LANCASTER, Pa. (WHTM) – The Lancaster County SPCA says no charges will be filed in connection with a sick puppy discovered by a rescue group this week.

SPCA director Susan Martin said it cannot be proven beyond a reasonable doubt that the breeder intended to harm the puppy or willingly neglected to care for him.

In a news release Friday, Martin said the 4-month-old Boston terrier was bred at the farm where it was discovered Monday. She said the puppy was healthy and vaccinated before it was sold.

Two weeks after purchase, however, Martin said the buyer returned the puppy when their veterinarian determined it had demodectic mange, a skin disease caused by mites. She said the breeder immediately contacted a veterinarian, but the puppy wasn’t responding to medical care.

The Lancaster County SPCA confirmed the puppy was under veterinarian care when it was obtained by the rescue group. Martin said the breeder indicated the dog had gone downhill significantly in the 24 hours before the rescue group obtained him.

The breeder also willingly surrendered the sick puppy’s mother. Martin said the SPCA began treatment of the beginning stages of mange of the mother on Friday. She will remain in foster care and be placed up for adoption once she begins responding to treatment.

The puppy, named Libre by the Speranza Animal Rescue in Mechanicsburg, is in the care of the Dillsburg Veterinary Center. A veterinarian there said in addition to mange, the puppy has a severe bacterial infection and was very dehydrated.

Veterinarians on Friday said Libre is making progress, eating and drinking more, but still in critical condition. Dr. Amber Crow said his life-threatening condition is not something that could have happened overnight.

“At what point do you look at this dog and realize he’s not doing so well?” Crow said. “I mean, it doesn’t happen overnight. This is a slow process and it’s unfortunate outsiders had to step in to start this chain reaction of helping this dog because another day, I don’t know if he would’ve made it.”Get breaking news, weather and traffic on the go. Download the ABC27 News App and the ABC27 Weather App for your phone and tablet.