Humans aren’t the only ones struggling to get their summer bodies back after gaining the notorious “Quarantine 15” during lockdown.

According to a survey for Banfield Pet Hospital conducted by Wakefield Research, about 33 percent of pets have beefed up since the coronavirus hit in March.

And it’s not just because dog runs have been closed.

“People are home all day with their pet on their laps like, ‘Oh, you’re so cute. You deserve a treat,’ ” says Dr. Ann Hohenhaus, a veterinarian at New York City’s Animal Medical Center. “These fun food treats that they love are in the rank of burritos and ice cream for us humans — and can pack on the pounds really quickly.”

Now, some cat and dog owners are putting their four-legged pals on strict diet plans.

Hohenhaus advises owners hoping to help pets slim down make sure that only 10 percent of the animals’ daily caloric intake comes from treats. Carving out time for daily exercise is important.

“People with little dogs and cats are very tempted just to pick them up and carry them around because they’re cuddly, but they need to walk and they need to do stairs,” says Hohenhaus. “[Otherwise,] they lose that muscle strength.”

Just be sure to consult a veterinarian before changing your pet’s diet or exercise regimen, advises Hohenhaus.

Here, three people detail their pets’ weight-loss journeys to The Post.

Holly, 2-year-old Australian shepherd

Lost: 10 pounds in one month

Julia Bozzone was two months into quarantine at her parents’ home in Pittsburgh when she noticed her dog, Holly, looked different.

“I was walking with her and thought, ‘Whoa, your stomach is going out way past your legs and is way bigger than normal,’ ” Bozzone, 24, says. “She really put it on.”

The corporate sales representative from Chicago weighed the paunchy pooch, only to find that she’d gained nearly 15 pounds. “At first I thought, ‘This is funny’ — because it was honestly pretty cute,” Bozzone says. “But then as I started to be here two, then three months, I was like, ‘OK, wait, we’ve got to get a hold on this.”

She blames the newfound bulk on her dad spoiling Holly with raw meat twice a day — and filling up the dog bowl to the brim.

“She loves it, but it must definitely be higher in fat [than what I usually feed her] because she started gaining weight immediately,” Bozzone says. “It’s sort of like when you’re younger and you go to your grandparents’ house and they feed you a bunch of cookies.”

Determined to whip her pup back into shape, Bozzone switched Holly to a dry food diet and bought her a life vest for swimming laps in the family’s pool.

“She loves it and it really tires her out more than anything,” says the dog mom.

After a month of determination, Holly’s gone from 55 to 45 pounds. The goal is to get her to 40.

“She’s still a little thicker than she was before, but she’s on the right track,” says Bozzone.

Finn Diesel, 10-year-old cat

Lost: 2 pounds in two months

Finn Diesel has struggled with his weight ever since his owner, Beth Moses, rescued him from the Humane Society eight years ago.

“He gets very anxious and stressed out if he sees the bottom of the food bowl,” says Moses, 30.

When quarantine hit, she and her boyfriend started spending most of their time at home rather than at work.

“I noticed just how sluggish he was and, at first, thought he was just a typical cat — being annoyed we’re home all the time and just over it,” says the St. Louis resident. “But then we were like, ‘Maybe this is more than just him being a cat. Maybe he’s unhealthy.’”

So she plopped Finn Diesel on the scale in mid-April and was surprised to find he’d reached a whopping 24 pounds. (A healthy weight for a cat of his size and age is about 10 pounds, according to WebMD.)

Since Moses already knew Finn had a tough time with food, she decided to focus on fitness instead.

“We try to engage him more and do some laser pointer time at least once a day,” she says. “And since we’re home to play and distract him, he ends up eating less.”

But the real game changer was a bird feeder that they placed outside their window.

“He has to jump up on a cedar chest that’s probably about 2 1/2 feet tall in order to get to the window,” says Moses, a research coordinator for cancer trials. “He never ever jumped on it before, so I think that movement helped get him get lighter and more muscular.”

The fat feline is now on his way to reaching the chiseled ranks of his namesake — action star Vin Diesel, of course — and has lost 2 pounds.

Brody, 4-year-old Labrador retriever

Lost: 6 pounds in three months

Donna Hanlon first started her 4-year-old black Lab, Brody, on a diet last fall at the orders of her veterinarian. But when the lockdown began, and their go-to spot for walks — Gateway National Park Sandy Hook — shut down, he started putting on weight again.

“We really hit that stagnant time where he couldn’t lose weight because we weren’t exercising like [before],” says Hanlon, who lives in Monmouth County on the Jersey Shore and is a watercolor painter. “Brody is afraid of other dogs so it became really hard to find a place to take him where he felt comfortable and safe. So we walked less and less.”

After a March visit to the vet — who “was a little upset that he had gained weight” and was up 8 pounds, from 96 to 104 pounds — Hanlon had to find other ways to help Brody melt fat.

Limiting his treat intake to only 70 calories a day, she also had to have a tough talk with a generous neighbor.

“He gives Brody Milk-Bones that he throws over the fence, [so] I had to say, ‘Please don’t give him any more,’ ” Hanlon says.

Now, the dog enjoys frozen yogurt cubes in place of fattier treats, and plays outdoor games like fetch with a ball. And he’s down to 98 pounds.

“He’s like a puppy again — tired and satisfied at the end of the day,” Hanlon says. “I’m so proud of him.”

Source: New York Post