After a 40-year stint with the RCMP, Neil Fraser had seen a lot in his career. But as chief inspector for the Nova Scotia Society for the Prevention of Cruelty of Animals (SPCA), nothing prepared him for animal hoarders.

"I didn't realize the number of people that have 20, 30, 50 cats in their residence," Fraser says.

Fraser is one of a number of SPCA inspectors who say they've seen the number of hoarding cases climb dramatically in recent years. In Halifax alone the SPCA say it gets about two calls a week about animal hoarders.

Kristin Williams is Executive Director of the Nova Scotia SPCA. She says her organization can't even keep up with the calls.

"This is not an issue that is restricted by social or economic or political stripes … It is everywhere and it is getting worse," she says.

Three years ago, inspectors with the Nova Scotia SPCA say they encountered one of the worst cases of animal neglect ever witnessed in the province.

Celtic Pets Rescue had been a respected animal shelter run by Zonda MacIsaac outside Port Hastings, N.S., but that changed dramatically on February 2, 2008. Acting on a complaint from a neighbour, SCPA officers entered MacIsaac's house with a search warrant and the scene was nothing short of a house of horrors.

SPCA officers say the smell of urine and feces was overpowering. Officers found 27 barking and yelping dogs and 78 cats with no food in sight -- the animals had defecated throughout the house, many were drenched in their own feces and urine.

As in most hoarding cases where a warrant is required, the SPCA brought along a veterinarian that day. The vet catalogued a litany of ailments -- animals with severe respiratory problems, eye problems, diarrhea and generally "appalling living conditions from neglect."

Zonda MacIsaac eventually pled guilty to animal cruelty and was banned from owning or working with animals for 20 years.

MacIsaac has never spoken publicly to the media before, but she did agree to talk to W5.

"I don't feel I'm a criminal. I feel I'm somebody who my heart was in the right place. I love animals. I would never hurt anybody or anything or any animal. I got overwhelmed."

Asked why she misled the SPCA initially about just how many animals she had in her care, MacIsaac says "I was afraid that they would kill them, that they would kill them as a group. They would take them, put them in the gas chamber…I didn't want to be responsible for that."

To this day, MacIsaac insists she is not an animal hoarder. "I've been assessed up the wazoo and based on everything that had happened and all the documentation and everything put together, they say that I am not a hoarder."

Maybe not according to health care professionals, but the people that look after animals don't agree.

Williams, executive director of Nova Scotia SPCA, says "I recognize that she doesn't feel she is, but the truth is that she is."

Williams says that it's almost impossible to detect animal hoarding until it has spiraled out of control. "It's very well hidden because of the shame aspect. Because of the denial, hoarding remains very hidden. You can be living next door to someone who's hoarding and not even be aware of it."

Elaine Birchall is an Ottawa-area social worker and one of the few professionals in Canada who treats hoarders of all kinds, including animal hoarders. She says that animal hoarders tend to have very damaged lives. "Their trust, their primary relationship isn't with their own species. It's with another chosen species," she says.

Birchall says they tend to be "people who want absolute control, sometimes in a kind and loving way. But it's still absolute control and there's an element of narcissism because it's all about them."

One thing is certain. Animal hoarders know how to disguise their addiction. Some even set up pet rescues to collect more animals. Birchall says "I don't believe that most pet hoarders, animal hoarders, who end up calling themselves pet rescuers set out to have that many animals. But the problem is there's no off switch. There's always another emergency."

Birchall says legitimate rescue operations "have a group of people outside of their own personal interpretation and preference that dictates policies, dictates limits…and they have foster homes for these animals…You really need to question when it all boils down to one person."