Household Items That Are Toxic to Pets

Your home is full of products that are perfectly safe for you but potentially deadly for your pet. As pharmacists, we handle many of these substances every day — pain relievers, supplements, cleaning products — and we know exactly how dangerous they can be when a curious dog or cat gets into them.

Here's what every pet owner in Ottawa should know about the most common household toxins, organized by where you're most likely to find them.

In the Medicine Cabinet

This is the most dangerous room in the house for pets. Many human medications are highly toxic to dogs and cats, even in small amounts.

Acetaminophen (Tylenol®): A single regular-strength tablet can be fatal to a cat. Acetaminophen destroys cats' red blood cells and causes liver failure. Dogs are somewhat more tolerant, but doses above 100 mg/kg are still toxic. Never give your pet any human pain reliever.

Ibuprofen (Advil®, Motrin®): Even one tablet can cause stomach ulcers and kidney failure in dogs and cats. Cats are especially sensitive — as little as 50 mg can be dangerous.

Naproxen (Aleve®): Extremely toxic to dogs. A single 220 mg tablet can cause serious GI ulceration in a medium-sized dog. The long half-life means the drug stays in your pet's system for an extended period.

5-Fluorouracil (5-FU) cream: This prescription skin cancer cream (Efudex®) is one of the most dangerous topical medications for dogs. Even a small exposure — licking the tube or the treated skin — can be rapidly fatal. Store securely and prevent any contact with pets.

Vitamin D supplements and calcipotriene cream: Vitamin D toxicity causes dangerously elevated calcium levels, leading to kidney failure. Both oral vitamin D supplements and topical psoriasis creams containing calcipotriene (Dovonex®) are significant risks.

Iron supplements: Prenatal vitamins and iron tablets can cause severe GI damage and liver failure in pets. Even the sugar-coated tablets that dogs find palatable can be extremely dangerous.

Pseudoephedrine and phenylephrine: Decongestants found in many cold and allergy medications. These stimulants can cause dangerous heart rate elevations, tremors, and seizures in pets.

In the Kitchen

Chocolate: The darker the chocolate, the more dangerous it is. Chocolate contains theobromine and caffeine, which dogs metabolize much more slowly than humans. Baking chocolate is the most toxic — as little as 1 ounce per pound of body weight can be lethal. Dogs that eat more than 20 mg/kg of methylxanthines may show GI signs; more than 40-60 mg/kg can cause heart problems and seizures. Keep baking chocolate especially well secured.

Xylitol: This sugar substitute is found in sugar-free gum, some peanut butters, baked goods, chewable vitamins, and even some medications including gabapentin oral liquid. In dogs, xylitol causes a rapid, dangerous drop in blood sugar and can lead to liver failure. As little as 0.1 g/kg can be harmful. Always check labels.

Grapes, raisins, and currants: These fruits are toxic to dogs. They contain tartaric acid, which can cause acute kidney injury. Even small amounts are concerning, and there's no established safe dose.

Onions, garlic, leeks, and chives: All allium-family plants can damage red blood cells in dogs and cats, leading to anemia. The effects may not appear for several days after ingestion.

Bread dough: Raw yeast dough continues to rise in your pet's stomach, producing gas (risking bloat and torsion) and alcohol (risking ethanol toxicosis).

In the Garage and Under the Sink

Ethylene glycol (antifreeze): One of the most dangerous household toxins. It tastes sweet, attracting pets. The lethal dose is just 1.5 mL/kg in cats and 4.2-6.6 mL/kg in dogs. Toxicity progresses through stages from neurological signs to kidney failure. If you suspect ingestion, this is a true emergency — treatment must begin within hours. Look for "pet-safe" antifreeze containing propylene glycol instead.

Rodenticides (rat poison): Anticoagulant rodenticides (brodifacoum, bromadiolone) prevent blood clotting. Signs may not appear for 3 to 5 days. Vitamin K1 is the antidote, and treatment may be needed for weeks. Bromethalin-based rodenticides cause brain swelling and have no antidote.

Metaldehyde (slug and snail bait): Causes rapid-onset seizures, tremors, and hyperthermia. Can be fatal within hours.

Around the House

Lily plants: Extremely dangerous for cats. Easter lilies, stargazer lilies, and tiger lilies can cause kidney failure even from small exposures to leaves, petals, pollen, or vase water. If you have cats, do not bring lilies into your home.

Permethrin: Found in many flea and tick products labeled for dogs. Permethrin is highly toxic to cats and can cause fatal seizures. Never apply a dog flea product to a cat, and be cautious if your cat grooms or sleeps near a recently treated dog.

Lithium batteries: If swallowed, the electric current can cause severe chemical burns to the esophagus and stomach in as little as 15 minutes. Seek emergency care immediately.

Essential oils: Many essential oils are toxic to cats, including tea tree, peppermint, citrus, and eucalyptus oils. Cats lack certain liver enzymes needed to metabolize these compounds. Even diffusing essential oils can be problematic for cats in enclosed spaces.

Cannabis edibles: With legalization in Canada, THC edibles are an increasingly common toxicity in pets. Dogs are especially sensitive and can develop severe neurological symptoms including loss of coordination, urinary incontinence, and in severe cases, coma.

What to Do in an Emergency

If you suspect your pet has ingested something toxic:

1. Don't panic, but act quickly. Time matters with most toxicities.
2. Do NOT induce vomiting unless specifically instructed to by a veterinarian or poison control. Some substances cause more damage coming back up.
3. Bring the product packaging with you to the vet or have it ready when you call. The exact ingredient list and concentration help determine treatment.
4. Call your veterinarian or an emergency animal hospital immediately.
5. Contact a poison control hotline:

• ASPCA Animal Poison Control: 1-888-426-4435 (consultation fee applies)
• Pet Poison Helpline: 1-855-764-7661 (consultation fee applies)