Other names
Vitamin D3, activated 7-dehydricholesterol
Development and use
Cholecalciferol is produced industrially for use in vitamin supplements and to fortify foods. In the 1970s, rodents were found to be more susceptible to high doses than other animal species and, as a result, cholecalciferol was used in rodenticide products combined with warfarin and by itself (Lund, 1977). It has been used to control rodents in the USA since the 1990s (Witmer et al., 1995) and to control brushtail possums in New Zealand since 1995 (Eason and Wickstrom, 2001).
In Australia, cholecalciferol is used to control rats and mice, particularly anticoagulant-resistant strains. For poultry operations, it can be used in and around structures and along perimeter fence lines. Despite its lower risk of contamination and residues, its use is not advised in ranging areas or inside bird housing sheds (BASF, 2018).
Mode of action
Within 14–48 hours, poisoned rodents stop eating, and become lethargic, weak, dehydrated and anorexic. Cholecalciferol poisoning causes hypercalcemia (excessive blood calcium levels), which causes calcification of blood vessels, soft tissues and organs. Death can occur from any of the following causes or a combination: kidney, heart or respiratory failure; or haemorrhaging from the calcification of blood vessels and internal organs (Dorman and Beasley, 1989; Peterson et al., 1991).
In rodents, death can occur from a single large dose or multiple smaller doses in which the compound accumulates a lethal dose faster than it is metabolised (see Acute toxicity). Cholecalciferol is metabolised in the liver and kidneys, producing calcitriol, the most active form of vitamin D3 (Dorman and Beasley, 1989). Sub-lethal doses of cholecalciferol and its metabolites persist in the adipose tissue (fat) of rats, with a half-life of 81 days (Brouwer et al., 1998). Because birds are less susceptible to cholecalciferol than rodents (McLeod and Saunders, 2013), they are a minor secondary poisoning risk. Dead or dying rodents should still be cleared from production areas as soon as possible to prevent disease transmission.
Time to death
- Rats: 2–11 days (Greaves et al., 1974 & Lund, 1974)
- Mice: 3–21 days (Hatch and Lanflamme, 1989)
Evidence of resistance
There is no evidence of resistance.
APVMA-registered products containing cholecalciferol
Selontra® (0.75g/kg), Rampage® (0.75g/kg)
Available formulation
- Pellet bait
- Soft bait
Acute toxicity
| Species | LD50 | Average bodyweight | Amount of bait consumed for a LD50 | Reference (for LD50) |
|---|---|---|---|---|
| Mouse | 42.5–136.4mg/kg | 20g | 1.1–3.6g* | Marshall, 1984 |
| Norway rat | 43.6mg/kg | 320g | 18.7g* | Marshall, 1984 |
| *Calculated using a bait concentration of 0.75g/kg | ||||
An adult rat (bodyweight of 320 grams) will eat about 20–30 grams of food daily; an adult mouse (bodyweight of 20 grams) will eat 2–5 grams of food daily (Hadler and Buckle, 1991). Cholecalciferol rodenticides have a standard active concentration of (0.75g/kg).
Therefore, 18.7 grams of bait would be considered a lethal dose for rats and 1.1–3.6 grams of bait lethal for mice. For both species, this is within the daily food requirement but on-farm, where rodents have other food sources, repeated bait feeding is likely to be needed to ensure effective control.
Poison schedule and regulatory requirements
Cholecalciferol is classified as a Schedule 7 Dangerous Poison and is available only to specialised or authorised users. Regulations restricting their availability, possession, storage or use may apply. Please check with your state health authority before purchasing.
Handling, storage and user safety
Bait should be securely stored in its original container in a cool, well-ventilated area, out of direct sunlight and away from sources of heat.
Disposable gloves are recommended when using products containing cholecalciferol. Avoid contact with eyes and skin; wash hands, arms and face thoroughly with soap and water after use.
Read the label before use. For detailed instructions on handling and user safety, please refer to the relevant Safety Data Sheet.
References
BASF Australia Limited. (2018). Selontra® Soft Bait Rodenticide – An Innovative Solution for Rodent Control in Poultry Environments. https://crop-solutions.basf.com.au/files/product/E9K6uENGfWLh4sfb.pdf
Brouwer, D. J., Van Beek, J., Ferwerda, H., Brugman, A. M., van der Klis, F. R., van der Heiden, H. J., & Muskiet, F. A. (1998). Rat adipose tissue rapidly accumulates and slowly releases an orally-administered high vitamin D dose. British Journal of Nutrition, 79(6), 527-532.
Dorman, D. C. and Beasley, V. R. (1989). Diagnosis of and therapy for cholecalciferol toxicosis. Pages 148-152. In Current veterinary therapy X. Small animal practice. WB Saunders, Philadelphia, USA.
Eason, C. T. and Wickstrom, M. (2001). Vertebrate pesticide toxicology manual (poisons). Department of Conservation Technical Series 23. Department of Conservation, Wellington, New Zealand.
Greaves, J. H., Redfern, R. and King, R. E. (1974). Some properties of calciferol as a rodenticide. The Journal of Hygiene, 73:341-351.
Hatch, R. C. and Laflamme D. P. (1989). Acute intraperitoneal cholecalciferol (Vitamin D3) toxicosis in mice: its nature and treatment with diverse substances. Veterinary and Human Toxicology, 31:105112.
Marshall, E. F. (1984). Cholecalciferol: a unique toxicant for rodent control. In Proceedings of the Eleventh Vertebrate Pest Conference, 22. 95-98.
McLeod, L., & Saunders, G. (2013). Pesticides used in the management of vertebrate pests in Australia: A review. NSW Department of Primary industries.
Lund, M. (1974). Calciferol as a rodenticide. International Pest Control, 16:10-11.
Lund, M. (1977). New Rodenticides Against Anticoagulant‐resistant Rats and Mice 1. EPPO Bulletin, 7(2), 503-508.
Peterson, E. N., Kirby, R., Sommer, M., & Bovee, K. C. (1991). Cholecalciferol rodenticide intoxication in a cat. Journal of the American Veterinary Medical Association, 199(7), 904-906.
Witmer, G. W., Matschke, G. H., & Campbell, D. L. (1995). Field trials of pocket gopher control with cholecalciferol. Crop Protection, 14(4), 307-309.
