Carl and Lauren hoisted the dead deer into the refrigerated box on their truck and then picked up the rest of the dead animals scattered over Bill’s farm. Carl noticed that other than decomposition, the animals all looked in pretty good shape—they weren’t skinny or gaunt. He proceeded to take some soil samples from near where the animals were found.
“Do you think they were poisoned?” asked Lauren.
“I don’t think their food was poisoned, because they all have different food sources—deer eat leaves and grains, ducks typically feed in the water, raccoons are omnivorous, and coyotes are scavengers,” replied Carl.
Lauren knew that even if the animals were poisoned, they would need some clues on what type of poison to look for and in what body tissues. You can’t just test an animal for every possible poison.
Carl said, “Let’s look around, though I have a hunch. Poisoning is actually at the top of my list right now.”
Lauren wondered out loud what made Carl think that the animals might have been poisoned, even after he said he didn’t think it was in their food. Lauren remembered hearing something about naturally occurring anthrax being found in some soils… but then how would ducks fit into that?
Carl gave a garbled response about some patterns and about climate. Lauren was curious.
Carl and Lauren took a walk around the property and took notes. Along the way, Carl and Lauren discussed data they might want to gather. Lauren was curious about the direction Carl was going in. First, Carl told Lauren they should get climate data for the last few weeks, specifically rainfall and wind. As they walked around, Carl mentioned to Lauren that Bill had said the only water source was a pond, and that’s where they were headed.
The pond wasn’t much to look at. Water levels appeared to have dropped, and there was no stream inlet. It looked like the water had been stagnant for a while, and there was a surface film at one end of the pond. They took some water samples and headed back to the truck.
They stopped off at the farmhouse to see Bill. “Well, I’ve got a strong hunch I know what the problem is. We’ll know for certain within a few days. In the meantime, sit tight and let us know if any more dead animals pop up,” Carl told Bill.
“Do you think someone has been poisoning the water?” asked Bill.
“No, not exactly. I can’t say more on just a hunch, but I’ll bet a Philly cheesesteak that I’m right. You’ll hear from us by the end of the week,” replied Carl.
By now Lauren was very curious. As they were getting into the truck, she asked, “So what do you think, Carl?”
Carl smiled and said, “No, what do you think?”
“OK,” Lauren said. “No external wounds, so they weren’t shot. There aren’t many infectious diseases that can cross species boundaries like that, and there haven’t been reports from other areas. So it sounds like it’s something very local. They probably ingested something—probably not food, because they eat different things. Maybe water?”
“Alright,” said Carl. “It could be someone dumping something into the water to poison animals, but that’s pretty conspiracy-theory. It might be something seeping in, but I don’t think there’s ever been industry around here, there’s no pesticide storage around, and I don’t think the pond is spring fed. So if there is something in the water, it’s being produced in the water. Let’s change gears. What do you know about how toxins can act?”
Lauren was getting to the limits of her knowledge here. Even though as a vet she dealt with a few dog and cat poisonings, the owner always knew what the substance was, which made treatment easy.
“Uhhh, well, there are hepatotoxins, neurotoxins, toxins that act on cell membranes…. Some can act over a lifetime, some act almost immediately.”
“OK, good start. About the time-scale…. Do you think these animals were affected for many weeks, days, or pretty quickly?”
“Uhhhh, I don’t know. Wait. As we put the animals in the truck, they seemed in really good shape. The raccoon was fat and the deer looked in really good condition. They probably weren’t sick for long, so I would say it was quick. Plus, Bill didn’t find any dying animals, just dead ones. That also suggests a quick death.”
“Excellent, Lauren. So what kind of toxin might act quickly?”
“Neurotoxins can act fast.”
“Yep, that’s what I’m thinking too. So to understand how neurotoxins work, we need to know how the nervous system works—anatomy and physiology. Let’s meet tomorrow for a review of the nervous system.”
Lauren sensed she had some work to do. When she got home that night, she pulled out her Anatomy and Physiology texts, and made an outline of the things she needed to know.
Originally published at http://www.sciencecases.org/hot_august/hot_august.asp
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