Most dogs love food, and they’re especially attracted to what they see us eating. While sharing the occasional tidbit with your dog is fine, it’s important to be aware that some foods can be very dangerous to dogs. Take caution to make sure your dog never gets access to the foods below. Even if you don’t give him table scraps, your dog might eat something that’s hazardous to his health if he raids kitchen counters, cupboards and trash cans.
Avocados are toxic to a number of animals, including horses, rabbits, fish and mice. The toxic effects are due to the compound persin, an oil-soluble toxin found in specialized cells (idioblasts) within the avocado fruit, as well as in its skin. In some animals, persin causes damage to the heart muscle cells, leading to heart failure.
Raw bread dough made with live yeast can be hazardous if ingested by dogs. When raw dough is swallowed, the warm, moist environment of the stomach provides an ideal environment for the yeast to multiply, resulting in an expanding mass of dough in the stomach. Expansion of the stomach may be severe enough to decrease blood flow to the stomach wall, resulting in the death of tissue. Additionally, the expanding stomach may press on the diaphragm, resulting in breathing difficulty. Perhaps more importantly, as the yeast multiplies, it produces alcohols that can be absorbed, resulting in alcohol intoxication. In extreme cases, coma or seizures may occur and could lead to death from alcohol intoxication.
Chocolate intoxication is most commonly seen around certain holidays—like Easter, Christmas, Halloween and Valentine’s Day—but it can happen any time dogs have access to products that contain chocolate, such as chocolate candy, cookies, brownies, chocolate baking goods, cocoa powder and cocoa shell-based mulches. The rule of thumb with chocolate is “the darker it is, the more dangerous it is.” Dark baker’s chocolate has very high levels of methylxanthines, and plain, dry unsweetened cocoa powder contains the most concentrated levels of methylxanthines.
Ethanol (Also Known as Ethyl Alcohol, Grain Alcohol or Drinking Alcohol)
Dogs are far more sensitive to ethanol than humans are. Even ingesting a small amount of a product containing alcohol can cause significant intoxication. Dogs may be exposed to alcohol through drinking alcoholic drinks, such as beer, wine or mixed drinks (those with milk, like White Russians and “fortified” egg nog, are especially appealing to dogs), alcohol-containing elixirs and syrups, and raw yeast bread dough (please see the above section on bread dough).
Grapes and Raisins
Grapes and raisins have recently been associated with the development of kidney failure in dogs. Some dogs eat these fruits and experience no ill effects—but then eat them later on and become very ill. Death due to kidney failure may occur within three to four days, or long-term kidney disease may persist in dogs who survive the acute intoxication.
Cultivated hops used for brewing beer have been associated with potentially life-threatening signs in dogs who have ingested them. Both fresh and spent (cooked) hops have been implicated in poisoning dogs.
Although macadamia nut toxicosis is unlikely to be fatal in dogs, it can cause very uncomfortable symptoms that may persist for up to 48 hours. Affected dogs develop weakness in their rear legs, appear to be in pain, may have tremors and may develop a low grade fever.
A wide variety of molds grow on food. Some produce toxins called tremorgenic mycotoxins, which can cause serious or even life-threatening problems if ingested by dogs. Unfortunately, it’s not possible to determine whether a particular mold is producing tremorgenic mycotoxins, so the safest rule of thumb is to avoid feeding dogs moldy food. In other words, if you wouldn’t eat it, neither should your dog. Promptly remove any trash or moldy debris (road-kill, fallen walnuts or fruit, etc.) from your dog’s environment to prevent him from eating it.
Onions and Garlic
All close members of the onion family (shallots, onions, garlic, scallions, etc.) contain compounds that can damage dogs’ red blood cells if ingested in sufficient quantities. A rule of thumb is “the stronger it is, the more toxic it is.” Garlic tends to be more toxic than onions, on an ounce-for-ounce basis. While it’s uncommon for dogs to eat enough raw onions and garlic to cause serious problems, exposure to concentrated forms of onion or garlic, such as dehydrated onions, onion soup mix or garlic powder, may put dogs at risk of toxicosis. The damage to the red blood cells caused by onions and garlic generally doesn’t become apparent until three to five days after a dog eats these vegetables.
Xylitol is a non-caloric sweetener that is widely used in sugar-free gum, as well as in sugar-free baked products. In humans, xylitol does not affect blood sugar levels, but in dogs, ingestion of xylitol can lead to a rapid and severe drop in blood sugar levels. All dogs ingesting xylitol-containing products should be examined by a veterinarian immediately.