One of four pugs found abandoned outside shopping malls in Nanaimo, B.C., suffers from a serious kidney infection. (CBC)

Animal protection officers in Nanaimo, B.C., are looking for a suspected puppy mill owner after four pugs were found abandoned outside various city malls last month.

The adult female pugs were all in poor condition, mostly covered in urine and feces with ear mites and worms, Graham Arnold, an animal control officer with Nanaimo Animal Shelter, said Monday.

"They were the offshoot of someone having a backyard or basement puppy mill, where they just bred enough puppies to help pay the bills and support themselves," Arnold theorized.

Animal control officers found the first dog outside on Dec. 13, while the other three were picked up in the ensuing two weeks at other mall locations.

Authorities are still trying to find out who abandoned the dogs, Arnold said.

Graham Arnold, an animal control officer with Nanaimo Animal Shelter, says whoever abandoned the pugs will likely get away with it. (CBC)

"They were all dropped off at nighttime or under the cover of darkness, you might say," he said.

"No one has any descriptions of any of the people that did drop them off, so finding those persons to prosecute them could be very difficult."

The British Columbia Society for the Prevention of Cruelty to Animals has said puppy mills are becoming a growing problem in the province.

A puppy mill refers to an operation where dogs are continually commercially bred to produce as many animals as possible. It is not illegal in B.C., but animals must be kept in good condition, or breeders can face cruelty charges.

Arnold said whoever is responsible for leaving behind the four pugs will likely get away with it.

"The sad thing is they could have just brought them here to the animal shelter or called us, and I would have gone to pick them up, and they didn't have to take them to the mall to drop them off."

Three of the pugs have been adopted. The last one, which is being treated for a serious kidney infection, will also have a new home soon, Arnold said.