Five Common Weeds Poisonous To Horses In Australia


It’s important to watch out for weeds that are poisonous or deadly to horses in Australia, but it’s also good to know how to prevent them, here we discuss five common weeds that are poisonous to horses in Australia, and how Bioweed can help maintain a safe paddock for your equine.

More often than not, horses are quite selective with what they choose to consume. Most generally won’t eat weeds unless there is nothing else to devour, making it easier for you to keep an eye on what kind of plants call your pastures home.

While they may affect the equine realm differently and on a case by case scenario, the most common weeds that are poisonous to horses in Australia include:

  • Grey Swainsona – In favourable conditions, this plant can grow as tall as 60cm. Common in Western Australia, South Australia, Queensland and the Northern Territory, this plant flowers between May and December and is considered to be highly toxic to horses and other livestock.
  • Hemlock – This plant is rarely grazed by horses and livestock, but poisoning can occur via chaff and hay distribution. Declared a noxious weed in Victoria, New South Wales and Western Australia, signs of piperidine alkaloid poisoning associated with hemlock consumption can include dilated pupils, muscle weakening, and respiratory failure in severe cases.
  • Paterson’s Curse – Also dubbed “Salvation Jane” or “Riverina Bluebell”, this highly toxic weed is native to the Mediterranean region but can be found in all Australian states. Upon consumption, the poisoning can be acute or progressive, with horses usually presenting wildly different behaviours than usual ultimating in organ shutdown (particularly liver) until death.
  • Fireweed – Common in pastures along Australia’s East Coast, fireweed is capable of rapidly taking over paddocks through the small daisy like yellow flowers – each plant is able to produce up to 30,000 seeds a season. Symptoms to watch out for include aimless wandering or uncoordination, and poisoning can result in brain damage and liver failure.
  • Nightshade – With over one hundred different varieties present across all states of Australia, and is actually closely related to the tomato plant. Shrubs may produce flowers and/or berries, with all sections of the plant presenting varying toxicity levels to horses. Depending on the amount consumed and condition of the horse, nightshade can induce colic, diarrhoea, paralysis and intestinal stasis if left untreated.

These are just a handful of weeds in Australia that are considered toxic to horses and other grazing animals. For a comprehensive guide, please refer to the “Plants Poisonous To Horses” Field Guide produced by the Australian Government.

How To Prevent Weeds That Are Poisonous To Horses

When it comes to getting on top of weed issues in your paddock or pasture, prevention is often the key. When left unchecked, an infestation of weeds toxic to your animals can be difficult to get under control – so it’s important to stay one step ahead.

Backed with over twenty years of research and development, if you’re looking for a commercial pesticide-free weed killer for your animals then Bioweed may be the solution. Both fast-acting, economical and glyphosate-free, it’s a safer alternative for both you and your horses when it comes to addressing weed issues.

Our very own horse enthusiast Logan Brown actively uses Bioweed on her property and loves the convenience of not having to move her livestock or keep an eye on her dogs when spraying.

“My advice for using Bioweed would be to ensure that if you’re controlling taller broadleaf weeds, try and slash them before applying the Bioweed. It will make sure you get full coverage of the plant and ensure you get the best results quickly and economically.”

Want to know more about eliminating your weeds – pesticide free? Check out other tips and tricks in our online Advice forum, or contact us for any further queries.