Careful product selection can not only optimise the success of your rodent control program but help to minimise the unintentional poisoning of non-target species.

Rats and mice can cause significant financial losses by damaging crops, stored grain, fodder and farm infrastructure.

They can also transmit a range of zoonotic diseases, such as Salmonella and Leptospirosis, to livestock and humans. 

While a plethora of effective rodenticide products are available, Elanco brand manager, Kim Krilich, says it’s important to check what’s inside the pack.

“Rodenticides are formulated in different ways, and this influences how they should be used,” she says.

“Second-generation anti-coagulant rodenticides have long half-lives and pose a particular threat to a range of non-target species that feed on poisoned carcases.

“These highly potent poisons are slower to break down than first generation anti-coagulant rodenticides and therefore remain at lethal concentrations inside the bodies of poisoned rats and mice longer, placing anything that eats those carcases at risk.

“This can include natural predators, such as owls, eagles and snakes, as well as pets and working dogs.”

A recent study by researchers from several Australian universities and government departments highlighted the extent of secondary poisoning caused by second-generation rodenticides.

This study detected residues of anti-coagulant rodenticides in five key native marsupial carnivores in Australia, namely Tasmanian Devils, Chuditch, and the Northern, Eastern and Spotted-tailed Quoll._¹

“Alarmingly, 26 of the 52 animals tested positive for anti-coagulant rodenticides and of these, 11 tested positive for more than two active ingredients and two tested positive for three,” Kim says.

“About a fifth of these animals were diagnosed as being likely to die from poisoning or related illnesses.

“All five of these species are already threatened, meaning their populations are a fraction of what they used to be.

“Even small changes to populations can trigger more rapid decline.”

Four other threatened species – the Tasmanian Wedge-tailed Eagle, Tasmanian Masked Owl, Powerful Owl and Carnaby’s Black Cockatoo – have previously been found to be exposed to these rodenticides.

This study illustrates the extent of rodenticide residues in non-target species and reiterates the need for careful consideration and use of rodenticides to mitigate these impacts.

The Australian Pesticides and Veterinary Medicine Authority (APVMA) is currently reviewing the use of second-generation rodenticides, including brodifacoum, bromadiolone, difethialone, difenacoum and flocoumafen.

Some countries have banned the use of second-generation rodenticides, while their use in Europe and North America is now restricted to licensed pest controllers.

Kim says it is widely accepted that first-generation rodenticides, such as coumatetralyl, pose a very low risk of secondary poisoning to non-target species.

Coumatetralyl is the active ingredient found in the Racumin rodenticide range from Elanco.

“Coumatetralyl is a multi-dose anti-coagulant, which means rodents must consume the bait for several consecutive feedings to consume a lethal dose.

“This is because coumatetralyl is rapidly metabolised after ingestion.

“The outcome is still the same as single-feed rodenticides – with death occurring about three to eight days later ²– but very low levels of residues remain in the carcase.

“In fact, one experimental study found the ingestion of one baited rat posed no risk of poisoning in a healthy dog. ³

“Obviously that risk can increase with successive ingestion but it’s highlyunlikely.”⁴

Racumin Rat and Mouse Paste is packaged in highly palatable sachets that can be placed in hard-to-reach, undercover areas, such as ceiling voids or behind appliances. 

The sachets are ideal for use in a range of domestic and industrial situations, including around farm buildings and dairies.

Racumin Rat and Mouse Paste is available in 500g, 2kg and 5kg pack sizes.

Racumin Rat and Mouse Blocks are weather-resistant, soft wax blocks that can be placed in bait stations in areas of known rodent activity.

They are also registered for use in rodent control programs in field crops, such as macadamia, sugar cane and pineapple plantations.

Racumin Rat and Mouse Blocks are available in 5kg packs.

Racumin 8 Rat and Mouse Rodenticide is a dry concentrate powder that can be sprinkled on areas of known rodent activity.

Rodents ingest the powder when grooming their feet and fur.

Racumin 8 can also be mixed with a suitable bait material, such as grain or fruit.

Racumin 8 Rat and Mouse Rodenticide is available in 1kg and 10kg packs.

Each Racumin formulation contains Bitrex, a bitterant that deters accidental ingestion by humans.

Kim says all rodenticides should be used as part of an integrated management program for optimal control.

“Plan your rodent control program early in the season and select the most appropriate product and formulation type for your situation,” she says.

“Minimise access to feed sources as much as possible and clean up any feed spills.

“Good weed management around infrastructure and in surrounding paddocks will discourage the use of these habitats by rodents and expose them to predators.

“Monitor for any signs of infestations, such as droppings, gnawing or burrows around feed sources, runways, vegetation and buildings.

“Commence your baiting program at the earliest opportunity and continue baiting for at least two weeks to prevent the population from building into plague proportions.”

To learn more about Racumin or other Elanco animal health solutions, please contact our Customer Service team or visit www.farmanimal.elanco.com/au

References:1. Lohr, M.T. et al. (2025). Widespread detection of second generation anticoagulant rodenticides in Australian native marsupial carnivores. Sci. Total Environ. 967(01/03/25), 178832. 2. Baiting for at least two weeks is necessary to eliminate rat or mouse numbers. 3. Berny. P.J. et al. (1999). Evaluation of the secondary toxicity of coumatetralyl to dogs and an example of rat control in a dogs’ boarding kennel. Proceedings of the 3rd International Conference on Urban Pests. 4. All animals can be poisoned if they feed on sufficient bait directly. In the event of accidental ingestion of a baited rodent by a domestic animal, veterinary advice should be sought immediately.