A dog's head in a freezer was one of many grisly discoveries investigators made Monday night at a Chester County house that appeared to be a site for ritualistic animal sacrifices.

Rich Britton, a spokesman for the Chester County SPCA, said his agency was contacted by police and executed a search warrant at a house in the 2400 block of Wayne Avenue in Caln Township.

Chester County District Attorney Tom Hogan said the SPCA was called after police had executed a search warrant for an unrelated investigation. "Nobody expected to find what they did," he said."

Britton said he and two animal protective-services officers entered the house's living room, where a gold-leafed animal skull was displayed on a coffee table and a 10-inch animal vertebra sat on a fireplace mantel. Also in plain view were a necklace that appeared to be made of canine teeth and four or five knives and machetes, Britton said.

Two more skulls that appeared to be canine were in the kitchen, along with a drawer of animal bones, four occult books, and a workbench with gold-leafing materials, he said. Investigators found the dog's head in the freezer, Britton said.

"I've never seen anything like this in my life," said Britton, calling the findings "macabre and Dahmeresque" in a "nice, typical suburban" neighborhood.

When investigators confronted Wisconsin serial killer Jeffrey Dahmer in his apartment in 1991, they found a human head in a refrigerator and victim's skulls and other body parts.

In Caln Township, SPCA investigators found a fire pit, charred animal remains, more skulls, a tree with chicken parts and bones hanging from it, and a chicken coop, where two live chickens were rescued, Britton said.

He said police had two people in custody, but Hogan declined to confirm that, explaining that the investigation is ongoing. The evidence gathered by the SPCA has been added to items such as a large safe that was removed from the house during the first search warrant, Hogan said.

"We are following up full speed to figure out where all this information leads," Hogan said.

Contact staff writer Kathleen Brady Shea at 610-696-3815, kbrady@phillynews.com, or @brandywinebits on Twitter. Read her blog, "Chester County Inbox," at www.philly.com/chescoinbox.