Kitty’s licking her paws after walking in nutmeg sprinkled on the kitchen counter, and Fido just gobbled the dark chocolate that dropped to the floor. A baking nightmare. Now what?
Holiday gatherings keep us busy and distracted, and our pets can get into trouble if they eat foods meant for human consumption. We might hear less about cat poisonings because cats are more discriminate eaters, while a dog will scarf down almost anything that hits the floor without thinking (yes, even batteries, human medicines, dishwasher tablets, Christmas ornaments, and toys, among other things). As I discussed in my November blog, it’s the dose that makes the poison. While this is also true for dogs and cats, there are differences in how certain foods are metabolized that render them more toxic for our furry friends.
Nutmeg contains myristicin which is considered the major substance that produces its toxicity. Cats are sensitive to nutmeg, and ingesting one teaspoon of ground nutmeg is toxic for Kitty. After ingestion, cats develop acute mental status changes, i.e., changes in their behavior, such as confusion, stupor, or frenzied anxiety, and liver damage. The liver is primarily responsible for detoxification, and when it doesn’t function properly, toxins normally rendered harmless through metabolism increase in the bloodstream. The build-up of these toxins can produce a brain disorder known as hepatic encephalopathy. Nutmeg is also toxic for dogs, and symptoms of poisoning include high blood pressure, increased heart rate, disorientation, vomiting, and seizures.
Chocolate derived from Theobroma cacao beans is an example of a food safe for human consumption but toxic for dogs and cats due to the differences in how it is metabolized. The main ingredient in chocolate is theobromine and, to a lesser extent, caffeine. These methylxanthines—theobromine and caffeine—are responsible for toxicity in dogs. Dogs have a longer theobromine serum half-life compared to people, so it takes longer for a dog to completely eliminate theobromine from their body. The elimination half-life is the amount of time required for the concentration of the drug to decrease by half of its original concentration. After the peak serum theobromine concentration is reached in dogs, it takes about 18 hours to eliminate half of it, while in humans, the serum half-life is only about six to eight hours. The slower elimination in dogs allows theobromine to accumulate to toxic levels with delayed symptoms.
Symptoms of chocolate poisoning include vomiting and diarrhea, panting, increased thirst and urination, abnormal heart rhythms, and seizures. Toxicity depends not only on the amount of chocolate ingested but also on the dog’s weight since symptoms of theobromine poisoning begin at 20 mg/kg. The type of chocolate makes a difference, too—unsweetened Baker’s chocolate and dark chocolate have higher methylxanthine concentrations than milk chocolate.
Xylitol is another food substance commonly consumed by people but toxic for dogs. Xylitol is a food sweetener found in candy, sugarless gum, baked goods, sugar-free desserts, other foods, and some kinds of toothpaste. After ingestion by a dog, xylitol is rapidly absorbed and stimulates the pancreas to release insulin. This sudden insulin release causes the blood sugar to drop, producing hypoglycemia. Untreated hypoglycemia can be life-threatening. Symptoms of xylitol poisoning include vomiting, lethargy, incoordination, and seizures. Cats are less likely to eat sweets and thus less affected, but ferrets have shown similar poisoning symptoms as in dogs.
Although vigilance regarding the food treats we give our animal family is necessary, holidays shared with our pets are fun. When getting ready for the festivities, brush your pet’s teeth with toothpaste marketed for pets, not humans, secure all the yummy chocolate, cookies, and spices away from animal kitchen counter surfers, and enjoy the day with Kitty and Fido.
ASPCA Animal Poison Control 888-426-4435