Another Victim of Rat Poison?

September 17, 2015 Posted by: Kate Kuykendall, Public Affairs Officer

A local resident discovered this gray fox and reported it to our biologists. | Photo: National Park Service

A local resident discovered this gray fox and reported it to our biologists. | Photo: National Park Service

When the National Park Service released an image that showed the famous Griffith Park mountain lion known as P-22 suffering from mange and disclosed that he had been exposed to rat poison, biologists hoped the unfortunate news would raise awareness about the harmful impacts of common household poisons on our local wildlife population. 

This week’s report of a dead gray fox brought home how far we have to go in educating the community about the unintended impacts of using these products around homes, parks, and businesses.

A local resident called on Monday to report the dead animal, found on private land near Peter Strauss Ranch in Agoura. Although the findings are still preliminary, the necropsy indicated that the gray fox likely died as a result of exposure to anticoagulant rodenticide (this is the more formal term for the rat poisons that use blood thinners to kill the animal). The gray fox had internal bleeding and did not have any signs of other trauma (such as injury from a vehicle, other animal, etc.). Testing the liver for poison residues will help confirm the cause of death.

National Park Service researchers have documented widespread exposure to anticoagulant rodenticides since they began studying carnivores in and around the Santa Monica Mountains in 1996. The graphic below summarizes this research and shows how the poison works its way up the food chain.

Infographic: Rat Poison and Local Wildlife

Despite the fact that we’ve only studied a limited number of gray foxes, this is not the first time we’ve documented the poisoning of a local gray fox. Back in 2008, biologist Joanne Moriarty conducted a necropsy on GF-29 (the “GF” stands for gray fox), an animal she had first caught near Westlake Village. 

In that case, the animal had such significant internal bleeding that blood was actually coming out of its ears and mouth (anticoagulants block the vitamin K cycle, which is critical for allowing the body’s blood to clot).

GF-29’s ear shows signs of external bleeding and bruising. Anticoagulant rodenticides interfere with blood clotting. | Photo: National Park Service

GF-29’s ear shows signs of external bleeding and bruising. Anticoagulant rodenticides interfere with blood clotting. | Photo: National Park Service

Although these photos and details can be disturbing (and these are the sanitized photos that do not show blood throughout the abdominal cavity and elsewhere), it’s critical that the public understands the unintended consequences of using these poisons.

So please share this blog post with others and learn about controlling rodent populations without the use of anticoagulant rodenticides.

Although we think P-22 has recovered, it’s likely that he continues to be exposed to poisons left out by local residents and other property owners. 

Let’s see what we can do to change that.

6 Comments Comments icon

  1. October 22, 2015 at 10:07

    @Erik Knutzen: Generally speaking, we've found both first and second-generation anticoagulant rodenticides in the animals we've tested. As to the exact cause, I think there is no shortage of both homeowners leaving poisons out near their home and also homeowners or property management companies that hire exterminators to do the same. I don't think most people understand the unintended consequences from these actions. We are still waiting for the toxicity results of P-34. I don't think we've ordered those results for this fox because he was not one of our study animals. This infographic sums up what we've found and the compounds you should look out for: -Ranger Kate

  2. October 20, 2015 at 12:40

    I'm curious if you know if this fox or the mountain lions that recently got poisoned were victims of second generation rodenticides or first generation poisons. Do you know the chemicals involved? Is this the result of the work of an extermination company or homeowners using off the shelf poisons?

  3. September 18, 2015 at 11:09

    Rat poison should be illegal.

  4. September 18, 2015 at 05:27

    Chuck, we no longer do. That was the last one.

  5. September 18, 2015 at 10:26

    My 11+ year old Lab, my service dog, became very ill a few months ago. She had thrown up a twistie tie, so the vet thought maybe she had an obstruction, perhaps a loaf of bread was missing? Following x-rays and a few tests, she found rat poison in her system. She didn't survive. The only time she was ever off leash was on a local hiking trail we often went to. The only way she could have gotten rat poison in her is if she found someone's carelessly discarded garbage. People here use the woods/logging roads as if it were a dump and it has become a major problem. It's not the way I expected to lose my beloved Gracie-goo.

  6. September 17, 2015 at 03:16

    That's so sad! Beautiful animal. I didn't even know we had Fox in the area.

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Last updated: September 17, 2015

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