Keith and Shauna Morgan, of Brick Township, said they found Sammy (short for Samurai) in a plastic garbage bag last week.
It turns out they own him.
Now, they face six months in prison and a $1,000 fine.
The couple handed over another cocker spaniel to the Monmouth County SPCA on Thursday.
That dog, 3-year-old Ady, showed no signs of neglect and had recently been groomed.
Monmouth SPCA started receiving tips that there was a second dog in the home after Samurai was discovered. They finally had enough evidence to go to the house early Thursday, where the Morgans voluntarily surrendered the dog.
Sammy was found severely dehydrated, emaciated and with a fever. His fur was matted down and covered in filth, his paws burned from sitting in his own urine for so long.
His recovery continues.