Poisoning of feral pigs with sodium nitrite (HogGone)

Standard Operating Procedure – Under development

HogGone is currently available as a manufactured bait from Animal Control Technologies Australia – https://animalcontrol.com.au/products/hoggone and it needs to be used in conjunction with the HogHopper bait delivery system – https://animalcontrol.com.au/products/hoghopper-bait-delivery-system.

View our FAQ below for more information on HogGone. Details about its use will be available on PestSmart soon.

Frequently asked questions about HogGone

What is ‘HOG‑GONE®’ and how does it work?

HOG‑GONE® is a next-generation feral pig bait, designed for broad‑scale control and management of feral pigs. Fast‑acting and highly toxic to pigs, the active compound in HOG­­­­­­­‑GONE® is sodium nitrite — a common human food preservative — which acts by blocking oxygen-binding pathways in the pig. This mode of action is far more humane than existing baiting systems and sodium nitrite toxicity is potentially reversible. An antidote, methlyene blue, is currently being investigated.

Reference

  • Cowled et al. (2008). Additional toxins for feral pig control: identifying & testing Achilles heels. Wildlife Research 35:651-662

Is sodium nitrite really more humane than existing feral pig baits?

Yes. According to independent testing (www.imvs.sa.gov.au/), sodium nitrite satisfies the general criteria for a humane poison — it is rapid and the symptoms leading to death are generally unremarkable. Sodium nitrite works very quickly in the pig, resulting in unconsciousness and death within about two hours. This is a much shorter timeframe than other toxins currently or previously used for feral pig control in Australia such as warfarin (1–2 weeks), phosphorus (yellow phosphorus or CSSP; 2–4 days) and sodium fluoroacetate (1080; 6–8 hours). Sodium nitrite does not cause severe clinical disease with high levels of distress. The mode of action is similar to carbon monoxide poisoning, with sodium nitrite intoxication leading to a state of unconsciousness before death.

Reference

  • Institute of Medical and Veterinary Science (IMVS, 2010) Assessing the humaneness and efficacy of a new feral pig bait in domestic pigs.

 

Isn’t nitrite a strictly controlled substance?

No, sodium nitrite is already used in the food industry as a common meat preservative. Sodium nitrite should not be confused with sodium nitrate, which is far less toxic and not practical for feral pig control. A patent has been granted on the use of sodium nitrite as a vertebrate pesticide, so only IA CRC/ACTA licensees can manufacture nitrite-based vertebrate pest products.

Can I use standard meat preserving nitrite for feral pig control?

No. Standard meat preserving nitrite should be avoided as it is unlikely to kill and would probably compromise future pig baiting programs in the area. Although meat preservatives and curing agents contain sodium nitrite, the percentage of nitrite is too low to be toxic to feral pigs. Some preservative mixtures contain less than 1% sodium nitrite, with the rest made up of regular salt. Feral pigs find salt unpleasant and can develop a strong aversion to baits that have a salty taste. The sodium nitrite in HOG‑GONE® baits is microencapsulated to avoid issues such as bait aversion, and to maximise stability and gut delivery to the pig.

Reference

  • Siu & Henshall (1998). Ion chromatograhic determination of nitrate & nitrite in meat products. Journal of Chromatography A. 804:157-160.

What about availability and operator safety of HOG‑GONE® baits?

The classification level of HOG‑GONE® baits will be lower than currently available pig toxins, which means reduced hazard for operators and greater availability in most states and territories. HOG‑GONE® baits are likely to be classified Schedule 6 (S6) under the Standard for the Uniform Scheduling of Medicines and Poisons5 (SUSMP) and the Agricultural and Veterinary Chemicals Code Regulations. S6 chemicals are available to the public, but containers must include the heading, ‘Poison’. Due to their moderately hazardous nature, direct contact with S6 chemicals should be avoided. It is recommended that HOG‑GONE® baits be handled with tongs, which also provides the added benefit of reducing human scent on the bait.

Can I eat the meat from pigs that have been poisoned by HOG‑GONE® baits?

Yes. There is no possibility that a human or any other animal could receive a lethal nitrite dose from eating muscle tissue from HOG‑GONE® poisoned feral pigs. You are more likely to find higher levels of nitrite in your average vegetables (57 mg/kg) and cured meats (100 mg/kg) than in the muscle of nitrite-poisoned feral pigs (2–6 mg/kg). However, consumption of undigested stomach contents should be avoided as they may contain intact bait material.

References

  • Hord et al (2009). Food sources of nitrates and nitrites. American Journal of Clinical Nutrition. 90(1):1-10.
  • Correia et al (2010). Contribution of different vegetable types to exogenous nitrate & nitrite exposure. Food Chemistry 120(4):960-966.

 

Someone said that sodium nitrite causes cancer. Is this true?

There is no evidence of a cancer risk from the sodium nitrite used in feral pig baits. Authorities in toxicology and food safety have deemed nitrites safe to eat when used appropriately. Public health benefits of nitrite use far outweigh potential risks, with the addition of nitrites to certain foods essential for the prevention of spoilage and food‑borne disease such as botulism. In recent years health experts have questioned claims about nitrite links to cancer, especially as new studies point to possible benefits of nitrite consumption to cardiovascular health and blood pressure.

References

  • National Toxicological Program (2001). Technical Report on the Toxicology and Carcinogenesis Studies of Sodium Nitrite in Rats and Mice. US Dept of Health & Human Services.
  • American Meat Institute (2008). Sodium Nitrite: The Facts.
  • Food Safety Australia (2010). Nitrites – Good or Bad?

Has HOG‑GONE® been thoroughly tested?

Yes. HOG‑GONE® baits have been extensively tested both in the laboratory and controlled pen trials for stability, palatability, persistence of the toxin in the carcass/environment, efficacy and humaneness. Current field testing for national registration of HOG‑GONE® is nearly finished, and the baits have proven highly effective against feral pigs across a range of rural settings in Australia. Testing of non‑toxic versions of the bait is also well underway in the United States.

Are other animals at risk from HOG‑GONE® baits? What about my dog?

Livestock and native species are not usually attracted to HOG‑GONE® baits. However, individual animals may sample a bait, so it is recommended that non-target animals be excluded from baiting points by fencing or use of a HogHopper™. The HogHopper™ — a bait delivery device that targets feral pigs (pictured right) — has been developed with the management of populations of feral pigs in mind. The HogHopper™ design increases the selectivity, efficiency and safety of feral pig baiting. In areas where farm dogs have access to bait points, a HogHopper™ should be used.

How long does it take for HOG‑GONE® baits to break down?

HOG‑GONE® baits are designed to break down over time with the action of moulds and bacteria in the soil. Breakdown varies with temperature and soil moisture from about a week in wet tropical conditions, to two months in dry areas. While it is not essential to retrieve HOG‑GONE® baits from baiting sites, it is good practice to remove any excess bait at the end of a program.

How does HOG‑GONE® fit with other pig control techniques?

Toxic baiting is a broad‑scale management tool and the most cost-effective means of controlling feral pigs in Australia. On their own, HOG‑GONE® baits (with HogHopper™) have consistently reduced feral pig activity by 70–90% in field studies. Research indicates that using different control methods in a coordinated way is the best approach to remove pest animals and prevent damage. Landholders are likely to see long‑term benefits from an integrated approach to feral pig management that combines HOG‑GONE® baiting with other techniques such as shooting and trapping.

The authors of these documents have taken care to validate the accuracy of the information at the time of writing. This information has been prepared with care but it is provided “as is”, without warranty of any kind, to the extent permitted by law. The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the institutions the authors work for or those who funded the creation of this document.

FURTHER RESOURCES ABOUT BAITING

In this five-part series Jason Wishart discusses things to consider and what to look for when choosing a site to set up a bait station for feral pigs.

Part 1: Intro to feral pig baiting

Part 2: Jason describes how water-points can be used for pig control and looks at features

Part 3: Jason describes how signs of feral pig activity along roads and tracks can indicate good

Part 4: Jason demonstrates how to identify feral pig travel paths or pads for bait station sites.

Part 5: Summary and quick tips and tricks

Using the HogHopper as a delivery system? Jason discusses and demonstrates the use of the HogHopper® bait delivery device for feral pig control. Aspects such as assembly, site selection, pre-feeding and toxic baiting are covered.

 

Connect with Government

It is important to connect with the relevant government authorities to ensure you have the right permits in place prior to undertaking your management program.

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How to reference this page:

Centre for Invasive Species Solutions, 2011. Poisoning of feral pigs with sodium nitrite (HogGone). Factsheet. PestSmart website. https://pestsmart.org.au/toolkit-resource/poisoning-of-feral-pigs-with-sodium-nitrite-hoggone accessed 28-10-2020