* Alcoholic beverages. Because alcohol can be fatal to dogs, no amount of alcoholic beverage is safe… yes; even beer should be off limits.
* Chocolate is toxic to canines. The darker the chocolate, the more harmful. The methylxanthines (caffeine and theobromine) in chocolate can cause a dog to vomit, have diarrhea, experience rapid, irregular heart beat, have increased urination, and experience muscle tremors and seizures. The effects can be serious. Death from chocolate toxicity can occur with 24 hours.
* Coffee, tea and cola are people-food. They contain caffeine, a methylxanthine also found in chocolate. The signs of toxicity include rapid heart beat, hyperexcitability, tremors, and seizures.
* Macadamia nuts can temporarily cause muscle weakness, often in the hind legs. Other signs include vomiting, fever, and abdominal pain. The mechanism of the toxicity is unknown. Affected dogs recover with no treatment and no long-term effects.
* Onions and garlic have a chemical that damages red blood cells in dogs and can cause anemia. Even one small whole onion can cause death. So be particularly careful when disposing of left-overs that contain a significant amount of onions, such as pizza or Chinese take-out. The small amounts of onion and garlic powder used in pet foods is safe and well below the toxic levels.
* Raisins and grapes seem like fun toys to a dog. But they can cause vomiting, diarrhea, and kidney failure. The minimum safe amount is not known, so keep these foods well out of reach of curious muzzles.
* Sugarless gums and candies are certainly sweet, but the sugar substitute xylitol can cause a rapid drop in your dog's blood sugar.
* Moldy or spoiled food and garbage should stay safely in the trash. They can contain multiple toxins causing vomiting, diarrhea, and damage to internal organs.
* Yeast dough, like the kind used in making bread or desserts, is designed to expand. If swallowed by an unsuspecting canine, it can expand and produce gas in the digestive system, causing pain and possibly rupture of the stomach or intestines.
* Medications such as Ibuprofen, Tylenol, and Naproxen may give you some relief, but painkillers and other common medications can be deadly to your dog. Keep all prescription and over-the-counter drugs - including painkillers, ant-inflammatory drugs, cold medicines, diet pills, antidepressants, anti-cancer drugs, and vitamins - in closed cabinets out of your pets' reach. Never give your dog medication unless directed by a vet.
* Plants are pretty but possibly deadly for your dog. Many common yard and houseplants can be poisonous, including lily, daffodil, oleander, rhododendron, azalea, yew, foxglove, rhubarb leaves, and cycads.
Alcoholic beverages Can cause intoxication, coma, and death.
Baby food Can contain onion powder, which can be toxic to cats. (Please see onion below.) Can also result in nutritional deficiencies, if fed in large amounts.
Bones from fish, poultry, or other meat sources Can cause obstruction or laceration of the digestive system.
Canned tuna (for human consumption) Large amounts can cause malnutrition, since it lacks proper levels of vitamins and minerals.
Chocolate, coffee, tea, and other caffeine Contain caffeine, theobromine, or theophylline, which can be toxic and affect the heart and nervous system.
Citrus oil extracts Can cause vomiting.
Dog food If accidental ingestion, will not cause a problem; if fed repeatedly, may result in malnutrition and diseases affecting the heart.
Fat trimmings Can cause pancreatitis.
Grapes and raisins Contain an unknown toxin, which can damage the kidneys.
Human vitamin supplements containing iron Can damage the lining of the digestive system and be toxic to the other organs including the liver and kidneys.
Large amounts of liver Can cause Vitamin A toxicity, which affects muscles and bones.
Macadamia nuts Contain an unknown toxin, which can affect the digestive and nervous systems and muscle.
Marijuana Can depress the nervous system, cause vomiting, and changes in the heart rate.
Milk and other dairy products Some adult cats and dogs do not have sufficient amounts of the enzyme lactase, which breaks down the lactose in milk. This can result in diarrhea. Lactose-free milk products are available for cats.
Moldy or spoiled food, garbage Can contain multiple toxins causing vomiting and diarrhea and can also affect other organs.
Mushrooms Can contain toxins, which may affect multiple systems in the body, cause shock, and result in death.
Onions and garlic (raw, cooked, or powder) Contain sulfoxides and disulfides, which can damage red blood cells and cause anemia. Cats are more susceptible than dogs. Garlic is less toxic than onions.
Persimmons Seeds can cause intestinal obstruction and enteritis.
Potato, rhubarb, and tomato leaves; potato and tomato stems Contain oxalates, which can affect the digestive, nervous, and urinary systems. This is more of a problem in livestock.
Raw eggs Contain an enzyme called avidin, which decreases the absorption of biotin (a B vitamin). This can lead to skin and hair coat problems. Raw eggs may also contain Salmonella.
Raw fish Can result in a thiamine (a B vitamin) deficiency leading to loss of appetite, seizures, and in severe cases, death. More common if raw fish is fed regularly.
Salt If eaten in large quantities it may lead to electrolyte imbalances.
String Can become trapped in the digestive system; called a "string foreign body."
Sugary foods Can lead to obesity, dental problems, and possibly diabetes mellitus.
Table scraps (in large amounts) Table scraps are not nutritionally balanced. They should never be more than 10% of the diet. Fat should be trimmed from meat; bones should not be fed.
Tobacco Contains nicotine, which affects the digestive and nervous systems. Can result in rapid heart beat, collapse, coma, and death.
Yeast dough Can expand and produce gas in the digestive system, causing pain and possible rupture of the stomach or intestines.