Are Matches toxic to dogs?

Match heads contain potassium chlorate, an oxidizing agent. A few heads irritate the gastrointestinal tract; a large number can damage red blood cells (methemoglobinemia and hemolysis) and the kidneys.

None of the sources we checked gives a treatment plan written for matches, so the vet treats the chlorate and the signs. For fireworks, which can also contain chlorates, an ASPCA toxicologist describes this approach. If the pet has no signs and ate them less than 1 hour earlier, the vet may make it vomit. Mineral oil may stop chlorate from being absorbed and speed its way through the gut, though it is given with care: oil breathed into the lungs can inflame them. Activated charcoal isn't recommended, because it doesn't bind chlorates. Care can include a drip (IV fluids), oxygen for a pet with blue gums, a blood count, and liver and kidney tests at the start and again at 24, 48 and 72 hours. If chlorate damages the blood, the vet can give methylene blue (or N-acetylcysteine if it isn't available), sometimes with vitamin C, to help turn methemoglobin back into hemoglobin, and blood transfusions for anemia. The Merck Veterinary Manual, writing about chlorate weed killers in livestock, explains why methylene blue has to be repeated: chlorate isn't used up as it damages hemoglobin, so it keeps doing so for as long as it stays in the body. Merck adds that IV saline can speed its removal.

None of the sources we checked gives recovery rates or case numbers for dogs that ate matches. The outlook depends on how much your dog ate: Pet Poison Helpline says a few match heads cause stomach and gut irritation, while a large number can damage the kidneys and red blood cells. The ASPCA says the chlorates in certain matches could lead to kidney disease in severe cases, and warns that red blood cell damage from chlorates in fireworks can quickly become life-threatening. Poisonings can be harder to treat once signs appear, according to the ASPCA, so call early.

• Match heads. Pet Poison Helpline says match heads contain potassium chlorate, a chemical that makes the match burn quickly. Depending on the type, match tips can also contain potassium dichromate, sulfur and phosphorus sesquisulfide, according to the US Poison Control center. The Animal Poisons Helpline in Australia says the red material on match heads generally contains small quantities of chlorate salts.
• Two kinds of matches. Strike-anywhere matches carry all their reactive chemicals on the tip and light on any hard, rough surface, such as brick. Safety matches light only on the striker strip of their box or matchbook, which holds the phosphorus chemical. Matches usually come in books of 20 cardboard matches or in boxes of wooden ones. The veterinary sources we checked don't compare the risk of the two kinds for pets.
• The sticks. Wooden matchsticks can block the stomach or gut of very small dogs and cats, according to Pet Poison Helpline, and the Animal Poisons Helpline adds that sharp wood splinters could injure a pet on the way down.
• Around fires and celebrations. The Animal Poisons Helpline gets calls about dogs eating matches and firelighters in cold weather, when households light fires. The ASPCA lists matches, along with lighter fluid, among its Fourth of July hazards for pets.

• Keep matches, and lighter fluid, out of your pets' reach.
• Store matches and firelighters where pets can't get at them, especially in cold weather, when the Animal Poisons Helpline gets calls about dogs eating both.
• Pick up any dropped matches and matchsticks. Wooden sticks can block the gut of very small dogs and cats.
• Keep fireworks and sparklers out of reach too, and pick up their remains before letting pets out. Some fireworks contain chlorates as well.