(CNN) -- Investigators recovered the remains of more than 500 animals after executing a search warrant Wednesday at a home in the Feltonville section of Philadelphia, Pennsylvania, according to the city's chapter of the Society for the Prevention of Cruelty to Animals. The animals included "dozens of sheep, goats ... every type of farm animal you can think of," the Philadelphia SPCA's law enforcement director, George Bengal, said. The SPCA believes two sets of remains are those of small primates, possibly monkeys.