Watergum’s humane euthanasia policy for cane toads

Here at Watergum, we only believe in the humane and ethical treatment of animals, even if they are an invasive species. Cane toads deserve to be treated kindly and humanely, after all it is not their fault they are on the wrong continent, they were put here by US!

When euthanising cane toads at all life stages, Watergum recommends and encourages everyone to use the most humane way currently recognised which is available to the general public – the cooling and freezing method.

The cooling and freezing method involves refrigerating toads for up to 24 hours before transferring them to the freezer.

Why does Watergum recommend the cooling and freezing method?

The research to support the declaration of this method being humane is available here and was conducted in 2015. This research monitored body temperatures and the brain activity of cane toads throughout cooling and freezing which shows that they slip into a coma-like state (called torpor) during the cooling period which inhibits brain activity and prevents their brain from recognising the pain experienced from ice crystals forming in their veins which occurs during freezing. This confirms that cooling and then freezing is a humane method of euthanasia.

Controversially, many organisations follow these research guidelines which are out of date. In this document, the most recent research cited for the cooling and freezing method was conducted in 1999 and it was deemed inconclusive (and therefore not recommended) due to the inability to understand the effects of cooling and whether or not they were inhumane. Instead, this paper recommends chemical treatment (despite it being deemed inhumane), decapitation and CO2 exposure. The following points iterate why these methods are unsuitable for use by the general public and for Watergum’s Cane Toad Challenge program.

Chemical Treatment

  • It is inhumane,

In the UOW trials, after being sprayed according to the manufacturers instructions, toads exhibited a range of behaviours consistent with distress. These included limbflicking, urination and blepharospasm and avoidance of the spray which included crawling and hopping movements and attempted burrowing in the corner of the container. After a few minutes some toads developed ataxia, and most stopped moving and lay with their chins down until death. The ventral skin also turned red and the average time to death was 19 minutes (range from 5 to 36 minutes).’


  • Method makes toads unsuitable for lure production. Toads killed with chemicals can not be used for lure production as we can not add chemicals to the waterway

Stunning and Decapitation

  • Large margin for error and improper execution leading to inhuman torture of toads and possible injury of general public.
  • Unsuitable for under 18s which rules out a significant section of target audience of the program. Toad busting success requires high numbers of engaged persons, including family groups and also relies on appropriate education for children to teach them the importance of protecting native species and the threats presented by highly invasive species.
  • Watergum can not and will not engage children or adults in violent and unethical practises.
  • Method leaves toad toxin in the environment. Bashing and decapitating toads can rupture the parotoid glands resulting in the toxin being splattered into the environment where it still presents a danger to pets and wildlife. If a dog comes along and licks toxin from the floor its life will be in danger.
  • Method makes toads unsuitable for lure production. The method can rupture and destroy the parotoid gland which is the part we use to make tadpole lures.

Carbon Dioxide for 4+ hours

  • Not suitable for the general public. While more humane than most methods, this method is not practical or safe for use by the general public.

In conclusion..

We recommend the cooling and freezing method for euthanasia of cane toads of all life stages as it is the most humane method that is available to the general public.

We would hope that our members strive to be humane an ethical in their treatment of all living things.