Household Products Toxic to Pets: What to Keep Away from Dogs and Cats
The family home contains a surprising number of substances that can seriously harm or kill dogs and cats. Unlike food hazards, many of these products are not something pets would ordinarily eat, but accidental exposure through ingestion, skin contact, inhalation, or grooming is more common than owners expect. This guide covers the most dangerous household product hazards for pets, with particular attention to the risks that are most frequently overlooked.
Critical Warnings: These Can Kill
Permethrin — Fatal to Cats from Dog Flea Treatments
Permethrin is a synthetic pyrethroid insecticide widely used in spot-on flea treatments for dogs. Products including Advantix and many generic permethrin spot-ons are highly effective for dogs but are extremely toxic to cats. Cats lack the liver enzyme required to metabolise permethrin, and exposure — even indirect exposure — can be fatal.
The risk to cats is not limited to direct application of a dog product to the cat. A cat that grooms or rubs against a dog that has recently been treated with a permethrin spot-on can absorb a dangerous dose through that contact alone. The product must be fully dry before a treated dog and cat are in the same space, and ideally the two animals should be kept separated for 24 hours after application.
Signs of permethrin toxicity in cats appear rapidly and include intense muscle tremors and twitching (particularly visible in the facial muscles and ears), hypersalivation, incoordination, dilated pupils, hyperthermia, and seizures. This is a life-threatening emergency. If you suspect your cat has been exposed to permethrin, wash the product off immediately using washing-up liquid and warm water, then take your cat to an emergency vet without delay. Do not wait to see whether symptoms develop.
Always check the active ingredients of any flea or tick treatment before use, and never apply a product labelled for dogs to a cat. When in doubt, ask your vet to recommend a cat-appropriate product.
Antifreeze (Ethylene Glycol)
Antifreeze is one of the most dangerous household products for both dogs and cats, and it is responsible for a significant number of pet deaths every year. Ethylene glycol, the active ingredient in most antifreeze products, has a sweet taste that is attractive to animals, which means pets may actively seek it out if it has dripped onto a garage floor or driveway.
The lethal dose is very small — particularly for cats. As little as 1.5 millilitres per kilogram of body weight can be fatal in cats; dogs require a higher dose but are still at serious risk. Ethylene glycol is metabolised in the liver into compounds that cause catastrophic kidney failure.
The clinical course of antifreeze poisoning is deceptive and accounts for many delayed presentations. Within 30 minutes to eight hours of ingestion, a pet may appear drunk — uncoordinated, lethargic, and vomiting. These initial signs often resolve, giving the false impression that the animal has recovered. In reality, the metabolic damage is progressing. Within 24 to 72 hours, acute kidney failure develops, and at that point survival is much less likely.
If you have any reason to believe your pet has been exposed to antifreeze, contact your vet immediately, even if the animal appears fine. Time is critical: an antidote exists (ethanol or fomepizole), but it must be administered within a few hours of ingestion to be effective. Keep antifreeze in sealed containers, clean up any spills immediately, and consider switching to a propylene glycol-based antifreeze, which is considerably less toxic.
Rodenticides (Rat and Mouse Poison)
Rodent poisons are commonly placed in homes and gardens, often in locations that pets can access. The most widely used rodenticides in the UK are anticoagulants — compounds that prevent blood from clotting, leading to internal haemorrhage. Second-generation anticoagulants such as brodifacoum, bromadiolone, and difenacoum are particularly potent and persistent.
A critical but often overlooked risk is relay toxicity: a cat or dog can be poisoned not by eating the rodenticide directly, but by eating a rodent that has itself consumed poison. This is a real and well-documented cause of pet poisoning.
Because anticoagulant rodenticides work slowly, symptoms typically do not appear for three to five days after ingestion, by which time severe internal bleeding has already begun. Signs include unexplained lethargy, pale gums, difficulty breathing, swollen abdomen, blood in urine or faeces, and nosebleeds. An antidote exists — Vitamin K1 — but it must be administered and continued under veterinary supervision, typically for four to six weeks depending on the compound involved.
If you suspect your pet has eaten rodenticide or a poisoned rodent, do not wait for symptoms. Seek veterinary treatment immediately and tell the vet which product was used if you know it.
Human Medications
Human medications are among the most common causes of pet poisoning calls to animal poison helplines. Several are critically dangerous.
Paracetamol (acetaminophen) is fatal to cats even in single tablet doses. Cats are unable to safely metabolise paracetamol through glucuronidation, and the compound accumulates to toxic levels very rapidly, causing liver failure and damage to red blood cells (methaemoglobinaemia). Dogs are also susceptible to paracetamol toxicity, though they require a larger dose. Never give paracetamol to a cat under any circumstances, and consult your vet before giving any pain relief to a dog.
Ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs) designed for human use cause severe gastrointestinal ulceration and acute kidney failure in both dogs and cats. Even a single tablet can cause serious harm in small animals. Never give human NSAIDs to pets without explicit veterinary instruction.
Antidepressants, including SSRIs such as fluoxetine and sertraline, and opioid pain medications such as tramadol, are also seriously toxic to pets and can cause seizures, cardiovascular effects, and respiratory depression. Store all medications in sealed containers in secured cupboards inaccessible to pets.
Serious Hazards Requiring Veterinary Attention
Essential Oils
Essential oils have become increasingly popular in home diffusers and cleaning products, but many are toxic to pets — and cats are particularly vulnerable. Tea tree oil (melaleuca), eucalyptus, peppermint, clove, and cinnamon essential oils are among the most dangerous. Cats lack the liver enzymes needed to detoxify phenolic compounds found in many essential oils, making them far more susceptible to toxicity than dogs or humans.
Exposure can occur through direct skin contact, ingestion through grooming, or inhalation from diffusers. Ultrasonic diffusers that disperse oil particles into the air can cause respiratory irritation and systemic toxicity in cats over time, even when the oils are not applied directly. Avoid using essential oil diffusers in rooms where cats spend time, never apply essential oils directly to any pet, and keep oil products in sealed containers. Dogs are also sensitive to some essential oils, particularly tea tree oil.
Cleaning Products
Many household cleaning products pose a risk to pets that walk across treated surfaces and then groom their paws, or that come into direct contact with chemicals. Bleach and ammonia-based products cause chemical burns to the mouth, oesophagus, and stomach if ingested. Phenol-based disinfectants — including the original formulation of Dettol — are particularly toxic to cats, whose livers cannot metabolise phenols. Oven cleaners and toilet bowl cleaners are highly caustic and can cause severe burns.
Always allow surfaces to dry completely before allowing pets back into a room. Store all cleaning products in secured cupboards, rinse surfaces after cleaning if pets will walk on them, and consider switching to pet-safe cleaning products where possible.
Zinc Toxicity from Batteries and Coins
Batteries, particularly button batteries, and coins minted since 1992 in the UK (which contain zinc) can cause haemolytic anaemia if swallowed. Zinc is absorbed from the digestive tract and destroys red blood cells. Signs include lethargy, pale gums, vomiting, and jaundice. Battery ingestion also carries the risk of chemical burns from battery acid. Any ingestion of a battery or coin should be treated as an emergency requiring x-ray and likely surgical retrieval.
Paints and Solvents
White spirit, turpentine, and similar paint thinners are irritant to the skin, gastrointestinal tract, and respiratory system. Pets that walk through spilled solvents or freshly painted surfaces and then groom themselves may ingest significant quantities. Signs include vomiting, drooling, coughing, and in severe cases, respiratory distress or neurological signs. Ventilate rooms during and after painting and keep pets out until surfaces are fully dry and fumes have cleared.
What to Do in a Household Product Emergency
- Identify the product involved and read the label for the active ingredients.
- Note the time of exposure and the estimated amount your pet may have contacted or ingested.
- Call your vet or an emergency animal hospital immediately. In the UK, the Animal Poison Line can be reached on 01202 509000 (a fee applies).
- For skin or coat contamination (such as permethrin or solvent), wash the substance off with washing-up liquid and water before travelling to the vet, unless you are instructed otherwise.
- Do not induce vomiting unless specifically instructed by a veterinary professional. Caustic products such as oven cleaner or bleach can cause additional damage to the oesophagus if vomited.
- Bring the product packaging to the vet if possible — the full ingredient list helps determine the correct treatment.
Many of these emergencies are entirely preventable. Store hazardous chemicals, medications, and pest control products in secured cupboards beyond the reach of pets. Regularly audit your garage, utility room, and garden shed for products that could harm animals. Use pet-appropriate alternatives wherever possible, and always read product labels for warnings before introducing anything new into your home.