WESTBROOK — Boomer is a 95-pound bulldog with a head like a basketball.

But his cage at the Animal Refuge League of Greater Portland is more suited to Baio, a beagle one-third as big, who’s in the same size kennel in the next room.

More space for big dogs like Boomer, along with more privacy for cats and a more welcoming experience for humans, is in the blueprints for a larger, $6.5 million shelter that’s scheduled to open by the spring of 2016.

On Wednesday, the Animal Refuge League of Greater Portland announced its plan to build a 25,000-square-foot shelter on land behind its current building on Stroudwater Street, where it has operated since 1956. The new facility will have a modern surgical center, isolation rooms for sick animals and outdoor play areas, among other features.

So far, the nonprofit organization has raised $4.3 million. That includes a $1 million donation from Arthur Girard, a Portland developer and a longtime supporter of the shelter, for whom the adoption center will be named.

The organization is counting on support from the community to raise the rest of the money, and hopes to do so within a year, said Executive Director Patsy Murphy.

The Animal Refuge League cares for more than 4,000 animals each year. It takes in stray and surrendered cats, dogs, rabbits and other small animals, and places them in adoptive homes.

Murphy said the 58-year-old shelter can be uncomfortable for people, and for dogs like Boomer.

“We hear so frequently that people can’t come to the shelter because it’s sad,” Murphy said.

The new building is designed to be anything but sad, configured to maximize sunlight and complete with living room-like areas where animals can be introduced to potential owners.

“It’s warm, it’s welcoming, and adopters can envision the animals they’re meeting and greeting within their home,” she said.

The shelter now has capacity for about 300 animals and almost always operates with that many or more, Murphy said. The new facility, which will be about 10,000 square feet bigger than the three buildings the Animal Refuge League uses today, isn’t meant to take in more animals, but to give them all more space, she said.

The Baxter Shelter is the Animal Refuge League’s main building, named for former Maine Gov. Percival Baxter, who founded the organization in 1911.

First located on India Street in Portland, it moved to a bigger space at the corner of Center and Pleasant streets in 1928 before moving to Westbrook in 1956.

The shelter, which has a staff of 40 and more than 200 volunteers, has expanded into a house next door and offices down the street. When the new facility is built, all services will run out of one building – something that will be especially good for the cats, which make up two-thirds of the animals at the shelter.

Now, cats first come in through the busy reception area, to the sound of barking dogs.

“It’s incredibly stressful for them,” said Sarah Ashe, the shelter’s manager for cats.

After spending a few minutes in the intake room, they’re taken across the parking lot to a house next door, where they’re examined and treated for any medical conditions.

Depending on their health, the cats will stay there anywhere from a day to a couple of weeks before moving into the shelter, when they’re ready for adoption.

“All that sort of movement is not ideal for them, for their mental health and stress,” Ashe said.

When they stay in one building, she said, “smells and sounds stay the same.”

Leslie Bridgers can be contacted at 791-6364 or at:

lbridgers@pressherald.com

Twitter: @lesliebridgers