Take care in the kitchen, too. Typical holiday staples such as grapes and raisins have been shown to cause renal failure when ingested by dogs.
Although small amounts of onions and garlic are often used in pet foods and treats to add flavor, ingestion of large amounts can cause severe red blood cell damage; cats are especially sensitive.
Macadamia nuts can cause a short-term hind-limb paralysis, and bread dough, if eaten before baking, can expand rapidly once ingested and cause ethanol poisoning.
Sweets, gum and hard candies are often problematic depending on ingredients. Chocolate contains a theobromine, a chemical that can affect the heart, kidneys and central nervous system. Dark chocolate and baker's chocolate contain higher concentrations of theobromine and are more toxic than similar amounts of milk chocolate.
Sugar-free gums and candies that contain the sugar-substitute xylitol can lead to quick onset of toxic clinical signs that may include a rapid decrease in blood sugar and possible seizures.
Think carefully before placing mistletoe or holly in low-lying areas, but put poinsettias anywhere you like. The effects of the poinsettia, long believed poisonous, are generally benign, says Dr. Anthony Knight, author of A Guide to Poisonous House and Garden Plants and professor of clinical sciences and toxicology at Colorado State University School of Veterinary Medicine and Biological Sciences.