Actress Kelly Rutherford, with her dog, attends the Zadig & Voltaire September 2017 fashion show during New York Fashion Week at Cedar Lake in Manhattan on Sept. 11, 2017.
Nina Agdal and her puggle Daisy attend the Zadig & Voltaire September 2017 fashion show during New York Fashion Week at Cedar Lake in Manhattan on Sept. 11, 2017.
"Watch What Happens Live" host Andy Cohen posted a photo of him and his dog in Sag Harbor during their "last adventure of the summer" on Monday, Sept. 4, 2017.
Bruno Mars poses for a photo on Monday, July 3, 2017, with his dog. He captioned it "MY BOY".
Brooke Shields frequently posts photos of her dog, Pepper, to Instagram. The actress uploaded this photo of the duo cuddling in bed on Saturday, June 10, 2017.
Kim Kardashian posted this picture of sister puppies that she got for her daughter, North, and niece, Penelope. Penelope named her dog Honey.
Ellie Goulding posted this photo on her Instagram account with her cat Lennon.
Liam Hemsworth and his dog posse pose for a picture on Friday, Oct. 28, 2016. ". . . We are supporting young Aussies living with cancer by wearing @canteen_aus bandannas. #bandannaday is today in Australia so get behind this great cause and shop for your favorite style at www.supportbandannaday.com And on a side note if you look closely three out of four of these dogs have their upper lips caught #perfectsnap 😛 #bandannaday @canteen_aus," he captioned the photo.
Bethenny Frankel snapped a photo of her and Fido, and captioned it, "Baby's first selfie @biggysmallz."
"How to Get Away With Murder" star Jack Falahee poses with his dogs, Oct. 27, 2016.
Julianne Hough shares some quality time with her two pups.
For National Pet Day, actress Bella Thorne posted this picture of her "grumpy" cat, with the caption: "That's my grumpy Gil #nationalpetday @lolanlouis #mommyandme #homestuck #tot #rainydays"
Ariana Grande posted this photo to her Instagram account with the caption "woman's best friend."
Actor Ryan Reynolds posted this snap of his dog Billie, with Off Leash K9 dog trainer Nick White.
Oprah poses with her pups while on a hike.
Kelly Osbourne poses poolside with her kitty. "Just hanging by the pool with my 😻 #Mo 🌊💦💜," she captioned the shot.
Amanda Seyfried posted this Instagram photo with her best friend Finn, with the caption "I voted. He tried."
Andy Cohen and his rescue dog Wacha take a sweet snap posted on social media.
First lady Michelle Obama and YouTube star Tyler Oakley spend time with the Obamas' dogs, Sunny and Bo, in the White House.
Dwayne Johnson enjoys a beach stroll with his French bulldog Hobbs.
Debby Ryan shares many photos of her cats on Instagram. Here is Velma.
Eva Mendes poses with Ryan Gosling's beloved dog George, for Walgreens Red Nose Day.
Ryan Lochte enjoyed some R&R with his pup. "Carter and I watching the #nbaplayoffs," he captioned this photo.
Actress Olivia Munn can't get enough of her puppy Frank. She posted this photo on Instagram with the caption, "Meet Frank Rodgers. Frankie for short. Mr. Frank for business meetings."
Kim Kardashian posted this photo to Twitter of her cat, Mercy, in 2012.
Jessica Biel posted a photo on Instagram of her spending time with her dog with the caption "Tuesdays with Tina."
Sharon Osbourne posted this photo on social media with the caption "Me with my darlings" on National Pet Day.
Country singer Miranda Lambert posted this silly snap on her Instagram account with rescue pup Rosie.
Lauren Conrad missed her pup while away on a trip to Guatemala. Conrad posted an Instagram with the caption, "Had an amazing time in Guatemala, but I am pretty happy to come home to this little guy."
Actress Emmy Rossum is a huge supporter of adopting your next pet from your local shelter. Rossum posted this photo on Instagram with her four-legged companion Pepper.
Ceelo Green brings his pooch along for an appearance on "Jimmy Kimmel Live."
Katy Perry takes her dog Butters on a shopping trip and posted the adventure on Instagram.
Olivia Munn posted this photo to her Instagram account of boyfriend Aaron Rodgers with the caption "and a million times over, my heart melts..."
Martha Stewart posted this photo with the caption "the ultimate squad."
Singer Andy Grammer posted the perfect "Friday Vibes" photo on Instagram while relaxing with his furry friend.
Reese Witherspoon cozies up to her French bulldog Pepper.
"Real Housewives of Beverly Hills" star Lisa Vanderpump never travels without her sidekick Giggy, the Pomeranian pup.
Nicole Richie's dog Iro shows his patriotism with a red, white and blue bandana.
Alex Pettyfer posted this adorable photo on Instagram with the caption "pure love!"
"Follow my dog @olivebeckham23," Brooklyn Beckham posted to Instagram on Dec. 14, 2015.
Dog lovers John Legend and Chrissy Teigen sit back and relax with their pooch.
Lucy Hale posted this photo of her furry companion on Instagram with the caption "Thank you Lord for this little guy -- makes my life so much sweeter."
Actress Ashley Tisdale takes a photo with her beloved puppy Maui.
Brody Jenner posted this snap on his Instagram account cruising around with his pup Shoey.
Britney Spears and her "baby Daisy" pose for an Instagram selfie on Wednesday, Sept. 7, 2016.
Mandy Moore posted this throwback photo on Instagram on Sept. 18, 2014. "Waaaay back in '09 when we brought the 'big oranges' home," she wrote.
Demi Lovato captured a cuddle session with her dog, Batman, and posted it on Instagram.
"The Big Bang Theory" star Kaley Cuoco is a dog lover and an equestrian, as evidenced by her Instagram page full of photos of the actress snuggled up with her pups, Ruby, pictured, and Norman, and showing horses some love.
Kylie Jenner posted to Instagram this sweet shot with one of her dogs, and captioned it "Pug Lyfe."
Maria Menounos posted this photo on Instagram of her showing her pup Benji some love.
Singer Ed Sheeran posted this photo of himself with his kitten, Graham, with the caption "Daddy's home."
Ian Somerhalder shared this photo of himself with his dog Neech to Instagram on Jan. 3, 2015.
Paris Hilton poses with her two Pomeranian pups, Price Hilton, right, and Princess Paris Jr., at the taping of the 2015 World Dog Awards at the Barker Hanger in Santa Monica, California, on Jan. 10, 2015.
Ashley Benson celebrates New Year's Eve with her pups. Benson posted this photo to Instagram on Dec. 31, 2014.
Miley Cyrus posted this photo of herself lounging with her dog Emu on Nov. 7, 2014, with the caption "best friends."
Miranda Lambert with an adoptable pup. She posted this photo to Instagram on Nov. 3, 2014.
Taylor Swift posted this photo of herself and Olivia Benson (her kitten) on June 18, 2014.
Hugh Jackman posted this photo of himself with his dog on Oct. 27, 2014.
Emmy Rossum enjoyed a lazy Sunday afternoon with her dog. She posted this photo to Instagram on Oct. 5, 2014.
Joan Rivers, who died in September 2014, uploaded this photo to Twitter a month earlier, with the caption "With my darling Teegan at @qvc this past Monday."
Little Mix's Perrie Edwards shared this photo of her cat sleeping.
"Had an amazing time in Guatemala, but I am pretty happy to come home to this little guy," Lauren Conrad wrote on March 24, 2014.
Catherine, Duchess of Cambridge (the former Kate Middleton), and Prince William, Duke of Cambridge, pose for a photograph with their son, Prince George Alexander Louis of Cambridge, along with Lupo, the couple's cocker spaniel, and Tilly the retriever, a Middleton family pet, in the garden of the Middleton family home in Bucklebury, Berkshire, in August 2013.
Jessica Biel posted this photo of herself holding her dog on July 30, 2013. She added the hashtag "TuesdayswithTina."
Hilary Duff lounges with her dog Jak on July 18, 2013.
Amanda Seyfried posted this photo of herself cuddling with her dog on May 29, 2013.
Martha Stewart with her dog Paw Paw at her home in Bedford, N.Y. The 60-pound chow's full name was Kublai Khan Paw Paw Chow Chow Chow.
Lea Michele posed with her cat Sheila, whom she found while filming "Glee," in 2015's People magazine's Most Beautiful Woman issue.
Animal lover Betty White poses with Uggie the dog, from the film "The Artist," as she arrives for her Friars Club Roast in New York on Wednesday, May 16, 2012.
Hilary Swank with her two adopted dogs Karoo, left, and Rumi in Malibu, Calif., on Thursday, Jan. 14, 2010.
President Barack Obama and his daughters, Malia and Sasha, on the South Lawn of the White House with Bo, the first family's Portuguese water dog, on April 14, 2009.
"Glee" actor Kevin McHale took his cat James for a spin and captured the moment for Instagram.
Colombian singer Shakira and Antonio de la Rua pet their dog outside their farmhouse, "La Colorada," in Jose Ignacio, Maldonado, Uruguay, on Dec. 20, 2009.
Julianne Hough and her dog Lexi attend the Netflix "Wizard of Oz" outdoor concert and screening in Central Park in Manhattan on Tuesday, Sept. 29, 2009.
Paris Hilton holds her dog Tinkerbell during a taping of "The Tonight Show with Jay Leno" on Monday, Sept. 6, 2004, in Burbank, Calif.
Ian Somerhalder's a proud papa. "Somer Being a Dad... Morning vet visit with Moke before heading to my 1st Day of work for SEASON 6 of The Vampire Diaries!..." the actor captioned this photo, seen on Instagram.
Sophia Bush sits in the doorway of her trailer with her dog between takes for the WB series "One Tree Hill" on Nov. 18, 2003, on the Screen Gems lot in Wilmington, N.C.
Fran Dresher is photographed with her dog, Chester, at the Four Seasons Hotel on Jan. 21, 1997.