EMMAUS, Pa. -- Agents with the Pennsylvania SPCA entered a Lehigh County dog kennel shortly after 1:30 p.m. in what some believe could be the largest puppy mill raid ever in the state.

Agents were executing search warrants at the Almost Heaven Kennel in Emmaus, near Allentown, this afternoon after a two month undercover investigation reportedly showed inhumane treatment there.

The kennel specializes in breeding poodles and Labrador retrievers. In August, the business had 508 dogs at the property on Chestnut Street, state records show.

The owner of the kennel, Derbe Eckhart, has a long history of run ins with state and local authorities and has been convicted at least twice of animal cruelty.

"Early reports show that conditions are horrendous," said Howard Nelson, president of the Pennsylvania SPCA moments after agents entered the property.

Agents, he said, were reporting filthy living conditions and that they witnessed several dying puppies and dogs with bad skin conditions.