Could a Newt Kill a Chicken?

Every now and then I run across a newt, either wandering in the backyard or curled up in some corner of the garden. Here in Tennessee I’m always delighted to spot a bright orange Eastern newt. It never occurred to me to wonder: Could a newt kill a chicken?

First, What’s a Newt?

Newts are a type of salamander. In contrast to the aquatic to semi-aquatic salamanders, mature newts are largely terrestrial. Where aquatic salamanders have webbed feet and paddle-like tails, newts have long-rounded tails and fingers designed for digging up yummy worms and insects.

Our colorful Eastern newt (Notophthalmus viridescens) ranges from southern Quebec to Florida and westward to Texas. The more drab rough-skinned newt (Taricha granulosa) lives along the Pacific Coast.

Aside from color, another difference is length. The Eastern newt is 2 to 5 inches long, from nose to tail. The rough skinned newt grows up to 7 inches long.

The powerful neurotoxin tetrodotoxin is one of the things these two lizard-like species have in common. Tetrodotoxin can cause paralysis when it comes into contact with the soft tissues of the mouth. The main function of tetrodotoxin is to provide a defense against predators.

Tetrodotoxin is produced by various bacteria of the pseudomonas species and is concentrated in glands in a newt’s skin. When the newt is attacked, it squeezes the glands to force out the toxin. The unfortunate predator with the newt in its mouth can die rapidly. To date no antidote has been found.

Dr. Beth’s Newt Story

My friend Beth Valentine is a veterinary pathologist retired from Oregon State University College of Veterinary Medicine. Her focal interest is diseases of the muscles and nerves. She’s also a chicken keeper.

“I had 6 black sex-linked hens that will be 2 years old in April,” she says. “I really wanted only 4, but I bought more assuming something would happen to at least one of them. Well, it finally happened.

“I went out to give the hens a treat, and they all came to me. But one was clearly and suddenly not right — tail drooping, sitting sternal. When she did stand, her legs shook, showing how weak she was. And she kept gaping with her beak. Not gasping, just gaping.

“It was late afternoon and I had to go out, so I put her in the coop. She was dead the next morning.

I first assumed hypocalcemia. But I thought that was weird, since all the food I give has calcium, including the oyster shell they have available. But, hey, they are free range so maybe she wasn’t eating what was good for her.

“Turns out I think that was really true.

Did the Newt Kill the Chicken?

“So I did the postmortem and she was in great body condition. She was just coming out of the molt and had plenty of internal fat. She had an active ovary, but wasn’t egg bound. I could find nothing wrong. All the rest of the birds were (and still are) just fine.

Then I remembered that a day or two before, I’d been walking up the gravel driveway and stopped to pick up a rough skinned newt. It was in the middle of the driveway and I thought I’d move it so it didn’t get run over. Turns out it was dead and rather desiccated, but the skin still intact.

“I thought about throwing it into the bushes where a chicken couldn’t eat it. But then I thought it was too disgusting for even a chicken to eat and left it there. Likely a bad decision!

“After posting the hen, I walked back to the driveway and the newt body was gone. Bird droppings were in the area, but they had been flattened by traffic. So I couldn’t be sure if they were chicken or wild turkey droppings.

“I had looked in the hen’s crop and ventriculus, where I found disgusting brown content. With what chickens eat, that’s often the case.

“But my working hypothesis is that she ate the newt body. With just skin, it would have had a high concentration of tetrodotoxin, and the hen would have died soon afterward. Of course, I have no absolute proof, but the scenario makes the most sense.

“On our property we have ponds that are loaded with newts. We occasionally see them wandering around our property, so the risk is still there. In the future I will dispose of any newt bodies I find!”

No Real Proof, But…

Dr. Beth and I both looked for reports of chickens being poisoned by newts, but we found scant information. We did find a paper indicating that chickens are potentially sensitive to tetrodotoxin, and an old report on tetrodotoxin toxicity in birds in general.

So, could a newt kill a chicken? You bet! If I ever spot a newt wandering anywhere near my chicken yard, I will rescue it before the chickens use it for a tug-of-war.

Oh, and chickens aren’t the only ones potentially sensitive to tetrodotoxin. If you ever have occasion to handle a newt, dead or alive, wash your hands well. And whatever you do, don’t touch your mouth. Otherwise you may feel an alarming sense of numbness in your fingers and lips.