Here’s how scientists make exact genetic replicas of our furry best friends—and how identical we can expect them to be.
Meesha Kaufman’s five chihuahuas are a lot alike. Their tails wag, their eyes bulge, and their bark is almost certainly bigger than their bite. They’re all named after superheroes’ secret identities— Bruce Wayne, Tony Stark, Clark Kent, Peter Parker, and Wade Wilson. In other words, they are like any normal pampered chihuahuas. But there are ways to tell the dogs apart.
As the chihuahua’s paw and nibble on each other like two-year-old pups are apt to do, it’s easy to notice that the black spotting on their white-furred bodies varies from dog to dog. Their personalities are also different, Kaufman says, pointing at each dog. “I have an angry one, a funny one, a really sweet one, and one that’s really independent.”
“I THINK PEOPLE WANT OR EXPECT THEM TO BE DIFFERENT. BUT CLONES ARE JUST REGULAR DOGS.”
But these cute, fluffy, energetic long-haired chihuahuas are more alike than different. They are genetically identical; exact DNA matches created from the skin tissue of their slightly older long-haired chihuahua original, Bruce Wayne.
It may be surprising to hear that the cloning of dogs, cats, and horses is taking place here in the United States. Specifically, in a suburban Texas office park by a company called ViaGen Pets and Equine.
“I think people want or expect them to be different,” Kaufman says. “But clones are just regular dogs.”
Since 2015, this cell culture lab inside of a nondescript office building in Cedar Park, Texas (about 20 miles north of Austin) is where hundreds of cloned pets have taken their figurative first steps.
ViaGen Pets and Equine isn’t the only genetics company in the world cloning pets, but it’s the only one in the United States. While there are no official numbers about the number of pets being cloned annually worldwide, ViaGen claims that they may be the most prolific.
“We are cloning a few hundred animals a year,” ViaGen’s president and co- Blake Russell said while sitting in a conference room in January 2020. “We successfully produce healthy, happy cloned animals on a weekly basis.”
In the beginning, they created Dolly.
In February 1997, the Roslin Institute in Edinburgh presented a seemingly normal lamb named Dolly to a shocked world. Created by a team led by embryologist Dr. Ian Wilmut, Dolly was the first mammal to be cloned from an adult cell. There had been prior efforts to clone animals, mainly cattle, pigs, and frogs (which actually worked), but there never had been a successful birth of a cloned mammal.
The process Wilmut used is called Somatic Cell Nuclear Transfer, or SCNT, which remains the industry standard. In this technique, a fertilized egg is extracted from a surrogate of the same species and the egg’s nucleus, which contains nearly all of its chromosomes and DNA, is removed. It is then replaced with another DNA-filled nucleus of a donor adult cell. It’s sort of like wiping a computer hard drive clean and uploading new files. Then, the egg is put back into the surrogate, the replication cycle of the cells are synced up (via chemicals or simply by waiting for it to happen naturally), and the host cell and the donated nucleus fuse together. They will grow and divide, just like a non-cloned fertilized egg, to form an embryo. In the end, the animal should have the DNA of the adult that donated the cell but none of the DNA of the surrogate.
Prior to Dolly, many in the scientific community thought growing cloned cells like this into viable embryos was biologically impossible. But Wilmut and his team shattered this perception. “It’s unbelievable,” a Princeton biology professor told the New York Times at the time. “It means all of science fiction is true. They said it could never be done and now here it is, done before the year 2000.”
Wilmut couched the breakthrough of cloning a mammal as the first step in solving genetic diseases. But he was realistic about where other’s minds may go—the idea of cloning humans, and what impacts that would have on our world, for one. He made it very clear that the cloning process had been incredibly inefficient, time-consuming, and expensive, citing that it took 277 attempts to get one cloned sheep. In an interview on the same day that Dolly was announced, Dr. Wilmut drew a line in the sand. “We are aware that there is potential for misuse… We believe that it is important that society decides how we want to use this technology and makes sure it prohibits what it wants to prohibit,” said Wilmut. “It would be desperately sad if people started using this sort of technology with people.”
While cloning may still be taboo in the human world, the livestock industry has embraced it in the two decades since Dolly for practical reasons. For example, if a dairy cow produces lots of good-tasting milk, what farmer wouldn’t want two of that cow? Or four? Or 40? Companies started cropping up catering to the genetic preservation and cloning of bovines, despite the known inefficiency of it. In 2008, the FDA declared cloned cows safe for dairy production and human consumption. However, to this day, the public is cool with the idea of eating cloned meat and dairy products. Several notable companies and grocery chains, like Whole Foods and Tyson Foods, have, at least in the past, declared that they wouldn’t sell cloned meat, dairy products, or even anything from the naturally-born offspring of clones. Despite the public concern, the FDA has continued to state that there’s no way to distinguish between a cloned animal and a naturally bred one. To this point, the FDA has issued a “voluntary” ban on selling products from cloned animals, meaning they are asking producers not to sell it though there’s no punishment or enforcement if they do. Additionally, no label is required that states if the product is from a cloned animal. What has become clear, though, is that cloning animals for food production is pretty uneconomical, potentially costing upwards of $20,000 per clone. If it was simply going to be eaten, that’s a very expensive steak.
Of course, farmers weren’t the only ones with an interest in cloning animals. In 1998, only 18 months after Dolly, University of Phoenix founder and billionaire John Sperling launched the Missyplicity Project, a multi-million dollar effort to clone his beloved border collie/husky mix Missy. But as it turned out, canines were much more complicated than sheep.
Dr. Mark Westhausin was head of the Missyplicity Project and is now a professor at Texas A&M’s veterinary school. He explains that the reason why dogs are much more difficult to clone than sheep, cattle, or even cats lies with their reproductive cycles—meaning how long their fertilization cycles are. Canine reproductive cycles are long, hard to alter, and random (anywhere from six to 12 months). “Basically, you have to have access to a large number of dogs and wait for each one to show signs that they are coming into heat,” says Westhausin. “Then, even with testing, you can only predict the best time to transfer the [cloned] embryo.” It quickly became clear just how complicated, expensive, and inefficient cloning dogs actually was.
This made Sperling realize that his Missyplicity Project was better suited for a commercial setting, one where private money and multiple clients wanting their own dog clones could push innovation forward. In the end, the Missyplicity Project wasn’t the first to produce a canine clone (Snuppy from South Korea was the first healthy dog clone in 2005), but did end up leading to several successful attempts but never able to offer customers the hoped-for price tag of $20,000.
Meanwhile in 2001, as the Missyplicity Project was ramping down at Texas A&M, its principal investigator, Dr. Duane Kraemer, started cloning cats—an easier proposition than cloning dogs, because cats’ ova mature faster. Using cells from the ovary of a cat named Rainbow, Kraemer and his team utilized the SCNT process and inserted the DNA into another (unnamed) tabby. It worked—a healthy, happy clone that they named CC (or Copy Cat) was born.
This success paved the way for commercial genetic preservation and cloning. After the Missyplicity Project ended, a few of its primary scientists opened companies mostly catering to livestock. Over the next few years, these companies divided, merged, and eventually formed ViaGen, which initially focused on livestock cloning. In 2014, however, after repeated requests from customers, they turned their attention to cloning pets. “Clients kept telling us: ‘Please clone our dog. Please clone our cat,’” Russell says.
Utilizing their livestock experience and the inherited knowledge from previous projects, ViaGen officially became America’s first pet cloning business.
The step-by-step guide to pet cloning
Over the last six-plus years, ViaGen has gradually increased its output of pet clones. Russell says that over the last 15 years with three sets of ownership, more than $100 million has been invested in ViaGen in terms of research and start-up costs. This has allowed them to hone the process and elevate their science for cloning cats, dogs, and horses. And the process so says ViaGen, always ends in a “deliverable” animal, or the client receives a full refund.
The pricing structure is simple: $85,000 for a cloned horse, $50,000 for a dog, and $35,000 for a cat. There are also more affordable options for cryopreserving biopsy samples of your pet ($500), which essentially puts your pet’s genetic info on file in case you decide to clone in the future, or creating cultured cells ($1,600) that are clone-ready. And it’s popular: There are waitlists for all three species, ranging from a few months for a horse to just under six months for a cat.
From extracting DNA to having a living, breathing new best friend, the process often takes 4 to 6 months for dogs and cats.
Here’s how it’s done.
Step 1: GENETIC PRESERVATION
Melanin Rodriguez is ViaGen’s client services manager and her job is to be the first contact for those humans who want to clone their pet. “At least 50% of the time, they are calling us because their pet has just passed away and they weren’t prepared,” Rodriguez says. A pet can be cloned even if it is dead, but the odds shrink the longer it’s been deceased—after five or fewer days, the chances of success drop precipitously. Additionally, the animal should not be frozen (conventional freezing damages DNA), so Rodriguez tells clients to immediately take their pet out of the freezer and put it in the refrigerator.
Step 2: DNA
The animal’s DNA is acquired by a biopsy, often performed by the animal’s doctor. Dr. Joseph Zulty of Essex Middle River Veterinary Center, located just outside of Baltimore, is Meesha Kaufman’s veterinarian. He performed the procedure on her dog, Bruce Wayne. He says it was relatively easy to do, though he did have to sedate the animal. Zulty took several pieces of tissue about two to three millimeters in diameter from the underside of Bruce Wayne’s belly. “The impact on Bruce Wayne was minimal,” says Zultys, “and he was awake within an hour or two, probably not realizing he was soon going to be joined by four lookalikes.”
Then, the doctor sends the samples in a cold storage pack provided by ViaGen. Included is a third-party DNA verification kit that is sent to UC-Davis Genetics Lab for confirming later that the cloned animal is a DNA-exact of the original.
For deceased animals, ViaGen requires larger samples. A partial ear works best due to the lack of fat and extraneous tissue.
Step 3: GROWING THE CELLS
Up to 15 samples a day arrive at ViaGen’s door via FedEx. Most come from dogs, says Sanaz Arenivas, ViaGen’s cell culture manager.
Technicians sterilize the samples and prepare them for cell growth by adding a proprietary nutrient solution. They stick the cells in an incubator set for 99 to 101 degrees Fahrenheit. Then, they watch and wait. “I call it babysitting. We look for cell growth and multiplication,” says Arenivas. “That could be three days or four weeks.” She says the size and condition of the samples can affect the speed of growth, with postmortem tissue often taking the longest.
Once growth and division begin to happen, the cells become viable for insertion into a donor egg. Technicians put the cells in vials for storage in liquid nitrogen tanks. “Due to the perishable nature of the samples, we have to finish [this whole process] on the same day [we receive the samples],” says Arenivas.
Then, they are shipped to ViaGen’s New York lab and kennel where the SCNT process will take place.
Step 4: EGGS
To clone an animal, ViaGen needs oocytes, or unfertilized eggs, to implant the genetic material into. It often gets them by collecting ovaries from spay surgeries performed by sponsoring free spay days.
Next, they ready the egg and perform the SCNT process. Walker says that while the general technique utilized for cloning is basically the same as it was when it was created two decades ago, ViaGen has improved significantly on how the process is implemented.
This is where ViaGen’s cloning process gets purposely a bit hazy to protect their intellectual property. To this point, they were reluctant to reveal exactly how they turn cell-cultured cells into embryos.
Step 5: IVF
At this point, as the culture cells are finished and placed into oocytes, the resulting embryos are then transferred into the surrogate mother. It’s similar to in vitro fertilization (IVF), a procedure first used with humans in the late 1970s where the sperm and egg are fertilized outside of the body in a test tube (hence, the Latin “in vitro” meaning “in glass”). Four decades later, it’s now widely used to assist infertility and it’s estimated that more than 8 million babies have been born using this method.
Timing is a huge factor. In order for the embryos to develop and for the animal to become pregnant, the clone/IVF transfer has to be timed with the animal’s reproductive cycle and while they are in heat. For cats, this can be done artificially with a hormone shot. But for dogs, these shots often don’t work. Meaning, it’s about waiting for the natural cycle to come around which necessitates having more dogs than cats available.
Step 6: SURROGATES
Dog and cat surrogate mothers spend their pregnancies with a breeder in a kennel in the northeastern U.S.
Once the embryo is transferred into the surrogate mother, it plays out almost like a regular pregnancy, with a few key differences.
ViaGen admits that, while they have made their process far more efficient, not every embryo transfer creates a puppy or kitten. There are also times when an embryo transfer results in more puppies than expected. “It’s not perfect science by any stretch,” says Russell, “Like IVF, sometimes they get twins. Or triplets.” In some cases of IVF, a litter produces five—exactly what happened to Meesha Kaufman. In that case, the client can have the additional animals at no additional charge (which is what Kaufman chose to do, deciding to keep four Bruce Wayne clones for herself while giving a friend the fifth). If they can’t take on the additional pets, the ViaGen contract states that the company is responsible for finding forever homes for the others.
Surrogates and embryos do not have to be matching breeds, only be relatively the same size for the safety of the mother. For example, the surrogate mother for Kaufman’s chihuahuas was a beagle. Additionally, sometimes surrogates are pregnant with dogs from multiple clients. Meaning, that beagle could in theory give birth to Kaufman’s chihuahuas and another client’s English foxhound at the same time. “We put embryos [from different clones] into the same surrogate to economize the surrogate,” says Russell. Pregnancies last about the same amount of time for dogs and cats—about 63 days.
Step 7: DELIVERY
ViaGen keeps the cloned puppies and kittens for eight weeks before handing them off to clients. While nobody but employees are allowed to visit the kennel, clients can video chat in to see their new family members for the first time. “Sometimes they’ll send in a t-shirt so their puppy can get used to their smell,” says Russell. When the time comes for the baby animals to go to their new homes, ViaGen employees hand deliver them.
How Identical is My Clone?
Of course, just because a clone is a genetic-exact doesn’t mean it is identical in every way.
Animal clones may be genetically identical and DNA exact, but that doesn’t mean they are necessarily the same as the original. As in the case of Kaufman’s chihuahuas, coat color and spotting can differ.
There’s also a matter of personality and behavior. The science is currently inconclusive on how much of a genetic component there is to personality. ViaGen tells clients not to expect their cloned dog or cat to display the same behaviors as the original.
But employees agree that they’ve seen some behavioral traits being passed down. Over the last 15 years of cloning animals and hearing from clients, Russell and Walker say that they think there’s a large DNA component to behavior. “I think personality and behavior are more genetically controlled than we assumed,” says Walker. From how a dog rolls its tongue just like the original to how a cat taught itself to open doors like its predecessor, they know that this conclusion is based on observations, anecdotal stories, and could be influenced by people wanting to see what they want to see. But they are constantly amazed.
They are not the only ones who believe there’s a significant connection between genes and behavior.
Dr. Gregg Veneklasen has foaled out hundreds of cloned horses for ViaGen at his Texas-based veterinary clinic Timber Creek Veterinary Clinic. “Nobody on earth has seen as many cloned horses as me,” Veneklasen says. There’s little doubt in his mind that genetics play a part in personality, believing in genetic memory which is debated for humans.
Walking around the stables and outdoor enclosures at this rural veterinary hospital, Veneklasen points out horse clone after horse clone and explains what characteristics they’ve inherited from their original—a concept known as genetic memory. One sticks out their tongue sideways the same way. Another has the same gait. A third goes to the bathroom in the manner as its genetic original.
Five of a Kind
The superhero puppies seem to follow one another. If one jumps on the couch, the others follow. If one paw at Kaufman’s knee, the others do the same. Kaufman recognizes that this is likely more about a pack mentality than sharing exact DNA. It’s adorable, but a little strange seeing five of the exact same dog portraying the same mannerisms in unison.
Meesha Kaufman says she has people contact her all the time to ask if she would recommend pet cloning. “Absolutely,” Kaufman says as the dogs run around her feet. In fact, her one criticism is that the procedure was too effective—her last cloning procedure ended up with five dogs when she expected one, which makes her hesitant to try it again while her current dogs are alive. “I don’t want ten [dogs]!”
ViaGen says their goal is to clone more pets cheaper, perhaps for little as $20,000 per animal. And Russell thinks that ViaGen can quadruple the number of pets they clone with the next decade— from about 300 pets a year to more than 1,000.
So far, those numbers are still a small part of the U.S. pet population. But as the process gets less expensive and more effective, it seems inevitable that cloning will only become more mainstream. So keep an eye out—clones might be coming soon to a dog park near you.