Foods Toxic to Dogs: A Veterinarian-Backed List by Severity
The internet says chocolate kills dogs. It can, but a single milk chocolate chip won’t. The internet says grapes are toxic to every dog. They can be, but we still don’t know why some dogs tolerate them and others end up in kidney failure. This article ranks foods toxic to dogs by actual emergency risk, cites dose thresholds where veterinary science has them, and tells you when to call ASPCA Poison Control versus when to just monitor your dog.
This list is for dog owners who want the real information without the panic or the vagueness. I’ve fostered more than forty dogs. I’ve called Poison Control twice — once for a terrier who ate a bag of dark chocolate, once for a hound who got into sugar-free gum. Both times, the dose mattered more than the food itself.
1. Xylitol (Artificial Sweetener) — Emergency Every Time
Xylitol is the toxin most dog owners don’t know to look for until it’s too late. It’s in sugar-free gum, certain peanut butters, baked goods, toothpaste, and mouthwash. In dogs, xylitol triggers rapid insulin release, which crashes blood sugar to dangerous levels within 30 minutes. Larger doses damage the liver.
Threshold: As little as 0.1 grams per kilogram of body weight can cause hypoglycemia. One stick of xylitol gum can be toxic to a 20-pound dog.
Symptoms: Vomiting, lethargy, loss of coordination, seizures. Liver failure can occur 12–24 hours later even if initial symptoms resolve.
What to do: Call ASPCA Poison Control (888-426-4435) or your emergency vet immediately. Do not wait to see if symptoms develop.
Source: ASPCA Animal Poison Control Center; AVMA toxicology guidelines
2. Chocolate — Dose and Type Matter
Dark chocolate and baking chocolate are dangerous. Milk chocolate and white chocolate are less so, but still risky in larger amounts. The toxic compound is theobromine, which dogs metabolize slowly.
Threshold: 10–20 mg/kg body weight can cause mild symptoms (vomiting, diarrhea). 20+ mg/kg is a medical emergency (tremors, elevated heart rate, seizures). A 10-pound dog eating a bar of dark chocolate is at serious risk. That same dog eating one Hershey’s Kiss is very unlikely to be affected.
Symptoms: Vomiting, diarrhea, restlessness, elevated heart rate, tremors, seizures in severe cases.
What to do: Call Poison Control with the type and amount of chocolate eaten and your dog’s weight. They’ll calculate toxicity and tell you whether to go to the ER or monitor at home.
Source: ASPCA APCC data; veterinary toxicology consensus
If your dog is a known counter-surfer, dog proofing your kitchen covers prevention strategies that work.
3. Grapes and Raisins — Unpredictable and Potentially Severe
Here’s what we know: grapes and raisins can cause acute kidney injury in dogs. Here’s what we don’t know: why some dogs tolerate them and others don’t, or what compound is responsible. The ASPCA has documented cases where a handful of raisins caused kidney failure and cases where a dog ate a pound of grapes with no symptoms.
Threshold: Unknown. Even small amounts are treated as a potential risk.
Symptoms: Vomiting, diarrhea, lethargy, decreased appetite. Kidney injury typically develops 48–72 hours after ingestion, so delayed symptoms don’t mean your dog is safe.
What to do: Call your vet or Poison Control immediately, even if your dog seems fine. Do not adopt a “wait and see” approach.
Source: ASPCA APCC case reports; Eubig et al., Journal of Veterinary Diagnostic Investigation, 2005
4. Onions and Garlic (All Forms) — Slow Damage, Clear Risk
Onions and garlic contain thiosulfate, which damages red blood cells and causes hemolytic anemia. The danger is cumulative and delayed — symptoms may not appear for 1–5 days, which means owners often don’t connect the illness to the food.
Threshold: Generally 15–30 grams per kilogram of body weight. A 50-pound dog would need to eat roughly a cup of raw onion to show clinical signs. Garlic is more concentrated than onion. Garlic powder is the most concentrated form and should be avoided entirely.
Symptoms: Vomiting, diarrhea, lethargy, pale gums, weakness. Anemia develops over days.
What to do: If your dog ate a significant amount (not a tiny piece of onion from your sandwich), call your vet. They may recommend bloodwork to monitor red blood cell count.
Source: ASPCA APCC; veterinary toxicology texts
5. Macadamia Nuts — Temporary but Dramatic
Macadamia nuts cause weakness, tremors, and hyperthermia in dogs. The toxic compound is still unknown, but the symptoms are consistent and documented well enough that the ASPCA lists them as a moderate-risk toxin.
Threshold: Roughly 0.7 grams per kilogram of body weight. 10–24 nuts can affect a 20-pound dog.
Symptoms: Weakness (especially in hind legs), tremors, vomiting, hyperthermia, lethargy. Most dogs recover fully within 24–48 hours.
What to do: Call your vet. Most cases don’t require emergency treatment, but your vet may want to monitor symptoms or provide supportive care.
Source: ASPCA APCC; veterinary toxicology literature
6. Alcohol (Including Raw Bread Dough) — Rapid CNS Depression
Ethanol affects dogs the same way it affects humans, but dogs are much smaller and metabolize it differently. Unattended cocktails, fermented foods, and raw bread dough (which ferments in the stomach) are all risks.
Threshold: 0.8 grams per kilogram can cause intoxication. 3+ grams per kilogram can cause respiratory depression.
Symptoms: Vomiting, disorientation, lethargy, hypothermia, difficulty breathing, seizures.
What to do: Emergency vet visit. Alcohol poisoning can be fatal.
Source: ASPCA APCC; AVMA toxicology guidelines
7. Avocado — Low Risk, Mostly Overhyped
Avocado contains persin, a fungicidal toxin that’s dangerous to birds and horses but only mildly problematic for dogs. A dog who eats a few bites of avocado flesh is unlikely to need emergency care. The pit is a choking hazard, not a toxicity concern.
Threshold: Large amounts can cause vomiting, diarrhea, or pancreatitis (due to fat content more than persin).
Symptoms: GI upset. Rarely, pancreatitis.
What to do: Monitor your dog. Call your vet if symptoms persist or worsen.
Source: ASPCA APCC; veterinary toxicology consensus
Honest take: Avocado is on every toxic foods list, but it’s low-risk compared to xylitol, chocolate, or grapes. If your dog ate guacamole, watch them. If your dog ate xylitol gum, go to the ER.
How We Ranked These
This list is organized by emergency risk, not alphabetical order. Xylitol and chocolate are at the top because they require immediate veterinary intervention. Avocado is at the bottom because it rarely causes serious harm. Every threshold cited comes from ASPCA Animal Poison Control Center data, peer-reviewed veterinary toxicology literature, or AVMA consensus guidelines. When the science is unclear (grapes), we say so.
Frequently Asked Questions
What should I do if my dog eats something toxic?
Call ASPCA Poison Control (888-426-4435) or Pet Poison Helpline (855-764-7661) immediately. Have your dog’s weight, the name of the food, and the estimated amount ready. Do not wait to see if symptoms develop — some toxins cause delayed damage.
Are grapes really toxic to all dogs?
Grapes can cause acute kidney injury in some dogs, but the toxic compound is still unknown and toxicity is unpredictable. Some dogs tolerate grapes with no symptoms; others develop kidney failure after eating a small amount. The safest approach is to avoid grapes and raisins entirely.
How much chocolate is dangerous for a 50-pound dog?
It depends on the type of chocolate. A 50-pound dog would need to eat roughly 10 ounces of milk chocolate or 1 ounce of baking chocolate to reach the toxic threshold. Dark chocolate falls in between. Call Poison Control with the specific type and amount — they calculate toxicity based on your dog’s weight.
Can dogs eat peanut butter?
Most peanut butter is safe for dogs, but some brands contain xylitol, which is extremely toxic. Always check the ingredient label before giving your dog peanut butter. If it contains xylitol, do not give it to your dog.
Toxicity is dose-dependent. A single chocolate chip is not the same as a chocolate cake. A sliver of onion is not the same as a bowl of French onion soup. If your dog ate something on this list, call Poison Control with the specifics — they’ll tell you whether you need to go to the ER or just keep an eye on your dog. For ongoing training to prevent counter-surfing and food theft, teaching leave it command covers the foundation behavior that keeps most accidental ingestions from happening in the first place.