Common Myths About What Pets Can and Cannot Eat

The image of a cat lapping up a saucer of milk is deeply embedded in popular culture, but it doesn't reflect feline biology. After kittenhood, most cats stop producing sufficient lactase — the enzyme needed to digest lactose — meaning cow's milk is poorly tolerated. Small amounts may not cause immediate crisis, but repeated exposure can lead to chronic gastrointestinal issues. If you want to offer your cat a liquid treat, plain water or specially formulated cat milk (lactose-reduced) are far safer options.

The exact compound in grapes and raisins responsible for toxicity in dogs has not been fully identified, which makes this particularly concerning — there's no safe known dose. Some dogs have experienced kidney failure after eating just a handful of raisins. Symptoms can include vomiting, lethargy, and decreased urination. Because individual sensitivity varies and the mechanism isn't fully understood, veterinarians universally advise keeping grapes and raisins completely away from dogs. This is one myth where the stakes are high enough that no experimentation is worth the risk.

Cooking changes the structural integrity of bones, making them brittle. When a dog chews a cooked bone, it can fracture into sharp shards capable of lacerating the mouth, esophagus, stomach, or intestines. Raw bones carry their own risks — including bacterial contamination and dental fractures — and veterinary opinion on raw bones is divided. The safest approach is to discuss appropriate chew options, including commercially designed dental chews, with your veterinarian rather than relying on kitchen scraps.

Compounds called thiosulfates in onions and garlic damage red blood cells in dogs and cats, leading to a condition called hemolytic anemia, where the body destroys its own red blood cells faster than it can replace them. This applies to all forms: raw, cooked, powdered, or dehydrated. Powdered onion or garlic found in soups, sauces, or seasoning blends can be especially concentrated and dangerous. Cats are generally more sensitive than dogs. Symptoms — weakness, pale gums, reduced appetite — may not appear for several days after ingestion, making this toxin particularly deceptive.

Carrots, green beans, and blueberries are commonly cited as dog-safe snacks, and in small, appropriate quantities they can offer some nutritional value or enrichment. However, the category of "vegetables" is broad, and several plants in that group are harmful. Leeks and chives share the same toxic compounds as onions and garlic. Avocado contains persin, which can cause vomiting and diarrhea in dogs. For cats — obligate carnivores — vegetables offer very limited nutritional value and some may cause digestive upset. Treats of any kind should represent no more than 10% of a pet's daily caloric intake, and new foods should always be introduced one at a time.

Xylitol is a sugar alcohol used as a sweetener in hundreds of products beyond candy, including some brands of peanut butter, chewing gum, mouthwash, vitamins, and even certain medications. In dogs, xylitol triggers a rapid release of insulin that can lead to life-threatening hypoglycemia (low blood sugar) and, in larger doses, liver failure. Symptoms can appear within 15 to 30 minutes of ingestion. Because peanut butter is commonly used as a treat or medication delivery vehicle for dogs, owners should always read ingredient labels carefully before purchasing. Xylitol does not appear to cause the same insulin response in cats, though it is still best avoided.