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Fenrir, the world’s tallest living cat, supports animal shelters and HIV patients

The F2 Savannah cat stands 18.83 inches tall and is the “world’s tallest living domestic cat," according to Guinness World Records.
Fenrir, an F2 Savannah cat who lives in Michigan, stands 18.83 inches tall and set a mark recognized by the Guinness World Records of “world’s tallest living domestic cat.”
Fenrir, an F2 Savannah cat who lives in Michigan, stands 18.83 inches tall and set a mark recognized by the Guinness World Records of “world’s tallest living domestic cat.”Courtesy Dr. Will Powers

Dr. Will Powers was inside the surgical suite at his medical practice when his cat Fenrir opened the door and burst into the room, looking for attention.

“I had to stop the procedure and get him out of the room,” Powers, 37, told TODAY. “After that we put up the extra lock on the door because otherwise, Fenrir can open it.”

While having a cat tall enough to open doors is an unusual problem, Fenrir holds the Guinness World Records title of “world’s tallest living domestic cat.”

Dr. Will Powers holds Fenrir, an F2 Savannah cat, the world’s tallest living cat according to Guinness World Records.
Dr. Will Powers holds Fenrir, an F2 Savannah cat, the world’s tallest living cat according to Guinness World Records.Courtesy Dr. Will Powers

The 35-pound F2 Savannah cat — a breed recognized by The International Cat Association — is a cross between a domestic cat and an African serval.

Because Powers made sure many people held him as a kitten and frequently touched his paws, Fenrir developed into a friendly cat who loves meeting new friends. He thrives in his work as a therapy cat at Powers Family Medicine, his owner's medical practice, offering stress relief to patients with HIV.

Powers, a physician and HIV specialist, recently headed to a room at his office to break the news to a patient that they tested positive for HIV. Fenrir followed close behind.  

“I open the door, and he immediately runs in and pops up on the exam table. The patient’s like, “The big boy!’ They’re all happy, petting him,” he said. 

As Powers shared the diagnosis, the patient kept petting Fenrir. Powers explained that he is a specialist and can treat HIV with various approaches. He assured the patient they wouldn’t get sick.

The patient calmly responded, “OK, that sounds good.”

“I’ve had people break down and sob and feel like their life is over, but when Fenrir’s there, it’s just a distraction from that situation for a moment,” Powers said. “It’s calming.”

Powers designed his medical practice to incorporate his passions, like video games, geology and therapy cats.
Powers designed his medical practice to incorporate his passions, like video games, geology and therapy cats.Courtesy Dr. Will Powers

Some people even request a visit from Fenrir before injections or other procedures. But the feline doesn’t let his popularity go to his head.

“He’s a big, lovable doofus,” Powers said. “He’s very, very friendly and silly. He loves to play. He jumps into stuff he’s way too big for because he just doesn’t realize how giant he became.”

Fenrir loves eating and can reach countertops, so Powers has to be careful to keep food under lock and key unless it's time for a treat.
Fenrir loves eating and can reach countertops, so Powers has to be careful to keep food under lock and key unless it's time for a treat.Courtesy Dr. Will Powers

At home, Fenrir is one of six pet cats. Remarkably, he is the doctor’s fourth cat to set a mark recognized by the Guinness World Records. His Maine coon, Altair, currently holds the record for “longest tail on a domestic cat living.”

Altair’s tail measures 16.07 inches – a Guinness World Record.
Altair’s tail measures 16.07 inches – a Guinness World Record.Courtesy Dr. Will Powers

His late cat Cygnus holds the Guinness World Record for the longest tail on a domestic cat ever (17.58 inches), and another of his late cats, Arcturus, reigns as the tallest domestic cat ever (19.05 inches).

“I didn’t mean to make Guinness World Record cats, I just meant for my cats to be healthy,” he said. “And then it just happened.”

Powers credits the health of his cats to their breeder, Stacee Dallas of Starfell Savannahs in Traverse City, Michigan — who bred both Arcturus and Fenrir — and to a special diet he concocted.

All six of his cats eat a blend of raw chicken, slow-cooked meats (for easy digestion), ground-up pig bones, krill oil, feline multivitamins and other supplements.

“So it’s kind of genetics and then the combination of my diet and me being a doctor and making sure they had everything they needed to be as healthy as possible,” he said. “I put a tremendous amount of time and effort into them.”

Powers strongly believes his cats get along so well because he raised them to have positive associations with one another. In cold Michigan winters, he provides a large, heated cat bed that they can share together.
Powers strongly believes his cats get along so well because he raised them to have positive associations with one another. In cold Michigan winters, he provides a large, heated cat bed that they can share together.Courtesy Dr. Will Powers

Powers noted that Savannah cats aren’t a good fit for inexperienced pet owners or those who can’t commit to providing the cats with early socialization and ongoing enrichment activities (a consideration for any breed of cat).

His home has a large outdoor enclosure for his pets, and he spends time playing with each cat. Still, they’re large and can be destructive even with so much attention and care.

“Fenrir chews on my computer chair. He’s ripped the leather off of it. He’s destroyed it basically,” he said. “But I don’t care.”

Powers encourages cat lovers to provide their pets with high vantage points, as well as areas where they can hide, to feel safe.
Powers encourages cat lovers to provide their pets with high vantage points, as well as areas where they can hide, to feel safe.Courtesy Dr. Will Powers

He can be a tad rankled by hate mail he gets on social media from people imploring him to “Adopt — don’t shop.” In addition to adopting rescue cats in the past, Powers is the former president of Ferndale Cat Shelter in metro Detroit and volunteers in his spare time doing trap-neuter-return missions in the rural area around his home in Farmington Hills, Michigan.

Perhaps most impactfully, he uses the notoriety his cats gain from holding Guinness World Records to raise money for animal shelters. Before Arcturus and Cygnus perished in a tragic 2017 house fire that nearly claimed Powers’ life as well, they raised over $40,000 for Ferndale Cat Shelter through photo-ops, meet-and-greets and other charitable appearances.

Powers, who describes himself as a “high-functioning autistic,” is rebuilding his life after the terrible fire nearly five years ago — and his six cats are a huge part of the healing process.

Powers snuggles with Fenrir.
Powers snuggles with Fenrir. Courtesy Dr. Will Powers

He's excited for the chance to help shelters with Fenrir’s newfound fame as a Guinness World Record holder and welcomes requests from any animal shelter in or around Detroit for Fenrir to make fundraising appearances. They already have an event planned to benefit a shelter in Monroe, Michigan.

“I’m really looking forward to doing charity work with him,” he said. “He’s going to do so much good.”