Pooch food alert!

The following article is based on National Geographic Channel’s proven studies and something that dog owners should keep in mind when feeding your well-loved dogs.

Canine Taboos: Some seemingly innocuous foods can be lethal for dogs.

This year, pet food contaminated with melamine caused kidney failure and death in dogs. But unbeknownst to many dog owners, ordinary human foods—even in small quantities—can be just as lethal.

The list of potentially hazardous everyday human foods is growing. In 2006 the American Society for the Prevention of Cruelty to Animals (ASPCA) received approximately 116,000 calls regarding poisoning. Nearly 200 asked about xylitol, a popular sugar substitute found in baked goods, candy, and gum. And for breeds like 45-pound (20 kilograms) shar-pei Mako (featured in this interactive), even a small piece of chocolate could be perilous.

Check out the top foods your pooch shouldn’t eat:

Alcohol

Alcohol depresses brain function in dogs and can send them into a coma. It can cause further damage by turning their blood acidic.

Dogs are not equipped with the protective enzymes that allow humans to imbibe reasonable amounts of alcohol without harm. And because most dogs are smaller than humans and are more sensitive to alcohol, it does not take a lot to cause serious problems. How much depends on the size of the dog and the type of alcohol it consumes.

So no piña coladas for Fido—not for fun and not by accident with party leftovers.

Onion
Their damage to canine hemoglobin is cumulative, so small tastes over time can be worse than wolfing down the whole bulb.

In fact, 600 to 800 grams (21 to 28 ounces) of raw onion eaten all at once, or 150 grams (5.3 ounces) eaten over several days, can induce anemia.

Anything onion, like anything garlic, also contains the thiosulphate compound, and dogs lack the enzyme to digest it.

Grapes
Toxicologists have found that grapes and raisins can cause acute renal and kidney failure.

Though there is ongoing research, some suspect the cause may be a compound soluble in water indigestible to dogs or a possible fungal toxin.

However, toxicologists do know that as few as ten raisins or grapes, anywhere from nine ounces (255 grams) to two pounds (0.9 kilograms), could be fatal.

Coffee
The caffeine in a cup of java is a methylxanthine compound that binds to receptors on cell surfaces, precluding the normal compounds from attaching there.

Caffeine in any form—coffee, tea, soda, or chocolate—can increase a dog’s heart rate, produce an irregular heartbeat, and trigger seizures. It can also cause severe gastrointestinal problems.

Chocolate
The chemical theobromine can be fatal. Just three ounces (85 grams) of dark chocolate or seven (198 grams) of milk chocolate can bring on vomiting in a 50-pound (23 kilograms) dog.

Chocolate also contains the methylxanthine compound, making the combination of theobromine and methylxanthine a dangerous and deadly combination for our best friends. Dogs don’t metabolize and excrete theobromine as fast as humans, causing toxic buildup in the blood.

Signs of chocolate toxicity occur within hours—they include vomiting, diarrhea, increased heart rate, rapid breathing, tremors, seizures, and coma.

Yeast
Like alcohol, ingestion of yeast can cause fatal damage. Active yeast found in raw bread dough releases alcohol as it grows.

Yeast enjoys moist, warm environments—like a dog’s stomach. The expanding dough can prevent blood from flowing to the heart, distending the abdomen.

Macadamia Nuts
Experts have yet to determine why just a few of these nuts can produce tremors, even temporary paralysis, in a dog’s hind legs.

High phosphorous content in nuts in general can cause kidney stones.

It doesn’t take much—four or five nuts and a ten-pound (4.5 kilograms) dog can show signs of poison.

Garlic
Garlic, in any form, breaks down a dog’s red blood cells, and large amounts over time can lead to anemia and possible kidney failure from leaking hemoglobin.

The reason: dogs don’t have the necessary enzyme to properly breakdown the compound thiosulphate.

According to ASPCA, if a dog eats 0.5 percent of its body weight in garlic, it can show signs of poison. In other words, five grams (0.18 ounces) of garlic per kilogram (2.2 pounds), or two grams (0.07 ounces) of garlic per pound can mean an emergency trip to the vet.