of caffeine and theobromine vary between different types of chocolate. For example, white chocolate has the lowest concentration of stimulants and baking chocolate or cacao beans have the highest concentration. White Chocolate. Mild signs of toxicity can occur when 45 ounces per pound of body weight is ingested. Severe toxicity occurs when 90 ounces per pound of body weight in ingested. This means that a 20-pound dog would need to ingest at least 55 pounds of white chocolate to cause nervous system signs, which is next to impossible. Be aware that a much smaller amount of white chocolate may result in gastrointestinal problems.
Depending on the type of chocolate ingested and the amount eaten, various problems can occur. The high fat content in chocolate may result in vomiting and possibly diarrhea. Once toxic levels are eaten, the stimulant effect becomes apparent. You may notice restlessness, hyperactivity, muscle twitching, increased urination and possibly excessive panting. Heart rate and blood pressure levels may also be increased. Seizure activity may occur in severe cases.
Milk Chocolate. Mild signs of toxicity can occur when 0.7 ounces per pound of body weight is ingested. Severe signs occur when two ounces per pound of body weight is ingested. This means that a little less than one pound of milk chocolate can be toxic to the nervous system of a 20-pound dog.
Semi-Sweet Chocolate. Mild signs of toxicity can occur when 1/3 ounce per pound of body weight is ingested. Severe signs occur when one ounce per pound of body weight is ingested. This means that as little as six ounces of semi-sweet chocolate can be toxic to the nervous system of a 20-pound dog.
Baking Chocolate. Mild signs of toxicity can occur when 0.1 ounce per pound of body weight is ingested. Severe signs occur when 0.3 ounce per pound of body weight is ingested. Two small one-ounce squares of baking chocolate can be toxic to a 20-pound dog. This type of chocolate has the highest concentration of caffeine and theobromine and very little needs to be ingested before signs of illness become apparent.
Generally, within a few hours of ingesting a toxic amount of chocolate, signs of hyperactivity, tremors, panting and excessive urination are seen. Prompt veterinary care is recommended.
One uncommon but potential source of chocolate is in certain mulches. Cacoa bean mulch is made from the hulls of cacoa beans and when fresh has a rich, chocolate aroma. Ingestion of large amounts of fresh mulch can result in chocolate toxicity. To keep your pet safe, keep him away from the mulch until the chocolate aroma has gone. A thorough watering or heavy rainfull often reduces the potential toxicity.
Diagnosing chocolate ingestion is generally based on the owner's witnessing or suspecting ingestion and on physical exam findings. Pets that have ingested toxic levels of chocolate are generally hyperactive, panting, have increased blood pressure and increased heart rates. Dehydration may also occur if there has been significant vomiting and diarrhea.
Treatment depends on the severity of the clinical signs and may include continuous intravenous fluid therapy, medications to help control vomiting and sedatives to counteract the stimulant effects of chocolate.
Occasionally medication to reduce heart rate and high blood pressure is indicated.
Most pets treated for chocolate toxicity recover and return to normal within 24-48 hours of treatment.
Home Care and Prevention
Remove your dog from the source of chocolate and call your veterinarian immediately if you suspect your dog has consumed a toxic amount. Your veterinarian may recommend that you induce vomiting in your pet by oral administration of hydrogen peroxide. Transport your pet to your veterinarian immediately.
Home care for pets that have ingested toxic levels of chocolate is primarily aimed at reducing gastrointestinal upset and making certain that there is no access to additional chocolate. Once the nausea is gone, your veterinarian may recommend a bland diet for a couple of days.
Watch for tremors, hyperactivity or seizures. If your pet is not eating and drinking, continues to vomit, has persistent diarrhea or still seems hyperactive, consult your veterinarian for additional recommendations.