An Amish kennel owner in New York has pleaded guilty to inhumane destruction of animals for using a makeshift gas chamber to euthanize dogs with carbon monoxide.

A federal report says 45-year-old David Yoder of Romulus euthanized 78 dogs and 15 puppies by putting several at a time into a wooden box and piping in engine exhaust.

The Seneca County Sheriff's Office charged Yoder after an SPCA worker came across the U.S. Department of Agriculture report.

Yoder pleaded guilty Friday in Romulus Town Court. He has been fined $300 and will also have to pay a $205 state surcharge.

Yoder told investigators he believed his method of euthanizing dogs was humane. The USDA report says Yoder was told to have a veterinarian destroy unwanted dogs in the future.