Falling in love may be the risk one takes as a foster care volunteer for the Hawaiian Humane Society, but Dinah Maru figures she'll take that chance.

A few weeks ago, she and her 9-year-old daughter, Kiana, brought home three kittens and their mother, all refugees from the world of abandoned animals. As new foster care volunteers, the Marus are charged with raising the animals until they're healthy enough for adoption.

That's when they have to give back the kittens.

"I am sure they are going to make wonderful pets for someone," said Dinah Maru, who can't promise she won't grow attached to the cats she and her daughter have already named. "This is not something you do for yourself. It reaches out to so many other people to give happiness to so many."

But the Marus can count on a steady supply of other foster pets in their Hawai'i Kai home.

Not only are their numbers on the rise, but May and June are a time of year when the number of newborn cats typically spikes. It's also the season when the humane society feels its need for volunteers is most dire. Fifty additional volunteers are needed to bolster the 110 people already listed, said Alicia Maluafiti, community relations director for the society.

Early summer is a tough time to find volunteers for this kind of work because of graduation and summer vacations, Maluafiti said.

"We have a lot of trouble finding people to take the animals," she said. "People come and go. They travel. The way I see it is we are going to be short volunteers as soon as the kittens start coming in."

The number of animals in need of foster care has risen since 2005, when the humane society handled 721 foster pets. Last year, that number rose to 909, a total that includes a case of 60 pets placed in foster care because of cruelty.

Not all the foster pets are newborn kittens. The humane society also receives dogs, bunnies and guinea pigs, Maluafiti said.

"These animals are orphaned, they are sick or they are injured, so we need to foster them until they are mature enough or healthy enough to be adopted," she said.

Some are strays trapped by the public and brought to the society's Mo'ili'ili facility. Other animals have been brought by owners who are no longer able — or willing — to care for them.

In one recent case, an owner turned in a dog with an infected leg that had to be amputated. The dog will require a foster home to recover and a caregiver with a flexible schedule to meet vet appointments.

A foster home is critical because an animal with a weakened immune system is at risk of illness, even if it's kept with healthier animals, she said. But if more volunteers are found, the humane society may also place animals with behavior and socialization problems into foster homes, Maluafiti said.

Nearly 6,000 cats and dogs are adopted each year. Many of them have spent time at Lu Seyfer's Wai'alae Iki home. She and her family have been foster pet volunteers for 20 years.

The 70-year-old real estate agent and grandmother said she loves the kittens, which provide a stream of furry temptation. She's nursed hundreds of them and jokes that she will die with a litter box scooper in her hand.

"These animals need a chance at life," she said. "If someone can't care for them, they are going to be destroyed."

Seyfer recently returned a litter to the humane society.

"They were so cute," she said. "I would love to have been able to keep all four. Some kittens are just so personable. They would follow me around. They would jump in my lap. They purred. They loved to play."

It was tough. She was smitten by the kittens.

"They were very tempting to keep," she said. "But that's not rare at all."

Reach Mike Gordon at mgordon@honoluluadvertiser.com.