Growing up, Michael Slusher loved animals. He had pet rats, lizards, and the typical dog and cat. So when he decided to combine that affinity with his love of science and make a career out of it, he thought it was the best of both worlds. But he didn't know that would lead him down a path he now regrets.

Slusher's first job out of high school seemed innocent enough.

He was paid to record the weights of rats for a lab that was doing animal research. But soon he was trained to do other tasks, like injecting the rats, and eventually euthanizing them by asphyxiating them with carbon dioxide.

"It did impact me emotionally. I mean I do not like killing anything and I didn't then either," he told Out in the Open host Piya Chattopadhyay.

Slusher said he bought into the view promoted by his supervisors and believed the work they were doing would make a difference.

We're here doing these things for the greater good of humanity, and by sacrificing some animals maybe we're going to ease suffering or illness in humans. And so that kind of the ends justify the means was the modus operandi. - Michael Slusher on how his employers justified testing on animals

Despite believing in the goal of the research, he said there were things that disturbed him.

"It always distressed me if we had either ordered the wrong animals, the wrong strain and they had to be disposed of. So if there is waste of animal life where they weren't used at all that kind of distressed me. It was almost like it was okay to kill them as long as it was for a reason."

Eventually, Slusher was also tasked with euthanizing dogs and monkeys and he said it was hard not to make attachments.

"When you're dealing with pet animals that are typically associated with your home and friendship that brings in a whole new level."

Friends, not food

Slusher spent seven years working in animal research at two different labs, but eventually had a change of heart and moved to a farm in Arizona.

He found himself raising alpacas because his wife is a fibre artist and uses the wool for her art. Slusher learned not to go around them after eating meat because they would view him as a predator.

Michael A. Slusher is the author of They All Had Eyes: Confessions of a Vivisectionist (Courtesy of Michael A. Slusher)

"That really struck me as odd because I never considered myself as anything but benevolent to these animals. I wasn't going to kill them. I wasn't going to attack them."

This made him question everything.

"That really kind of made me stop and think, wait a minute. What is my position here [to] these animals and how do you reconcile that?"

It wasn't just the alpacas that made Slusher wonder about his previous work.

It was the friendly cow that would always come running up to see him and lick his hand. And the chickens that flew up on his shoulder and then nuzzled against his cheek.

Slusher began realizing that his past work euthanizing animals was starting to haunt him.

"I began having nightmares about laboratory animals. For example, [in] one there is a rabbit just laying on a counter and as I approached it, he rolled over and his intestines and guts just spilled out on the table. Other dreams involve being chased down hallways by hundreds of rats and mice."

Reliving the past to help animals in the future

Eventually, Slusher realized he didn't want to be involved with hurting animals ever again. He went vegan, and now speaks out against animal research, calling it ineffective and wasteful.

"It has a very high failure rate on new drugs that are being tested on animals and it's almost like throwing spaghetti at the wall to see what sticks."

Slusher said he feels research is advancing to a point where animal testing is no longer necessary, with alternatives like computer modelling, or microchip testing.

"New technologies are exploding such as organs on a chip where they can test toxicity of the liver by putting some of this on literally a computer chip."

Slusher has since shared his concerns in his book They All Had Eyes: Confessions of a Vivisectionist. While he has received support from the animal rights community for speaking out, he said sharing his story hasn't always been easy.

"When you have a name and a face of somebody who actually did the hands-on bloody work it makes a lot easier to express their anger."

He hopes that one day all animals will be treated fairly.

"That whole idea that humans are kings of their dominions and can treat any other natural resource as just that, just some kind of resource, really flies in the face of of anything moral about how we treat creatures who suffer."

Slusher said when it comes to animal research, he thinks the ends do not always justify the means.

"We don't kick our dogs at home. Most people aren't abusing animals in labs maliciously either. But for some reason we have no problem making the disconnect between laboratory animals and the animals at home."

This story appears in the Out in the Open episode "Done and Done".