Most dogs are opportunistic and will eat almost any food they encounter if given the chance. Dead animals and garbage are obvious no-nos for your dog, but dog owners should also be aware of foods that might not seem problematic but that can lead to severe or even life-threatening issues.
It should go without saying that dogs should not be allowed access to alcoholic beverages. Excessive amounts can lead to a coma or may be fatal. Additionally, the hops found in beer can lead to seizures and death. Coffee and tea contain caffeine, theobromine and theophylline, which in low doses may cause vomiting and diarrhea and in higher doses can lead to increased heart rate, cardiac arrest, seizures and death.
Fruits and Vegetables
Most fruits and vegetables are as healthy for dogs as they are for people. Others, such as avocados, may cause vomiting and diarrhea. Onions and garlic can cause a type of anemia if fed in large or consistent doses; garlic is less potent than onions. The pits from stone fruits and seeds from other fruits could cause an intestinal obstruction. Certain mushrooms may be toxic, just as with humans. Grapes, raisins and currants can cause kidney failure, even in small amounts, due to an unknown toxin.
Meat and Dairy Products
Some cooked meats, especially turkey with the skin, are high in fat and may cause pancreatitis in dogs if fed in excess. An excessive amount of fish can lead to a thiamine deficiency, which in severe cases can be fatal. Some dogs don't tolerate milk or other dairy products well and may experience vomiting and diarrhea. Raw egg whites fed in large amounts without the yolk binds biotin, making it unavailable to the body and resulting in a deficiency.
Ingredients and Seasonings
An unknown toxin in macadamia nuts can affect the nervous, muscular and digestive systems. Excessive salt leads to electrolyte imbalances, which can affect all systems. Sugary foods may cause obesity, diabetes or dental problems. Raw yeast dough can rise in the stomach and let off gasses, causing pain, obstruction or possible rupture. The artificial sweetener xylitol causes hypoglycemia, which leads to vomiting, weakness and collapse; high doses may lead to liver failure.
Chocolate contains caffeine and theobromine. Chocolate toxicity is dose-dependent and varies by the type of chocolate. Milk chocolate contains less of the toxic compounds, while baker's chocolate is high in them. White chocolate, which contains very little actual chocolate, is correspondingly very low in toxicity; a 10 lb. dog would need to eat 28 lbs. of white chocolate before showing signs of toxicity. The same dog would need to consume only 1 oz., or one square, of baker's chocolate before symptoms develop.
Additional Foods to Avoid
While healthy table scraps such as uneaten meats and vegetables might be fine for dogs, they should be offered only in moderation. Some table scraps can even be harmful. Fat trimmings can cause pancreatitis, and cooked bones may splinter and cause punctures or obstructions along the digestive tract. Moldy or spoiled food, as well as garbage, can cause digestive upset and may contain toxins that affect various organs.