Vet Guide: Case Study I
The following case studies taken from the files of the Laboratory of Hematology of NYSDH exemplify two common scenarios with respect to anticoagulant rodenticide poisonings and have been summarized in Table 3. Diagnostic and therapeutic regimes reflect a composite of inputs including foreign sources [refer to endnotes 17, 38, & 45.]
A three-year-old, spayed female terrier was admitted to a veterinarian's office because of recent clinical signs of occasional bleeding from the gums accompanied by the presence of black, tarry stools. On questioning the owner, there had been no previous history of a bleeding tendency and no known exposure to anticoagulant rodenticides or other toxicants.
Course of Action:
The referring veterinarian in considering the history, rules out the likelihood of a congenital coagulation defect because the animal was spayed uneventfully and had no previous history of excessive bleeding. Suspecting rodenticide toxicosis, the veterinarian has two courses of action to recommend:
The preferred option involves collection of blood samples to perform routine hemograms and coagulation profiles, plus immediate treatment with vitamin K1 and blood transfusion(s), if the latter are needed to control bleeding. Once laboratory data is available, vitamin K1 treatment can cease if results rule out anticoagulant rodenticide exposure. As the time from ingestion of rodenticide to sampling is unknown in many confirmed cases, treatment should continue for 4-6 weeks to control the long-term effects of the more toxic first- or second-generation anticoagulants.
The alternative option, when costs are a factor for the client, is to initiate and maintain treatment without confirmatory laboratory data. This is less desirable because the suspected diagnosis cannot be confirmed, thus failing to provide adequate documentation should it be needed, and treatment must be maintained for 4-6 weeks in the absence of serial monitoring for the reasons stated above.