New research challenges the popular notion that all commercial breeding kennels are inhumane.
Candace Croney joined the faculty at Purdue University in 2011, thinking her job would focus on the welfare of livestock and poultry in Indiana. With bachelor's, master's, and doctoral degrees in animal sciences, her work until then had centered on sheep, cattle, and pigs. She'd even had the esteemed animal behaviorist Temple Grandin help shape her master's research project.
Croney's research has become the first of its kind in the world—and it's challenging our understanding of how dog breeding is being done.
Then came an email from a new colleague asking Croney to discuss animal welfare with some of Indiana's commercial dog breeders, the kind who produce large quantities of puppies for sale in pet stores.
"I didn't even know the term commercial breeders," Croney says. "I'd heard the term 'puppy millers.' That's pretty much what I knew."
She went to the first few kennels and braced herself for an upsetting experience. She's a dog lover who has fostered shelter mutts and owned one, and she'd seen the stories: large-scale breeders being called cruel and evil, lawmakers trying to ban the sale of commercially bred puppies, and constant encouragement to rescue a dog instead of paying into a greedy, heartless "puppy mill" industry.
But when she got to the kennels, she was surprised. While she encountered a number of things she didn't like about the infrastructure at the older facilities—a lack of ventilation, a lot of noise, bad smells—most of the dogs themselves were clean. The majority didn't have physical problems. No open sores. No battered bodies. Nothing like what she'd seen online.
But still, the way the dogs acted gave her pause.
"Things were, in many regards, better than I thought they would be," Croney says. "Google told me the dogs would be physically a mess, and they weren't, but behaviorally, things were jumping out at me."
While she did note that some of the breeders had play yards for their pups, a number of the dogs feared new people and things like leashes because they hadn't been exposed to enough of them. Some of the dogs also seemed to lack adequate toys, activities, and games to keep them mentally and physically stimulated.
But she was there strictly as a representative of the university to ask questions and offer feedback, no more or less. A few times, she says, she felt like the breeders wanted her to endorse what they were doing, "and I immediately got my back up about that. I did not want my name used to validate things that I could tell I didn't agree with. It was uncomfortable from that perspective."
After sharing the animal-welfare information her colleague had requested, Croney figured that was that. She never expected to be in a commercial kennel again. But six months later, her phone rang. Some of the people she'd met were involved in legislative lobbying, and they were trying to write welfare standards for Indiana's commercial breeders to follow.
In the continuing battle over what is, and is not, a "puppy mill," they wanted somebody with a strong research background to set a baseline standard, somebody who would actually bring objectivity to the breeder-activist conflict without being on one side or the other.
In other words, they wanted Croney's help to figure out not only appropriate enclosure sizes, but also requirements for socialization and enrichment activities—stimulation she knew the dogs desperately needed.
"I thought, crap, how am I not going to help?" she recalls. "And they said, 'Well how long will that take? A couple of weeks? A month?'"
Dr. Croney with Theo, whom she calls "a beloved family member of our research team."
(Photo credit: Purdue University/Vincent Walter)
Six years later, Croney's research remains ongoing. It has become the first of its kind in the world—and it's challenging our understanding of how dog breeding is being done, and how it could and should be done for years to come.
How We Got Here
Americans have been breeding pet dogs in large-scale kennels since World War II. The federal standard that regulates those kennels is the Animal Welfare Act, which President Johnson signed into law in 1966. Back then, people thought it was OK to treat dogs a lot differently than they do today. The law has been updated, but it still allows a dog the size of a Beagle to be kept in a cage the size of a dishwasher all day, every day because for some dogs, when the law was written, having a cage that size meant an improvement in living conditions.
Countless commercial breeders, who are regularly inspected under the Animal Welfare Act, have long believed that as long as they followed the law, they were doing things right. And they've seen sales for their puppies go up and up over the years. About 38 percent of U.S. households now own one or more dogs, the highest rate since the American Veterinary Medical Association began measuring the statistic in 1982.
Consumers now demand eight million dogs per year, which has reinforced breeders' beliefs that despite what activists shout at protests, the breeders are actually running businesses the public supports. As one Ohio commercial breeder—long decried by activists as a "puppy mill" owner—told The Washington Post in 2016, "This is a customer-driven industry. If we weren't satisfying the customer, we'd starve to death. I've never seen prices like the ones we're seeing now, in my whole career."
That breeder, though, is also among leading industry voices who say they understand that public perception of what's acceptable and what's not in a breeding kennel has changed. Regardless of what the laws are, they say, kennels must change along with the public's wishes if the commercial breeding industry is going to survive. The question is how, exactly, to move from the past to the future, at a time when demands for change have reached a fever pitch.
"The Animal Welfare Act, that was gospel. It meant you were taking care of dogs," says Bob Vetere, former head of the American Pet Products Association and now chairman of the Pet Leadership Council. "That was, what, 40 years ago? Things have evolved. People understand much more since then—and back then, there were maybe 20 million dogs in the country. Now, there's 90 million. It's that dramatic. People love their dogs, and everybody is going to get one."
Vetere became an early supporter of Croney's research, which, unbelievably, became the first ever to focus on what it actually means to run a good commercial breeding kennel. At the start of her research, Croney found that the scientific literature underpinning many existing laws and opinions was not just lacking, but outright nonexistent.
"We kept finding it over and over," she says of the literature gaps, citing common but uninformed beliefs about appropriate kennel size as just one example. "I can't find any research about how much space they're supposed to have. People said, 'Yeah, we had a meeting and a bunch of people made some recommendations.'"
She started filling in the research gaps with her team at Purdue, building relationships with dog breeders until she had more than 100 kennels letting her methodically figure out what was actually working for the dogs.
"The measurable successes in animal welfare over the past 50 years began from a foundation in science."
Creating Standards from Scratch
Other industry players soon took notice. One was Ed Sayres, who had served as CEO of the ASPCA for nearly a decade before turning his attention to lobbying efforts regarding the "puppy mill" issue. He recognized that what Croney was doing for commercial breeding mirrored the early work researchers started a half-century ago in the effort that led to better shelters all across America today.
"The measurable successes in animal welfare over the past 50 years began from a foundation in science," Sayres says. "Whether it was the transition to more humane euthanasia methods or how to manage dog and cat overpopulation, we found success from rigorous examination of facts and emerging science."
Sayres, Vetere, and others began pushing for the industry to support Croney's work, moving the goalposts beyond Indiana to the entire United States.
"If you don't have commercial breeding, you have people importing dogs from overseas with no restrictions, or farming in their backyards to make money," Vetere says. "You need commercial breeders with standards—and that's what Candace is trying to create, those standards."
Croney ended up with a $900,000 grant from three industry organizations: the World Pet Association, Pet Food Institute, and the Pet Industry Joint Advisory Council. With their support, she created a nationwide program called Canine Care Certified, like a Good Housekeeping Seal of Approval for a kennel. The program focuses on outcome-based standards, meaning she looks at what the dogs tell her about how well they are doing through their health and behavior. For the most part, beyond baseline requirements, the program lets a breeder achieve those goals in whatever ways work for the dogs.
The approach is different from many legislative efforts, with laws stating a cage must be made three feet larger to be considered humane. Instead, Croney walks through kennels with breeders and points out, for instance, which puppies in a litter seem to be shy or fearful, and then teaches the breeders how to give those puppies better socialization. She helps the breeders find ways to introduce dogs to strangers and objects like umbrellas that may not be part of regular kennel life, but will need to become familiar when the breeding dog retires and gets adopted into a home as a pet. She helps breeders understand that dogs need mental as well as physical stimulation, whether it comes from playing with balls and toys or running up and down slides.
The breeders can't learn fast enough, Croney says, and she remains stunned at how they constantly ask for more information—an attitude that made her stop using the term "puppy mill" to describe them at all.
"Now, full disclosure: Given that all of these kennels had volunteered, the odds were that we were seeing a skewed population, and that it skewed positive," she says. "But if you read what was in the media at the time, we shouldn't have been able to find any. We're told that all these kennels are terrible. Clearly, it was possible to get a positive outcome."
To Buy or Not to Buy?
Today, she says, she's shocked at how quickly some of the kennels have improved. Facilities that appalled her at first sight now have dogs greeting people with wagging tails.
"Not only would I get a dog from them, but would I put my dog there in that kennel temporarily? Yeah, I would."
"The most horrifying thing I learned was that some of these people weren't doing what I'd like to see, not because they didn't care or only wanted money, but because nobody had ever told them," she says. "As it turned out, they didn't know any different, and no one would help them."
For Americans who want to know whether it's OK to get a commercially bred puppy, Croney says she thinks about her own dogs. When she started working with the breeders, there were plenty of kennels that, she says, she would not have wanted to patronize. But now she's changing her mind about more and more of them.
"I'm just speaking as somebody who loves dogs and wants to make sure I'm not subsidizing anything inhumane or cruel," she says. "Not only would I get a dog from them, but would I put my dog there in that kennel temporarily? Yeah, I would."
She says the most important thing is for consumers to find out how a pup was raised, and how the pup's parents were raised. As with most industries, commercial breeders run the gamut, from barely legal to above and beyond.
Not everyone agrees with Croney's take on the situation, or with her approach to improving commercial breeding kennels. In its publication "Puppy Mills and the Animal Welfare Act," the Humane Society of the United States writes that while Croney's Canine Care Certified program supports "common areas of agreement" with animal-welfare lobbyists, her work has been funded by the pet industry—suggesting that it's impure—and a voluntary program is not enough to incentivize breeders to improve.
New laws, the Humane Society states, must be enacted to impose change: "Many commercial dog breeding operators will not raise their standards voluntarily, and even if they were to agree to do so it is not clear whether there would be any independent mechanism for enforcement or transparency for the public's sake. ... The logical conclusion is that improved standards must be codified."
Croney says that type of attitude has long created resentment between breeders and animal-welfare activists, as opposed to actual kennel improvements. Both sides have a point; for years, there have been examples of bottom-of-the-barrel kennels that changed their ways or shut down only after regulators smacked them with violations, or after lawmakers raised operating standards in ways that required improvements for the kennels to remain legally in business.
At the same time, though, powerful organizations including the Humane Society—which had revenue of more than $165 million in 2018 alone—have routinely pushed for bans on stores that sell commercially bred puppies, and have decried "puppy mills" in marketing and fund-raising literature, without offering financial grants or educational programs to kennels that are willing to improve.
Croney believes that the reflexive demonization of all commercial breeders is a mistake. Change is more effective, she says, when breeders "want to do better, want to learn, want to grow, and you treat them as advocates and allies in doing something good for animal welfare, as opposed to treating them like they're your enemies."
"If you're watching undercover videos about people treating animals in bad ways, I'm telling you, change is happening."
She adds that anyone who says all commercial breeders are "puppy mills" needs to take a look at the kennels she's seen and the changes her work has brought—and is continuing to bring.
"The ones we work with are working really, really hard to improve and open their doors so that if somebody wants to get a dog from them, they can be assured that those dogs were treated with a level of care and compassion that wasn't there five or 10 years ago, but that is there now and will be better in a year and will be much better in five years," she says. "If you're watching undercover videos about people treating animals in bad ways, I'm telling you, change is happening. It is so much better than people realize, and it continues to get even better yet."
This fall, Robert Reinhart of Boston University published a study finding that electrical stimulation can boost memory - and Reinhart was surprised to discover the effects lasted a full month.
Scientists believe brain circuits tend to uncouple as we age. Since brain neurons communicate by exchanging electrical impulses with each other, the breakdown of these links and associations could be what causes the “senior moment”—when you can’t remember the name of the movie you just watched.
In 2019, Boston University researchers led by Robert Reinhart, director of the Cognitive and Clinical Neuroscience Laboratory, showed that memory loss in healthy older adults is likely caused by these disconnected brain networks. When Reinhart and his team stimulated two key areas of the brain with mild electrical current, they were able to bring the brains of older adult subjects back into sync — enough so that their ability to remember small differences between two images matched that of much younger subjects for at least 50 minutes after the testing stopped.
Reinhart wowed the neuroscience community once again this fall. His newer study in Nature Neuroscience presented 150 healthy participants, ages 65 to 88, who were able to recall more words on a given list after 20 minutes of low-intensity electrical stimulation sessions over four consecutive days. This amounted to a 50 to 65 percent boost in their recall.
Even Reinhart was surprised to discover the enhanced performance of his subjects lasted a full month when they were tested again later. Those who benefited most were the participants who were the most forgetful at the start.
An older person participates in Robert Reinhart's research on brain stimulation.
Robert Reinhart
Reinhart’s subjects only suffered normal age-related memory deficits, but NIBS has great potential to help people with cognitive impairment and dementia, too, says Krista Lanctôt, the Bernick Chair of Geriatric Psychopharmacology at Sunnybrook Health Sciences Center in Toronto. Plus, “it is remarkably safe,” she says.
Lanctôt was the senior author on a meta-analysis of brain stimulation studies published last year on people with mild cognitive impairment or later stages of Alzheimer’s disease. The review concluded that magnetic stimulation to the brain significantly improved the research participants’ neuropsychiatric symptoms, such as apathy and depression. The stimulation also enhanced global cognition, which includes memory, attention, executive function and more.
This is the frontier of neuroscience.
The two main forms of NIBS – and many questions surrounding them
There are two types of NIBS. They differ based on whether electrical or magnetic stimulation is used to create the electric field, the type of device that delivers the electrical current and the strength of the current.
Transcranial Current Brain Stimulation (tES) is an umbrella term for a group of techniques using low-wattage electrical currents to manipulate activity in the brain. The current is delivered to the scalp or forehead via electrodes attached to a nylon elastic cap or rubber headband.
Variations include how the current is delivered—in an alternating pattern or in a constant, direct mode, for instance. Tweaking frequency, potency or target brain area can produce different effects as well. Reinhart’s 2022 study demonstrated that low or high frequencies and alternating currents were uniquely tied to either short-term or long-term memory improvements.
Sessions may be 20 minutes per day over the course of several days or two weeks. “[The subject] may feel a tingling, warming, poking or itching sensation,” says Reinhart, which typically goes away within a minute.
The other main approach to NIBS is Transcranial Magnetic Simulation (TMS). It involves the use of an electromagnetic coil that is held or placed against the forehead or scalp to activate nerve cells in the brain through short pulses. The stimulation is stronger than tES but similar to a magnetic resonance imaging (MRI) scan.
The subject may feel a slight knocking or tapping on the head during a 20-to-60-minute session. Scalp discomfort and headaches are reported by some; in very rare cases, a seizure can occur.
No head-to-head trials have been conducted yet to evaluate the differences and effectiveness between electrical and magnetic current stimulation, notes Lanctôt, who is also a professor of psychiatry and pharmacology at the University of Toronto. Although TMS was approved by the FDA in 2008 to treat major depression, both techniques are considered experimental for the purpose of cognitive enhancement.
“One attractive feature of tES is that it’s inexpensive—one-fifth the price of magnetic stimulation,” Reinhart notes.
Don’t confuse either of these procedures with the horrors of electroconvulsive therapy (ECT) in the 1950s and ‘60s. ECT is a more powerful, riskier procedure used only as a last resort in treating severe mental illness today.
Clinical studies on NIBS remain scarce. Standardized parameters and measures for testing have not been developed. The high heterogeneity among the many existing small NIBS studies makes it difficult to draw general conclusions. Few of the studies have been replicated and inconsistencies abound.
Scientists are still lacking so much fundamental knowledge about the brain and how it works, says Reinhart. “We don’t know how information is represented in the brain or how it’s carried forward in time. It’s more complex than physics.”
Lanctôt’s meta-analysis showed improvements in global cognition from delivering the magnetic form of the stimulation to people with Alzheimer’s, and this finding was replicated inan analysis in the Journal of Prevention of Alzheimer’s Disease this fall. Neither meta-analysis found clear evidence that applying the electrical currents, was helpful for Alzheimer’s subjects, but Lanctôt suggests this might be merely because the sample size for tES was smaller compared to the groups that received TMS.
At the same time, London neuroscientist Marco Sandrini, senior lecturer in psychology at the University of Roehampton, critically reviewed a series of studies on the effects of tES on episodic memory. Often declining with age, episodic memory relates to recalling a person’s own experiences from the past. Sandrini’s review concluded that delivering tES to the prefrontal or temporoparietal cortices of the brain might enhance episodic memory in older adults with Alzheimer’s disease and amnesiac mild cognitive impairment (the predementia phase of Alzheimer’s when people start to have symptoms).
Researchers readily tick off studies needed to explore, clarify and validate existing NIBS data. What is the optimal stimulus session frequency, spacing and duration? How intense should the stimulus be and where should it be targeted for what effect? How might genetics or degree of brain impairment affect responsiveness? Would adjunct medication or cognitive training boost positive results? Could administering the stimulus while someone sleeps expedite memory consolidation?
Using MRI or another brain scan along with computational modeling of the current flow, a clinician could create a treatment that is customized to each person’s brain.
While Sandrini’s review reported improvements induced by tES in the recall or recognition of words and images, there is no evidence it will translate into improvements in daily activities. This is another question that will require more research and testing, Sandrini notes.
Scientists are still lacking so much fundamental knowledge about the brain and how it works, says Reinhart. “We don’t know how information is represented in the brain or how it’s carried forward in time. It’s more complex than physics.”
Where the science is headed
Learning how to apply precision medicine to NIBS is the next focus in advancing this technology, says Shankar Tumati, a post-doctoral fellow working with Lanctôt.
There is great variability in each person’s brain anatomy—the thickness of the skull, the brain’s unique folds, the amount of cerebrospinal fluid. All of these structural differences impact how electrical or magnetic stimulation is distributed in the brain and ultimately the effects.
Using MRI or another brain scan along with computational modeling of the current flow, a clinician could create a treatment that is customized to each person’s brain, from where to put the electrodes to determining the exact dose and duration of stimulation needed to achieve lasting results, Sandrini says.
Above all, most neuroscientists say that largescale research studies over long periods of time are necessary to confirm the safety and durability of this therapy for the purpose of boosting memory. Short of that, there can be no FDA approval or medical regulation for this clinical use.
Lanctôt urges people to seek out clinical NIBS trials in their area if they want to see the science advance. “That is how we’ll find the answers,” she says, predicting it will be 5 to 10 years to develop each additional clinical application of NIBS. Ultimately, she predicts that reigning in Alzheimer’s disease and mild cognitive impairment will require a multi-pronged approach that includes lifestyle and medications, too.
Sandrini believes that scientific efforts should focus on preventing or delaying Alzheimer’s. “We need to start intervention earlier—as soon as people start to complain about forgetting things,” he says. “Changes in the brain start 10 years before [there is a problem]. Once Alzheimer’s develops, it is too late.”