Investigators from the Ontario Society for the Prevention of Cruelty to Animals rescued 100 mistreated and sickly dogs from an alleged puppy mill in the province's Georgian Bay region, northwest of Toronto.

The OSPCA rescued the small-breed canines, ranging from puppies to elderly dogs, from a home in Meaford, Ont., near Owen Sound on Monday night.

The house was covered in "feces," Ontario SPCA spokesperson Alison Cross told CTV Toronto on Tuesday.

One veteran investigator said it was the worst odour she had ever smelled.

Many of the severely matted dogs were suffering from open wounds and possible infections along with a host of other complications, Cross said.

The 100 pups were all brought to the York regional SPCA facility in nearby Newmarket, later that same night. The dogs are receiving much-needed medical attention, Cross said.

It is expected that many of the dogs will require long-term veterinary care.

It's still too early in the investigation to put dogs up for adoption, but the SPCA promised to let the public know when it's time to find the pets a permanent home.

"I saw this on CTV News last night...I knew there was a great need for support and help so I'm here to do whatever is necessary," Linda Weir, a local volunteer, told CTV Toronto on Tuesday.

The rescue was one of the largest ever made by OSPCA. The organization said it was tipped off by a concerned citizen.

The names of the homeowners have not been released and charges are pending in the ongoing investigation, Cross told ctvtoronto.ca on Tuesday.

If convicted, the accused could face up to two years in prison, a $60,000 fine and lifetime ban from pet ownership, she said.

With a report by CTV's Matet Nebres