Rodenticide Ingestion in Swine03 April 2014
Delegates at the Centralia Swine Research Update 2014 heard about a project to assist veterinarians with the detection of and establishing possible withdrawal times for the rat and mouse poison, bromadiolone.
Accidental ingestion of rodenticides in hogs represents significant food safety concerns, animal welfare issues, as well as substantial economic losses to the producers, reported Ron Johnson and Robert Friendship of Ontario Veterinary College at the University of Guelph.
The emergence of rodent strains resistant to older or first generation anticoagulant rodenticides has spawned the development of more potent, second generation compounds such as bromadiolone, which increases the potential for toxicity following accidental ingestion and the adulteration of carcasses intended for human consumption.
The true incidence of bromadiolone exposures in hogs is not currently known.
Inquiries to the Canadian Global Food Animal Residue Avoidance Databank (CgFARAD), Ontario Ministry of Agriculture, Food and Rural Affairs, and Animal Health Diagnostic Laboratory (University of Guelph) regarding accidental ingestion of rodenticides in swine supports their increasing occurrence.
Additionally, reports of accidental rodenticide ingestion, or possible exposure, in swine usually involve hogs near market weight and include, most commonly, groups containing large numbers of hogs.
Information pertaining to exposure, tissue depletion and possible withdrawal times of rodenticides in suspected swine toxicities would provide substantial guidance to veterinarians and producers regarding animal disposition given the significant food safety concerns to the public and financial considerations to the producer.
The objectives of their study were:
- to validate a non-invasive detection test for bromadiolone using blood and faecal samples in swine and
- to determine tissue residue depletion and estimate withdrawal time of bromadiolone in swine.
Blood as well as faecal samples could be used, prior to slaughter, to identify suspected bromadiolone rodenticide toxicity in pigs.
Administration of a single oral low or high dosage of bromadiolone to hogs showed considerable accumulation in the liver with concentrations persisting for a prolonged period of time.
Administration of a single high dosage of bromadiolone to hogs also showed considerable accumulation in the muscle with concentrations persisting for a prolonged period of time.
Results of this study will provide veterinarians with a non-invasive (blood or faeces) bromadiolone detection system that may be used to rule out exposure of hogs to bromadiolone.
Results of this study may assist CgFARAD with establishing possible withdrawal times in hogs that are exposed to bromadiolone.
Johnson R. and R. Friendship. 2014. Rodenticide ingestion in swine: a project to assist veterinarians with detection and establishing possible withdrawal times. Centralia Swine Research Update 2014. I-5—I-7.