With the cooler weather well upon us, the Animal Poisons Helpline has noted a significant increase in calls regarding dogs ingesting single use hand warmers. Single use hand warmers typically contain iron powder and smaller quantities of salt, water, an absorbent material (e.g. vermiculite) and activated carbon. When the pouch is removed from its outer packaging, oxygen diffuses across the pouch’s permeable outer layer reacting with the iron powder to produce heat.

From a poisoning perspective the main constituent of concern in these warmers is iron. The risk of iron poisoning is dependent on the amount ingested, the weight of the animal and if the warmer has already been used or not. Poisoning can result in anything from minor gastrointestinal upset to severe gastroenteritis (with blood in the vomit and/or stool), low blood pressure and liver failure. Ingestion may also carry a risk of a gastrointestinal blockage if the hand warmer packet is swallowed in its entirety.

If you have any single use heat packs in your house, please ensure that they are kept well out of reach of your pets and ensure any used packs are disposed of appropriately. The Animal Poisons Helpline provides free advice to pet owners in Australia and New Zealand and can be reached on☎️ 1300 869 738 (AU) ,0800 869 738 (NZ), 3106 4216 (SG), (917) 722-5958 (US) or +1917-722-5958 (CA) . If you are a member of a veterinary team in Australia or New Zealand, you can join the Animal Poisons Centre For Vets Facebook group which is regularly updated with toxicology tidbits and poisoning trends. We thank the Western Australian Department of Primary Industries and Regional Development for supporting this post.