“Mistletoe, holly, Santa Claus jolly… and, oops! The pet’s not feeling so well.”
Not the best theme song for the holiday season. Although we often treat our pets like furry people, when it comes to holiday foods, it is important to keep their unique limitations in mind.
Left-over fat-laden holiday fare, especially meat scraps, can induce pancreatitis in pets. Severe inflammation of the pancreas typically presents as abdominal pain, vomiting and bloody diarrhea. Additionally, table scraps containing garlic or onions can lead to canine and feline stomach and intestinal damage from thiosulfate toxicity. Acute exposure may induce hemolytic anemia (destruction of red blood cells), but severe cases can cause a lack of oxygen to the brain. Because the effects of thiosulfate exposure are additive over time, avoidance is the safest policy.
Xylitol, a sugarless sweetener found in many low carbohydrate (diabetic) baked goods and sugarless gums and candies, is a canine toxin. A life-threatening drop in blood sugar (hypoglycemia) occurs with vomiting, weakness, and sometimes seizure; liver failure may also develop. One stick of xylitol gum can sicken a 20 lb. dog. Raisins, currents, grapes and foods that contain them (e.g., fruitcake) can induce acute kidney failure in dogs. Small dogs can become ill on only four grapes or raisins. Risk in cats is uncertain, as they generally disdain grapes and fruitcake.
Most serious or fatal holiday poisonings occur in dogs that have helped themselves to baking chocolate (semi-sweet or unsweetened) or boxed holiday chocolates placed under trees or on low tables. Chocolate and cocoa contain theobromine, a highly toxic substance to pets. Small amounts of chocolate can cause vomiting and diarrhea; large amounts (< 2 oz. for a small dog; ~14 oz. for a large dog) can cause seizure and heart arrhythmia. As a rule, darker chocolates tend to contain higher theobromine contents. Due to a lack of “sweet” taste receptors, ingestion risk is lower in cats than dogs.
Although not technically food, pets don’t always view holiday plants as strictly decorative. Poinsettias which have a reputation for being highly toxic are actually only mildly so; snacking on leaves and stems rarely causes more than mouth/stomach irritation and vomiting. The real dangers are lilies, holly, and mistletoe, plants frequently used in holiday bouquets and decorations. A few bites of lily can produce kidney failure in a curious feline. Nibbling on holly leaves or berries can cause excessive salivation with a potential for intense vomiting, diarrhea and nervous depression in dogs and cats, depending on the amount eaten. More seriously, the consumption of mistletoe leaves and berries can induce significant vomiting and diarrhea in pets, but also breathing difficulties, erratic behavior, collapse, and death. As a preventative measure, florists usually replace mistletoe berries with plastic substitutes. Of lesser concern are evergreen needles and water preservatives. Oral irritation typically discourages grazing on pine needles which can induce vomiting, diarrhea, lethargy, trembling and posterior weakness. Tree and floral preservatives and the stale bacteria-laden water that accumulates in tree stands and vases are mildly toxic. Although not advised, drinking such water rarely causes more than gastrointestinal upset.
Prior to the holiday season, we encourage you to plan with your furry family members in mind. In addition to pet-proofing, be familiar with the current number and address to a nearby emergency veterinary hospital.
 ASPCA’s Pet Poison Control Hotline at 888-426-4435