People usually land here after a dog steals a muffin, a cat licks a saucer, or a child drops something sweet on the floor—and the question is immediate: is this an emergency, or just a mess? With some human foods, timing matters. A few minutes can change the outcome.
Below are the everyday foods and ingredients most often linked with poisoning in pets, what tends to happen in the body, and the quickest, safest next steps if you think something has been eaten.
First: what to do if your pet eats something toxic
- Remove access (pick up leftovers, move the packet, check for wrappers).
- Work out what and how much (type of food, brand/ingredients, estimated amount, time eaten, your pet’s weight).
- Call your vet or an emergency vet straight away—don’t wait for symptoms.
- Do not induce vomiting unless a vet tells you to. For some toxins (including xylitol), signs can start quickly and home vomiting attempts can make things worse.7
Chocolate
Chocolate contains methylxanthines—mainly theobromine, and often caffeine—which pets (especially dogs) clear far more slowly than people. Darker chocolates and baking chocolate carry more of the toxins, so a smaller piece can do more harm.1, 8
Typical signs include vomiting, diarrhoea, restlessness, a fast or irregular heart rate, tremors and seizures. Severe poisoning can be fatal, particularly if treatment is delayed.1, 8
Grapes, raisins and sultanas
These can trigger acute kidney injury in dogs, and the toxic agent is still not fully understood. Risk is unpredictable: some dogs become very ill after only a few grapes, while others appear unaffected—so it’s treated as a no-safe-dose exposure.9, 2
Early vomiting and diarrhoea may be followed by lethargy, reduced appetite and changes in urination. Kidney damage can progress over the following days without prompt veterinary care.9
Onion, garlic, chives and leeks (Allium family)
Allium plants contain oxidant compounds that can damage red blood cells, leading to Heinz body haemolytic anaemia. Cats are generally more susceptible than dogs, and concentrated forms (powders, flakes, soup mixes) are a common cause.10, 4
Signs don’t always appear immediately. Anaemia may take days to show, with weakness, pale gums, rapid breathing, collapse, and sometimes dark urine. Both cooked and raw forms can be a problem.10
Avocado
Avocado contains persin and is risky for some species—particularly birds and certain livestock—where it has been linked with serious heart damage and death. Dogs seem relatively resistant to persin compared with birds, but avocado can still cause gastrointestinal upset, and the pit is a physical hazard that can obstruct the gut.5, 6
If you keep pet birds, treat avocado as strictly off-limits. Even small amounts have been associated with severe illness in caged birds.5
Xylitol (sweetener)
Xylitol is a sugar alcohol used in many “sugar-free” products (some gums, lollies, baked goods, and even certain toothpastes and medicines). In dogs, it can trigger a rapid insulin release causing dangerous hypoglycaemia, and in some cases severe liver injury.7
Signs can start within 30 minutes (sometimes later, depending on the product) and can include vomiting, weakness, wobbliness, seizures and collapse. Because the window is tight, don’t try home remedies—call a vet immediately.7, 3
Important correction: xylitol poisoning is well documented in dogs; it is not generally reported to cause the same hypoglycaemia or liver injury in cats.7
Alcohol
Alcohol is quickly absorbed and can cause rapid intoxication, vomiting, unsteadiness, low body temperature, metabolic disturbances, depressed breathing, coma and death. Sources aren’t limited to drinks—think raw dough that is fermenting, some medicines, and some household products.11
Caffeine
Caffeine is found in coffee, tea, energy drinks, cola, some supplements and medications. Pets are more sensitive than people, and concentrated sources (like caffeine tablets) are particularly dangerous. Signs can begin within a couple of hours and may include restlessness, panting, vomiting, tremors, seizures and abnormal heart rhythms.12, 4
Macadamia nuts
In dogs, macadamia nuts can cause a distinctive syndrome: weakness (often of the hind limbs), vomiting, wobbliness and sometimes tremors or fever. The exact toxin is unknown, but most cases improve with supportive care over a day or two—still, your vet should guide the response, especially if signs are marked or your dog has other health problems.13
Final thoughts
Most pet food scares come from ordinary moments: a dropped snack, a festive plate left low, a curious nose in a handbag. The safest pattern is simple—keep high-risk foods out of reach, don’t offer “just a taste”, and treat any suspected ingestion as time-sensitive. If you’re unsure, ring your vet and describe exactly what happened.
References
- U.S. Food & Drug Administration (FDA) — Leave Chocolate Out of Rover’s Celebrations
- Cornell University College of Veterinary Medicine — Grape and raisin toxicity
- University Veterinary Teaching Hospital Sydney — Dangerous substances (dangerous foods)
- Agriculture Victoria (Animal Welfare Victoria) — Human foods to avoid for cats and dogs
- Merck Veterinary Manual (Pet Owner Version) — Food hazards (includes avocado)
- Merck Veterinary Manual — Avocado (Persea spp) toxicosis in animals
- Merck Veterinary Manual — Xylitol toxicosis in dogs
- RSPCA Victoria — Easter chocolate a big pet hazard
- Vetwell Veterinary Practices — Grape & raisin toxicity (Australia)
- Merck Veterinary Manual — Garlic and onion (Allium spp) toxicosis in animals
- Merck Veterinary Manual — Toxicoses from alcohols in animals
- VCA Animal Hospitals — Caffeine toxicity in pets
- Merck Veterinary Manual — Macadamia nut toxicosis in dogs
Veterinary Advisor, Veterinarian London Area, United Kingdom