By Stella McMillin
Lake Tahoe Wildlife Care called our lab over the weekend to report they had a coyote that had been found wandering in Strawberry, which is in El Dorado County. The veterinarian there examined the coyote and found unexplained bleeding around his mouth, which, when unaccompanied by signs of trauma, can indicate poisoning from a kind of rodenticide that thins the blood.
Anticoagulant rodenticides are a tough issue right now. They are legal, widely used, and few users know the impact they can have on wildlife. Predators and scavengers get exposed to rodenticides when they eat rodents that have been poisoned.
The veterinarian drew blood and confirmed that coyote’s blood clotting was impaired. The coyote did not recover and was subsequently euthanized.
From Strawberry, the coyote was brought to our lab by Tom, the rehabber. The necropsy went as expected – lots of blood, both under the skin and loose in the chest and abdominal cavities. There were no broken bones. It appears that the animal was bleeding to death internally.
We took liver tissue for our chemistry lab to examine. Monitoring studies reveal that the majority of predatory and scavenging wildlife in California are carrying residues of anticoagulant rodenticides in their livers.
DFG would like to see the more persistent and toxic of these rodenticides restricted so they could be used only by certified applicators. It is one measure we can take to reduce our impact on wildlife in California.
For more information on rodenticides, see http://www.dfg.ca.gov/education/rodenticide/.
As the person who monitors pesticide impacts to wildlife in California, I am often grateful to the wildlife rehab volunteers. They are often the ones who call our attention to poisoned wildlife and will sometimes go the extra mile, as Tom did, to drive the coyote over to our lab so we can work on it. This is particularly true in the case of the anticoagulant rodenticide issue, where many of the animals we have diagnosed have been brought to us through wildlife rehabilitation centers.
I’ll post chemical results when we get them back from the lab.