1. Chocolate, caffeine and coffee
Many people realize that chocolate can be hazardous for pets, but they might be unaware that coffee and caffeine should also be avoided. All three of these of these contain substances called methylxanthines, which, when ingested by pets, can cause a variety of adverse side-effects, including seizures and death.
2. Christmas tree water
While humans typically won't be tempted to slurp from the bowl of water holding the tree, animals have been known to confuse the tree bowl with their water dish. According to the Best Friends Animal Society, Christmas tree water is a breeding ground for germs and bacteria, and could cause nausea or digestion problems if ingested by furry friends.
3. Macadamia nuts
Macadamia nuts, often found in candy and baked goods, can cause depression, hypothermia, tremors, weakness and vomiting in canine companions. It would probably be best to err on the side of caution and keep them away from your cat, too.
4. Yeasty bread dough
Uncooked yeast dough can cause some serious upsets to your pet's digestive system. The dough can expand in an animal's digestive system and rupture the stomach or intestines. The risk decreases once the bread is already cooked, so it's OK to give your pet a few pieces of baked bread, provided that it doesn't take up more than 10 percent of your pet's daily caloric intake.