It had been a year since Henry's last haircut, and Michelle Holbrook didn't realize that her 7-pound, goofy toy poodle was now almost 9 pounds. His cute, shaggy look not only obscured his weight, but also made it harder for the Holbrooks to resist his begging.

"He's a little rascal," said Holbrook, a medical researcher in Chicago. "He'll hear me when I open the cheese drawer in the fridge, and he comes running."

Henry, 7, is one of many food-motivated pets who have surprised their owners with their weight gain in the past two years. While veterinarians and pet owners mostly attribute the added pounds to an increasing urge to give into bad habits during the coronavirus pandemic, pet obesity has long been an issue in the United States.

Banfield Pet Hospital, which runs more than 1,000 veterinary clinics nationwide, found that nearly 40% of cats and almost 35% of dogs were diagnosed as overweight in 2020, up from less than 20% a decade ago.

"We're all having pandemic pounds come into play," said Dr. Jennifer Bolser, chief clinic veterinarian for the Humane Society of Boulder Valley in Colorado. For pets, as with humans, bad habits include overeating, too much snacking and not enough physical activity. People find it harder to not overindulge pets while stuck at home with them.

Anthony Osuna, a psychology resident, said he and his partner used to take Pavlov, their petite corgi, to dog-friendly beaches, malls and restaurants in Southern California. But when the pandemic shut things down, Pavlov, 6, lost enthusiasm for outings — even walks.

"I felt like we were disappointing him," Osuna said. "That contributed to a lot of humans' weight gain — the additional snacks and the dessert and the boba and the coffee that you would do just to make yourself feel better in the pandemic. And with him, as well. We would buy him treats, we would give him snacks."

Pavlov's weight crept up to about 28 pounds, from 23, prompting Osuna to reduce his portions and restrict snacks (popcorn is a favorite).

"He didn't look really fat," Osuna said. "But with the additional snacks and the reduced activity, it all added up."

Like dog, like owner

A survey of pet owners by Pumpkin, a pet insurance company, and Fi, which makes smart dog collars, found that more than 50% of dogs that gained weight during the pandemic did so alongside their owners — some even when they were more active. A number of studies have also found that humans and dogs can mirror one another's emotions and stress levels.

Rachel Kiri Walker, who lives in Los Angeles, said she was "very depressed" at the beginning of the pandemic. Then a breakup prompted her boyfriend to move out, separating her dog, Senator Bucky, 5, from his dad.

"Anytime that I would be crying, he would come up and lick my face and be extra cuddly," Walker said. "It's amazing that a creature can be that intuitive."

But she recognized that Bucky was also stressed after he urinated on furniture — deliberately, she said, which he had not done before.

His potential stress, along with extra bone marrow treats and table scraps, probably contributed to his rapid 10-pound gain, Walker said. A fluffy Border collie and golden retriever mix, Bucky is now about 45 pounds.

Symptoms of stress and anxiety in dogs can vary. In a 2018 study published in the Journal of Veterinary Behavior, more than 80% of the owners observed thought their dogs displayed signs of emotional eating, or "stress eating" behavior when they were "unhappy."

As owners return to pre-pandemic routines, pets can develop anxiety from other sources.

Henry, Holbrook's toy poodle, has developed separation anxiety when his owners leave for work. Other dogs have had limited socialization during the pandemic, leaving them unable to have healthy interactions with people and animals in what were once typical activities.

Walker said that Bucky, who is otherwise calm, had become possessive about her when other dogs tried to say hello. When she began taking Bucky on hikes to help him shed pounds, she found that he was also excited to encounter and play with other dogs.

But when it comes to weight loss, Bolser said that as with people, it is harder for pets to lose pounds than it is to gain them. More walks cannot always counteract indulgent foods.