A month or so ago, a fence went up around an empty lot in Mantua, makeshift shanties were built, and horses suddenly appeared there, an animal-cruelty investigator said.

Four emaciated horses were seized from the lot on Ogden Street near 40th yesterday and taken to the headquarters of the Pennsylvania Society for the Prevention of Cruelty to Animals for examination, said George Bengal, director of law enforcement for the agency.

The animals belonged to "squatters," Bengal believes, but investigators don't yet know who they are.

The horses were seized after PSPCA investigators obtained a warrant and are now in "protective custody," Bengal said.

If the owner or owners are found and sign over ownership of the steeds, they will be put up for adoption, he said. No charges have yet been filed.

When agents acting on a tip found the four horses, the animals had no clean water or feed and were without adequate shelter, Bengal said.

The horses couldn't get into the makeshift shanties for shelter because of several feet of feces mixed into the mud in the field from recent rains, he said.

They also had a hoof disease caused by standing in water and manure, Bengal said.

He said investigators had been working on the case for about a week, after receiving complaints about the condition of the animals.

The PSPCA has seized several other horses it said were being kept in poor conditions in the past few years, most of them in Strawberry Mansion.