Poisoning is a common reason for emergency visits to the vet. Often, a dog or cat is poisoned by eating something that is harmless to us but toxic to them, such as chocolate, xylitol or grapes — or by getting into human medicines. How ill the animal becomes depends on the substance, the amount swallowed and the animal’s size. A suspected poisoning is always worth an immediate call to your vet, even if your pet still seems perfectly well. For many poisons, treatment works best — or only works — before any signs appear.
Dangerous foods
The substances that most often cause trouble are chocolate, xylitol, grapes and raisins, and onion and garlic. Chocolate and cocoa contain theobromine — the darker the chocolate, the more dangerous it is. Xylitol is a sweetener found in chewing gum, pastilles, sweets, some baked goods and toothpaste. In dogs it causes a sudden drop in blood sugar and, at larger doses, liver damage. Grapes and raisins can cause kidney failure in dogs, and there is no known safe amount. Onion and garlic in any form — raw, cooked or powdered — damage the red blood cells, and cats are even more sensitive to them than dogs.
Rat poisons, medicines and other dangers
Rat and mouse poisons work in different ways. Anticoagulant baits, still sold to consumers in Finland in ready-filled bait boxes for indoor use, cause internal bleeding. Alpha-chloralose has poisoned many cats in Finland, often through eating poisoned mice. It causes unsteadiness, oversensitivity to touch, twitching, seizures and a dangerous drop in body temperature. Its sale to consumers ended in August 2023, but pest-control professionals may still use it and old stock may remain in homes, so outdoor cats can still be exposed. Antifreeze (ethylene glycol, found in engine coolant) tastes sweet. As little as a teaspoonful of undiluted antifreeze can kill an average-sized cat, and dogs are at risk too. Human painkillers are another common culprit: ibuprofen can cause stomach ulcers and kidney damage, and even part of a single paracetamol tablet can kill a cat. Permethrin, found in some dog flea and tick spot-ons and in some scabies creams for people, is highly toxic to cats. Never use a dog product on a cat. A cat can be poisoned just by close contact with a freshly treated dog, or by licking the skin, towels or bedding of a person using the cream. Lilies, including day lilies, are especially dangerous to cats: pollen groomed off the fur, a nibble of leaf or even the vase water can cause fatal kidney failure. In summer, blue-green algae blooms in lakes and the sea can poison dogs that swim in or drink the water. Signs can start within minutes, though some appear only hours later.
Symptoms
The signs vary from one poison to the next. The most common are vomiting, diarrhoea, drooling, tummy pain, loss of appetite and lethargy. Neurological signs may include twitching, tremors, seizures, loss of balance, restlessness or collapse. In severe cases you may see rapid breathing, a racing heart, pale, yellowish or brownish gums, blood in the vomit or stools, an abnormally low or high body temperature, or loss of consciousness. Not every poison shows itself straight away. Bleeding from anticoagulant rodenticides usually starts three to seven days later, anaemia from onion or garlic appears after a few days, and kidney damage from lilies or grapes within one to three days. Antifreeze can first cause a drunken, unsteady state within hours; your pet may then seem to improve before serious kidney damage sets in. That is exactly why you should act at once on any suspicion, rather than wait for symptoms.
First aid
Ring your vet straight away and tell them what your pet has swallowed, how much, when, and roughly what your pet weighs. Bring the packaging, or a photo of it, to the clinic. Do not try to make your pet sick yourself. Salt can cause dangerous salt poisoning, and hydrogen peroxide can injure the stomach lining and is particularly dangerous for cats. Vomiting is also harmful after corrosive or oily products, or if your pet is drowsy or fitting. Do not give milk or oil either: they neutralise nothing and can make matters worse. If there is poison on the skin or coat — or after a swim in water with an algae bloom — wear gloves and rinse the skin and coat with plenty of clean, lukewarm tap water (add a little mild washing-up liquid for oily products). Dry your pet well and stop it licking the area. Do not bathe a pet that is twitching or fitting. Keep your pet calm and quiet on the journey in. Wrap a cat that feels cold in a blanket, keep a twitching or oversensitive pet somewhere quiet and dim, and keep your hands away from the mouth of a pet that is fitting. Only your vet can judge whether making your pet sick is still worthwhile. It usually helps only within the first hour or two after swallowing, although for some poisons the window is longer. Please note that the Poison Information Centre (Myrkytystietokeskus) does not advise pet owners on animal poisonings. For your pet, always call a vet.
Veterinary treatment
Treatment depends on the poison and how long ago it was swallowed. Early on, your vet may bring on controlled vomiting with medicine and give activated charcoal, which binds some poisons in the gut. Supportive care includes intravenous fluids, anti-sickness and anti-seizure medication, temperature control and close monitoring of vital signs. A few poisons have a specific antidote. For anticoagulant rodenticides it is vitamin K1, usually given for four weeks or more until a blood clotting test is normal. For antifreeze it is fomepizole or ethanol, which only work if started within hours of swallowing — in cats ideally within three hours — before the kidneys are damaged. Many poisons, including alpha-chloralose, permethrin, lilies and blue-green algae, have no antidote, which is why early treatment matters so much. Severe cases need admission to hospital, with blood tests to keep an eye on kidney and liver function and blood clotting. The sooner treatment starts, the better the outlook.
Prevention
Keep medicines, sweets, xylitol products, cleaning agents and antifreeze well out of your pet’s reach. Never give human food or medicine without checking with your vet first, and never use a dog’s flea treatment on a cat. Keep cats apart from a dog for at least three days after it has been treated with a permethrin product. Keep cats away from anyone using a permethrin scabies cream, and from that person’s towels and bedding. Keep your dog on the lead anywhere rodenticide or rubbish might be lying about, and avoid poison baits where your own or your neighbours’ cats roam. Do not keep lilies in a home with a cat, and check whether your houseplants are toxic. In summer, keep your dog out of water with a visible algae bloom. Save Saari Animal Clinic’s number, (06) 321 7300, and the regional out-of-hours emergency number, 0600 399 299, in your phone now, so that help is close at hand should the worst happen.
Sources
- Merck Veterinary Manual: Chocolate Toxicosis in Animals. merckvetmanual.com
- Merck Veterinary Manual: Xylitol Toxicosis in Dogs. merckvetmanual.com
- Merck Veterinary Manual: Garlic and Onion (Allium spp) Toxicosis in Animals. merckvetmanual.com
- MSD Veterinary Manual: Grape, Raisin, and Tamarind Toxicosis in Dogs. msdvetmanual.com
- Merck Veterinary Manual: Ethylene Glycol Toxicosis in Animals. merckvetmanual.com
- Connally H.E. ym. (2010): Safety and efficacy of high-dose fomepizole compared with ethanol as therapy for ethylene glycol intoxication in cats. Journal of Veterinary Emergency and Critical Care 20(2):191–206. pubmed.ncbi.nlm.nih.gov
- Merck Veterinary Manual: Anticoagulant Rodenticide Poisoning in Animals. merckvetmanual.com
- Merck Veterinary Manual: Toxicities from Over-the-Counter Drugs. merckvetmanual.com
- Merck Veterinary Manual: Houseplants and Ornamentals Toxic to Animals. merckvetmanual.com
- Merck Veterinary Manual: Algal Poisoning of Animals. merckvetmanual.com
- ASPCA Animal Poison Control Center: People Foods to Avoid Feeding Your Pets. aspca.org
- ASPCA: Is It Ever Safe to Induce Vomiting? aspca.org
- Pet Poison Helpline: Five Pet Poisoning First Aid Misconceptions. petpoisonhelpline.com
- International Cat Care: Lily poisoning in cats. icatcare.org
- International Cat Care: Paracetamol poisoning in cats. icatcare.org
- International Cat Care: Permethrin poisoning. icatcare.org
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