LOS ANGELES — People want their dog to be a friend, not afraid.

But sometimes, fear grips dogs so tightly they shake, cower, bite, growl or pee. It can be constant, painful and hard to overcome. Such dread can consume a dog when it’s freed from a cage at a puppy mill or hoarder’s home because that’s the only life the dog has ever known.

Until now, it was up to animal shelters to ease the fears, knowing if they didn’t, euthanasia was the likely alternative. But recently, the American Society for the Prevention of Cruelty to Animals opened its Behavioral Rehabilitation Center at St. Hubert’s Animal Welfare Center in Madison, N.J.

It’s a two-year research project being financed by the ASPCA.

For now, dogs seized from puppy mills and hoarders will be the primary patients, said Kristen Collins, ASPCA’s director of anti-cruelty behavior rehabilitation and director of the center. It will include some dogs that have been confined for long stretches as evidence in court cases.

Dogs will come from shelters across the country as well as from seizures involving the ASPCA.

It’s groundbreaking and exciting, Collins said. “It’s the first-ever facility that’s dedicated strictly to providing rehabilitation for dogs that are victims of animal cruelty.”

The research also will provide some numbers, Collins said. No one knows how many shy dogs are being placed in homes now. And little is known about how they fare after placement, so center staff will spend a lot of time following up on animals.

There are 27 kennels, an office, real life rooms, treatment rooms and common areas at the center.

The average stay for most will be six to eight weeks, “but we don’t have a hard and fast rule. All dogs are individuals. We will be flexible,” Collins said.

A team of 10 people, including two behavior experts from St. Hubert’s, will staff the center. Volunteers and daily caretakers will feed the dogs and clean kennels.

Graduating dogs will return to a shelter for placement and ASPCA shelter partners will continue working with the dogs if needed, Collins said.

St. Hubert’s is a longtime disaster partner of the ASPCA and jumped at the chance to be involved, said President and CEO Heather Cammisa.

Fear and anxiety are major factors that can hinder a dog’s quality of life, she said.

“If they are hiding in the back of the cage and they are fearful, No. 1, they don’t have a good quality of life and, No. 2, they are not going to be selected for adoption and when they go home, they are not really prepared to be the family pet that adopters seek, so this is just a win-all-around,” she said.

The ASPCA spent over half a million dollars on the building, Cammisa said, and will pay all other expenses, including vaccinations, spaying or neutering, treatments and other care.

Some of the first dogs at the shelter were part of the 213 Alaskan malamutes seized from a Montana breeder who was convicted in December 2012 of 91 counts of animal cruelty. After being starved and living in filth at the breeding facility, the dogs then had to be kept in kennels as evidence for 16 months while the trial played out.

The dogs were released to a humane society in Helena, Mont., where they were spayed and neutered, and another group helped place the animals.

While some dogs are in malamute rescues waiting for the right owner, many have found forever homes. Sutherland and his wife, Nicole McCullough, adopted one.

When the dogs were in evidence custody, Sutherland would visit to help out once a month. Cinder, a 6-year-old female, became his project.

She is missing the tip of her ear, has broken teeth and a broken toe, injuries Sutherland said were caused when what little food was given to the dogs was thrown over a fence, causing food fights. Many of the dogs are even missing their tongues, he said.

Cinder has come a long way. “We took a shy dog, and she’s all grins and giggles now. If you work with these dogs, they rise and shine,” Sutherland said.

The center will only be able to handle about 400 dogs during the project’s two scheduled years.