The ASPCA Animal Poison Control Center receives roughly 400,000 calls a year. The Pet Poison Helpline receives another 200,000. Together, that is roughly 1,500 calls a day from panicked pet owners in North America, and the distribution of what those calls are about is remarkably consistent year over year. The top ten categories account for about 80% of all calls. If you memorise this article, you will recognise roughly 80% of the toxic exposures your pet is ever likely to encounter. This is the practical list, the dose thresholds, the symptoms, the home first response, and the four mistakes that turn a preventable exposure into a fatal one.
Foods
Chocolate. I covered this in detail in the dedicated chocolate article, but the headline is: dark chocolate and baking chocolate are the most dangerous (high theobromine), milk chocolate is moderately dangerous, white chocolate is essentially non-toxic. Toxic dose for dogs: roughly 100 mg of theobromine per kg of body weight for mild signs, 200 mg/kg for severe signs, 250 mg/kg for seizures. A 10 kg dog that eats 50 grams of dark chocolate (a small bar's worth) is in serious trouble. The symptoms progress from vomiting and restlessness to tremors to seizures to cardiac arrhythmias. The home response: call the vet immediately, do not induce vomiting unless instructed, save the wrapper so the vet can calculate the dose.
Xylitol (birch sugar). A sugar alcohol used in sugar-free gum, sugar-free candy, sugar-free baked goods, peanut butter, and some toothpastes and mouthwashes. In dogs, xylitol causes a massive insulin release, which produces hypoglycaemia within 10 to 60 minutes. The toxic dose is roughly 0.1 g/kg. A 10 kg dog that eats 3 pieces of sugar-free gum is at risk. The hypoglycaemia can cause weakness, ataxia, seizures, and coma. Xylitol can also cause hepatic failure in dogs at higher doses, presenting 24 to 48 hours later. The home response: this is a true emergency. Get the dog to a vet immediately. Do not wait for symptoms.
Grapes and raisins. Cause acute kidney injury in dogs through a mechanism that is still not fully understood. Some dogs appear to be highly sensitive; others seem to tolerate small amounts. The toxic dose is not predictable. The safe dose is zero. Symptoms: vomiting within 24 hours, lethargy, decreased appetite, increased thirst, decreased or absent urination, and progressive kidney failure over 3 to 5 days. Cats are also at risk. The home response: if the dog has eaten more than a small amount, get to the vet for decontamination and 48 hours of IV fluids. Aggressive fluid therapy within the first 24 hours dramatically improves the prognosis.
Onions, garlic, chives, leeks (the Allium family). Contain N-propyl disulfide, which causes oxidative damage to red blood cells (Heinz body anemia) in both dogs and cats. Cats are particularly sensitive. Toxic dose for dogs: roughly 5 g/kg of onion; for cats, much less. Symptoms: vomiting, diarrhoea, lethargy, pale or jaundiced gums, dark-coloured urine, increased heart and respiratory rate. Onset is delayed, usually 3 to 5 days. The home response: if a large amount was eaten recently, get to the vet. For small exposures, monitor for anemia signs over the next week.
Macadamia nuts. Cause a specific syndrome in dogs (macadamia nut toxicosis) with weakness, vomiting, ataxia, hyperthermia, and tremors. The mechanism is not fully understood. Toxic dose: roughly 2 g/kg. Onset within 12 hours. Symptoms usually resolve within 24 to 48 hours with supportive care. The home response: monitor and call the vet. Most cases are mild.
Avocado. Contains persin, which can cause vomiting and diarrhoea in dogs and is more toxic to birds and small pets. For dogs, the main concern is the pit (choking, foreign body obstruction) and the high fat content (pancreatitis risk in sensitive dogs). The home response: monitor for vomiting, watch for signs of obstruction if a pit was eaten.
Raw bread dough. The yeast in raw bread dough continues to ferment in the warm, moist environment of the stomach, producing ethanol and carbon dioxide. The ethanol causes alcohol toxicosis (vomiting, ataxia, hypothermia, hypoglycemia, respiratory depression). The expanding dough can also cause gastric dilatation. The home response: get to the vet for supportive care. Do not induce vomiting at home because of the risk of the dough expanding in the stomach.
Fatty foods (butter, bacon, fried foods, fatty trimmings). Not directly toxic, but a high-fat meal can trigger pancreatitis in susceptible dogs. Symptoms: vomiting, abdominal pain, lethargy, anorexia, dehydration. Onset 1 to 3 days after the meal. The home response: withhold food for 12 to 24 hours (water is OK), monitor for symptoms, and call the vet if vomiting or pain develops.
Medications
Acetaminophen (Tylenol). Highly toxic to cats, moderately toxic to dogs. Cats cannot metabolise it through glucuronidation, so even a single regular-strength tablet can be fatal. The mechanism is methemoglobinemia (the blood cannot carry oxygen) and hepatic necrosis. Symptoms in cats: vomiting, lethargy, brown or chocolate-coloured gums, facial swelling, respiratory distress, death. Symptoms in dogs: hepatic failure at high doses. The home response: emergency vet visit. There is an antidote (N-acetylcysteine) that must be given within the first 8 to 12 hours.
Ibuprofen and naproxen (Advil, Aleve). NSAIDs that cause GI ulceration and kidney failure in both dogs and cats. Cats are particularly sensitive. Toxic dose for dogs: 50 mg/kg for GI signs, 100 mg/kg for kidney failure. A 10 kg dog that eats 3 to 4 ibuprofen tablets is at risk. Symptoms: vomiting (often with blood), anorexia, abdominal pain, lethargy, dark or black stools. The home response: emergency vet visit, particularly if a large amount was eaten.
Pseudoephedrine and other decongestants. Stimulant toxicity. Symptoms: agitation, hyperactivity, tremors, seizures, hyperthermia, tachycardia. Toxic dose is low. The home response: emergency vet visit.
Selective serotonin reuptake inhibitors (SSRIs like Prozac, Zoloft, Lexapro). Cause serotonin syndrome. Symptoms: agitation, tremors, hyperthermia, tachycardia, seizures. Toxic dose is moderate. The home response: emergency vet visit. The vet will manage with cyproheptadine, supportive care, and sometimes lipid emulsion therapy.
Vitamin D analogues (calcipotriene, calcitriol). Found in psoriasis creams, some rodent baits (cholecalciferol), and some supplements. Cause hypercalcemia, soft tissue mineralisation, and acute kidney injury. Symptoms: vomiting, lethargy, increased thirst, kidney failure. Onset 12 to 36 hours, can be delayed. The home response: emergency vet visit. Treatment is prolonged and expensive.
Household products
Ethylene glycol (antifreeze). Highly toxic to dogs and cats. Causes severe acute kidney injury. The toxic dose is small (1.4 mL/kg for cats, 4.4 mL/kg for dogs). Antifreeze is sweet-tasting, which attracts animals. Symptoms occur in three stages: neurological (30 minutes to 12 hours, looks drunk), cardiopulmonary (12 to 24 hours, rapid breathing, tachycardia), and renal (24 to 72 hours, kidney failure with no urine production). The home response: emergency vet visit. There is an antidote (4-methylpyrazole or ethanol) that must be given within the first 8 hours. Antifreeze exposures have a very narrow window.
Bleach, detergents, drain cleaners, oven cleaners. Caustic or corrosive. Cause oral, esophageal, and gastric burns. Symptoms: drooling, oral pain, vomiting (sometimes with blood), difficulty swallowing, abdominal pain. The home response: do not induce vomiting (the caustic material will damage the esophagus again on the way up). Rinse the mouth with water and get to the vet. Milk or water can be offered to dilute the material.
Concentrated essential oils (tea tree, peppermint, wintergreen, citrus, pine). Toxic to both dogs and cats, with cats being more sensitive due to their reduced glucuronidation capacity. Tea tree oil is particularly toxic — a few drops can cause severe toxicity in cats. Symptoms: drooling, vomiting, ataxia, tremors, hypothermia, liver failure. The home response: emergency vet visit. Decontamination with skin washing if topical exposure, supportive care.
Plants
Lilies (Lilium and Hemerocallis species). Highly toxic to cats, even in tiny amounts. Cause acute kidney injury. Pollen, leaves, flowers, and even the water in a vase can be toxic. The toxic dose is essentially the smallest lick. Symptoms: vomiting within hours, progressing to kidney failure within 24 to 72 hours. The home response: this is a true emergency for any cat with any potential lily exposure. Aggressive IV fluids for 48 to 72 hours is the standard. The prognosis depends on how quickly the fluids are started.
Sago palm. All parts of the plant are toxic, especially the seeds. Cause liver failure. Symptoms: vomiting (often with blood), jaundice, lethargy, seizures, liver failure. The home response: emergency vet visit. Aggressive decontamination and supportive care.
Oleander, foxglove, lily of the valley, kalanchoe, yew. Contain cardiac glycosides. Cause cardiac arrhythmias, bradycardia or tachycardia, GI signs, collapse, death. The home response: emergency vet visit.
Dieffenbachia, philodendron, pothos, peace lily (the Araceae family). Contain calcium oxalate crystals. Cause oral irritation, drooling, oral pain, swelling, vomiting. Usually not life-threatening but very uncomfortable. The home response: rinse the mouth, offer milk or water, call the vet.
Rodenticides
The category is dangerous because the baits are designed to be tasty. There are several different active ingredients, and the treatment depends on which one was eaten.
Anticoagulant rodenticides (brodifacoum, bromadiolone, diphacinone, warfarin). Block vitamin K-dependent clotting factors. Symptoms: bleeding (external or internal), pale gums, weakness, coughing, lameness, sudden death. Onset 3 to 7 days after exposure. The home response: emergency vet visit. Treatment is vitamin K1 for 3 to 4 weeks. If a large amount was eaten, vitamin K1 is started prophylactically.
Cholecalciferol (vitamin D3) rodenticides. Cause hypercalcemia and acute kidney injury. Symptoms: vomiting, lethargy, increased thirst, kidney failure. Onset 12 to 36 hours. The home response: emergency vet visit. Treatment is prolonged and expensive.
Bromethalin rodenticides. Cause cerebral edema and severe neurological signs. Symptoms: ataxia, tremors, seizures, hyperthermia, coma. Onset 1 to 7 days. There is no antidote. The home response: emergency vet visit, although the prognosis is poor once symptoms develop.
Zinc phosphide rodenticides. Cause phosphine gas release in the stomach. Symptoms: vomiting (sometimes with blood), respiratory distress, collapse, death. The home response: do not approach the mouth (the gas is toxic to humans too). Get the animal to the vet.
The four mistakes
Mistake 1: Waiting to see if the pet seems fine. Many toxins have delayed onset. The pet seems fine at 4 pm. By 10 pm, the pet is seizing. By morning, the pet is dead. The home response is "call the vet immediately," not "wait and see." The vet will often induce vomiting or use activated charcoal to decontaminate within the first 2 to 4 hours, which is far more effective than treating the symptoms after they develop.
Mistake 2: Inducing vomiting without veterinary advice. The internet is full of "give your dog hydrogen peroxide to make him vomit" advice. This is sometimes correct, sometimes catastrophic. Do not induce vomiting for caustic substances (the material will burn the esophagus again on the way up). Do not induce vomiting for hydrocarbons (the fumes will be inhaled into the lungs). Do not induce vomiting for pets that are already showing neurological signs (the aspiration risk is high). The default is to call the vet and follow the vet's instructions.
Mistake 3: Assuming the dose was too small to matter. Toxic doses are not always intuitive. A single grape can cause kidney failure in some dogs. A single raisin can be fatal in cats. A single acetaminophen tablet can kill a cat. The dose threshold is not always clear, and breed and individual sensitivity vary. The safe assumption is: any potentially toxic exposure warrants at least a phone call to the vet.
Mistake 4: Failing to bring the packaging. The vet needs to know what was eaten, in what quantity, and how long ago. The packaging, the wrapper, the plant label, the bottle — any of these can tell the vet the active ingredient and the dose. The owner who arrives at the clinic without the packaging has lost critical information. Take five seconds to grab the wrapper, the plant tag, or the bottle on the way out the door.
The household checklist
A quick household safety review:
- All foods stored in closed cabinets or high shelves, never on counters
- All medications in closed cabinets, never in weekly pill organisers left on counters
- Xylitol-containing products (gum, candy, peanut butter, baked goods) identified and stored away
- All cleaning products in closed cabinets
- Antifreeze stored in sealed containers, spills cleaned up immediately
- All lilies removed from the home if there is a cat
- All rodenticides placed in areas inaccessible to pets
- Essential oil diffusers used in well-ventilated areas, with pets able to leave the room
- Sago palms and other toxic plants removed from the home and yard
This is not a complete list. It is a starting point. The more you know about the specific products in your home, the better you can protect your pet.
Closing the loop
The vast majority of pet toxicities are preventable. The owner who keeps toxic foods in closed cabinets, who stores medications safely, who identifies and removes toxic plants, who uses pet-safe cleaning products, and who knows the local emergency vet number, will rarely need this article. The owner who leaves a chocolate bar on the coffee table, who keeps a bottle of ibuprofen in an open purse, who plants lilies in the garden with a cat in the house, will eventually need all of it. The toxin is the same in both cases. The difference is preparation.
