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 six-month-old intact Doberman Pinscher female was admitted to a veterinarian's office with a swollen stifle. X-rays revealed only a soft tissue swelling. However, epistaxis began the next day and continued until the hematocrit had dropped to 13%. The owner indicated that on searching the area where the dog usually exercised, small amounts of material like warfarin were found. A local rancher admitted to placing the toxicant in the surrounding area to control rodents in the past few days, and the dog's owner failed to keep the dog confined to his own property.
Upon admission but prior to the onset of clinical signs obviously referable to bleeding, the veterinarian should:
In the specific case described here, the animal's clinical signs were more severe than would be expected by exposure to a standard warfarin product. The clue comes from the fact that the patient is a Doberman Pinscher, a breed known to have a high prevalence (50%) of von Willebrand's disease (VWD), an inherited bleeding disorder, as well as hypothyroidism, which also produces a bleeding tendency . Thus the animal should be blood tested for both VWD and thyroid function. As it turns out, many of the recently studied rodenticide poisoning cases involving Dobermans kept as guard dogs and allowed to roam free also had VWD, which aggravated their clinical course upon rodenticide ingestion . Prompt treatment with vitamin K1, whole blood transfusions and thyroid supplementation if needed, is especially important in such cases.
The above situations emphasize certain breed susceptibilities to complications arising from poisonings or low-dosage exposures which might otherwise be of little consequence. Another example is with whippets and greyhounds, two breeds known to have an overall lower tolerance to toxicants. The physiological and health status of the animal (e.g. estrous, pregnant, pseudo-pregnant, hypothyroid, debilitated, geriatric, etc.) at the time of exposure can also contribute significantly to the severity of signs and outcome of the case.