What Human Foods Are Bad For Dogs?
I get asked this a lot by training clients, and it’s absolutely true that there are a bunch of food and household items that are fine for people but unsafe or even dangerous for dogs. I’m not a vet, but I’ve listened very carefully to my own over the years, and I’ve done my homework on each item to help sort between myths, fearmongering, and real threats to dogs. So this is the list we use with our own dogs.
Chocolate. Theobromine is a chemical found in cocoa beans, and it's quite toxic to dogs. However, be aware that the amount of actual cocoa in many commercial chocolate products (like cheap milk chocolate) is actually quite low, so small amounts of something like Hershey’s Kisses would be generally harmless, especially to a medium or large dog. But the darker the chocolate, the more theobromine it has, so things like fancy dark chocolate or baking chocolate can be harmful in much smaller amounts.
Grapes and raisins. The mechanism of toxicity is still under study, and not all dogs seem to be susceptible, but it has been confirmed repeatedly that some dogs can experience acute renal failure after just a few grapes or raisins.
Macadamia nuts. As with grapes, the mechanism for this toxicity isn't known, and it appears to vary greatly from dog to dog, but it's a confirmed problem. Symptoms include vomiting, lethargy, and shaking. Most dogs survive macadamia poisoning, but it's obviously best not to gamble.
Antifreeze. Obviously, antifreeze is poisonous, but what's not obvious is that it's sweet tasting. Many dogs will lick it up spilled antifreeze if, for example, it leaks out of your car onto the driveway. Very small amounts of antifreeze can be fatal, so take great care with this one. One thing that can help you identify it if you find a leak under your car is that it smells sweet (people often compare the smell to maple syrup).
Alliums (onions, garlic, leeks, chives, etc). Allium plants contain a set of chemicals (sulfoxides and sulfides) that can cause anemia in dogs. As with theobromine in chocolate, the danger is dosage-dependent, so a little bit of onion or garlic shouldn't cause a problem. However, you do want to keep your dog from eating large amounts of onions, and most veterinary organizations will encourage you to stay away from all alliums entirely.
Avocado. There is some debate surrounding the toxicity of avocados. The pits are definitely toxic to many mammals, as are the leaves of the plant, and the meat of at least some varieties are toxic to at least some dogs. If you want to do your research on what varieties of avocado are safe, go for it, but don't just give avocado willy-nilly to your pup.
Salt. Dogs' kidneys are generally more sensitive to damage than ours, so be careful that your dog doesn't get a chance to ingest large amounts of salt. Many human foods are really high in sodium, so really keep an eye on this one. For example, if you want to give your dog peanut butter, get the one that’s just peanuts, with no added salt or sugar. He’ll still love it!
Modeling dough. Commercial products like Play-doh contain quite a bit of salt, and some homemade varieties include tons of salt and cream of tartar, which is also be toxic to dogs in high doses, so “non-toxic" and homemade modeling dough that’s perfectly safe for kids can actually be quite dangerous to dogs.
Caffeine. Dogs can be very sensitive to caffeine, so be sure your dog doesn't get a chance to ingest anything with a significant quantity of caffeine in it.
Alcohol. It's obvious that alcohol isn't for dogs, but what's not obvious is that many dogs like the taste of beer and of some sweet liquors and will drink them if they're spilled or if glasses are left within reach. A relatively small amount of alcohol can be dangerous for dogs, so don't play around. And no, it's not funny when a dog drinks beer and staggers around.
Xylitol. Xylitol is an artificial sweetener found in some human foods and is frequently the sweetener in sugar-free chewing gums. It is very poisonous to dogs. Also, xylitol has also been showing up in some “health foods.” For example, a couple of years ago, I found an “all natural” peanut butter on the shelf of a fancypants market that had xylitol, which was mentioned nowhere but at the bottom of the ingredient list.
Corn cobs. Corn is sweet, and the cobs frequently still have some butter and salt on them when we finish with them and throw them away. Lots of people let their dogs eat corn cobs and don’t have any problems, but old vet was an ER surgeon, and she told us they were one of the most common causes of intestinal obstructions requiring surgery that she saw, so we never give our dogs corn cobs.
Human pharmaceuticals. Human and canine physiology are quite similar, and many medicines that work for us are also used for dogs—typically in smaller doses since their bodies are smaller. But even medicines that might be safe for a dog in the right dosage are almost certainly an overdose if he swallows even one or two human pills. Also, some human meds have sweet buffered coatings that may tempt a dog if the pills are left in his reach. Lastly, there are some human medicines that are toxic to dogs even in tiny quantities. The lesson here is to keep all human meds out of the reach of your dog and never to give a dog human medicine unless it is specifically cleared by your dog's vet.
Fat. Fat is, obviously, an important part of a dog's diet. Dogs need lots of good fats. However, a large quantity of fat ingested quickly can cause diarrhea or vomiting, and if a dog gets too much fat in a short period of time, he can develop a condition called pancreatitis. Acute, severe pancreatitis can be fatal if left untreated. Symptoms of acute pancreatitis include vomiting, diarrhea, distended abdomen, hunching up, lethargy, and fever. If your dog eats a large amount of fat and seems to be feeling ill afterwards, call your vet sooner rather than later.
Cooked bone. We don't feed our dogs a raw diet, but many people who do give their dogs raw bones as part of the feeding protocol. Dogs seem to be able to break up and properly digest raw bones—though there are some precautions raw feeders take that you'll want to read about if you go in that direction with your dogs. However, cooked bones are another matter entirely. A bone that's been heated will splinter when it's chewed, and those splinters can perforate a dog's gastrointestinal tract if they're swallowed. They also can cause obstructions. Both of those problems can be fatal, so keep cooked bones away from your dog, and call the vet right away if your dog gets into any cooked bones.