The Animal Poisons Helpline is occasionally contacted about companion animals that have been exposed to pre-emergent herbicides. Whilst there are several pre-emergents available in Australia and New Zealand, calls regarding oxadiazon and prodiamine are the most common. Pre-emergent herbicides are growing in popularity as they are an effective preventative approach to weed control in turf. They work by inhibiting germination of the weed at the shooting or sprouting stage in the top layer of the soil.

Small ingestions of these products may result in gastrointestinal signs such as vomiting, diarrhoea and inappetence. Large ingestions, such as what may occur when an animal has direct access to product packaging, may result in more severe signs. Whilst serious effects are unlikely from small ingestions of these products, we recommend that the following safety measures are observed when using these products:

✅ Keep pets away from treated areas during application and until the area is thoroughly dried. The time taken for the area to dry will vary depending on local weather conditions and the product formulation.

✅ If you are using a concentrate that requires dilution before spraying, always follow the instructions in terms of appropriate dilution and keep your pet away whilst measuring and mixing.

✅ Ensure all herbicides are stored safely, well out of reach of companion animals. Be aware that cats can jump onto high surfaces and knock products over. They may walk through spilt puddles and then groom chemicals off their paws or coat.

The Animal Poisons Helpline provides free advice to pet owners in Australia 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, New Zealand or Singapore, you can join the Animal Poisons Centre For Vets Facebook group which is regularly updated with toxicology tidbits and poisoning trends.