Last-minute preparations are under way for the Mutt Strut, Suffolk Humane Society’s biggest fundraiser of the year.

“We’re going to be frantically pulling together all kinds of details,” said Kay Hurley, community outreach coordinator for the Suffolk Humane Society. “But it’s all good, because we have tremendous support.”

In recent days, tents have gone up at the Sleepy Hole Park field, and a volunteer orientation has been held. Now, society volunteers are hoping it doesn’t rain.

“This is our primary fundraiser of the year,” Hurley said. “The money we raise at this event is how we support all of our programs throughout the community.”

The Mutt Strut will be held from 1 to 5 p.m. Sunday at the park. It includes a pledge walk — the main money-making portion of the event — doggie demonstrations, canine contests, vendors of people and animal products, children’s activities and more.

“We want lots of people to come out,” Hurley said. “If you can’t come out, be a virtual donor. If you love pets, please make a difference for the ones who aren’t so lucky.”

Another part of the event that will bring in money for the society is the silent auction.

“We are still adding things,” said volunteer Rhonda Jones, who is coordinating the silent auction.

More than 70 items will be available for bid, including large items and baskets of small items. The choices range from doggie gift baskets, fancy water bowls and automatic litter box cleaners to people-friendly things like restaurant gift certificates, YMCA memberships and rounds of golf.

There’s even a basket from a salon that includes hair products for both people and dogs.

There’s also quite a selection of artwork, Jones said.

Bidding will begin at 10 percent of the estimated value. There is no minimum bid increment, Jones said.

“Last year we made almost $1,000 off the silent auction,” Jones said.

Bidders also do not need to stay through the end of the event to win. Bidding will be by number, rather than name.

“Sometimes we get competitions going,” Jones said. “It’s just a lot of fun. I’m planning on bidding on quite a few of them myself.”

For more information on the Mutt Strut, visit www.suffolkhumanesociety.com.