Despite efforts by all parties concerned to reduce the risk of accidental poisonings by improving product labels, packaging and use patterns, such incidents continue to occur. The US Environmental Protection Agency now requires rodenticides marketed to consumers to be pre-packaged with tamper-resistant bait stations , which is expected to significantly reduce the potential for exposure to both children and pets. The new EPA rules also limit the types of rodenticide that may be sold to consumers, which is intended to further reduce the risks to children and pets, and also the potential risk to non-target wildlife from primary exposure (direct eating of bait) or secondary exposure (feeding on poisoned or dead rodents). Even with these precautions, veterinarians will continue to play a vital role in case diagnosis and saving animals exposed to rodenticides.
Recent work indicates that multiple exposures to anticoagulant rodenticides, over the course of multiple days, result in greater toxicity than is reflected by the standard single-dose acute oral toxicity LD50 test . Veterinarians should consider this factor, especially for secondary exposure to dogs, cats and wildlife. Even though the amount of rodenticide contained in a poisoned rodent is small, repeated consumption over a prolonged period may result in toxicity to the predator or scavenger.
This guide is intended to help veterinarians understand the differences in toxic action between the various active ingredients. Two case histories are provided to describe the different courses of action and management of poisoning incidents involving different anticoagulants. These case histories also point out the potential importance of determining, whenever possible, the type and quantity of the anticoagulant consumed, the time of consumption and the health of an animal prior to anticoagulant ingestion. Based on these case histories, recommendations are made for treating animals exposed to various anticoagulants. In addition, guidelines are given for informing pet owners of the likely costs involved in treating an exposed animal and of the role they can play in helping the animal recover. Tables 1 and 2 compare the acute toxicities of first- and second-generation anticoagulant rodenticides for dogs and cats. A table is also included outlining recommendations for treatment of rodenticide poisoning. This edition includes updated active ingredient trade names in the tables and corresponding footnotes to better reflect brands now found in the marketplace.
Preparation of the first edition of the ‘Vet Guide’ would not have been possible without special input from W. Jean Dodds, D.V.M. and Stephen C. Frantz, Ph.D. who served as Chief of Laboratory of Hematology and Rodent & Bat Specialist, Wadsworth Center for Laboratories and Research, New York State Department of Health (NYSDH) respectively at the time of these studies. Dr. Dodds received many awards for excellence in the field of veterinary medicine and has published more than 150 papers in the field of blood disorders. Dr. Frantz conducted research and taught rodent behavioral ecology and integrated pest management in the United States and abroad. He was technical consultant for Center for Disease Control's (CDC) Federal Rat Evaluation Laboratory. Drs. Dodds and Frantz have also conducted research on poisoning of animals by anticoagulant rodenticides; the clinical data and recommendations reported here are drawn largely from their work.
We also wish to express our appreciation to those people who have reviewed this guide and for their valuable comments, including R. O. Baker, R.A. Green, P.L. Hegdal, W.W. Jacobs, R.E. Marsh, M.E. Mount and V. Perman. Special credit is due Keith Story for his overall guidance and editorial input. We’d also like to acknowledge Dr. Cheryl Roge for her expertise and assistance with the most recent updates to this guide.
Liphatech, Inc. has sponsored the production of this guide as a service to veterinarians. As a leading developer and marketer of first- and second-generation anticoagulant rodenticides, as well as other rodent control products, we are committed to helping achieve effective and safe rodent control worldwide. By providing this information to veterinarians, we hope it will help maintain the good safety record, not only for our innovative rodenticides, but for all anticoagulants. While veterinary skills, if applied in time, can prevent most animal deaths, we recognize our responsibility to continue product improvements and user education aimed at minimizing exposure incidents. We thank everyone who, through their guidance and research efforts, made this guide possible.