Ian, 56, who uses the surname ‘Catmando’, lives with dozens of felines in a small terraced house in Portland Terrace, Gainsborough, and claims he trains them up to help people with epilepsy.
Ian says he spends more than £5,000 a year caring for his pets and has looked after more than 5,000 cats since 1992.
But he is now at the centre of an RSPCA probe after animal rights activists gathered outside his home last week to stage a protest over concerns for the cats' welfare.
They say the pets cannot roam free because the back garden is covered with chicken wire, barbed wire and metal bars.
But unemployed Ian says his pets are happy and healthy and he has trained thousands of cats over the years without any complaints.
Ian, who is not married and has no children, said: "I’m a professional cat carer and have been since 1992.
“I’ve looked after over 5,000 cats and trained up 2,000 as alternative treatments for epilepsy.
"Cats can recognise when someone has an epileptic fit coming, sometimes hours in advance.
"I don't drink, I don't smoke, I don't chase women. I sit down with the cats and it takes it all away - plus a room full of cats keeps it warm.
“If you have 30 cats in a room that is minus five centigrade, within an hour the temperature is well over 20 degrees.
"Everything is legal and above board. I'm a good person. I'm taking a stand because I have done nothing wrong.
"I am squeakier clean than a bar of soap. I’ve got no criminal records and no mental illness at all.
“There’s enough room for the cats and I have the police in the property on a regular basis.
“They have all said the same: the cats are all healthy and there is nothing wrong with them.
“I just love cats."
Ian has hit back at the protesters who have been gathering on his street daily and says that the stress caused one of his cats to have a miscarriage.
He added: "One of the female cats was pregnant with seven kittens and she’s miscarried. The other cats are seriously stressed out.
"The protesters reckon it is illegal and immoral to train and walk cats. That’s stupidity, what’s wrong with walking cats if people walk dogs?
“At the end of the day, if you could pick on people who walk cats, who is it going to be next?
“Hamster walkers, gerbil workers, tortoise walkers? What's wrong with individuality? What's wrong with freedom of choice?
“There's nothing wrong with doing something the old-fashioned way."
Ian says he also tours about the country with some of his cats in a cart as a showman, keeping up his family tradition.
He added: “My father was a showman and my grandfather before him.
“I let people cuddle the kittens and bring happiness and hope.
“I’ve always had cats and at some points I’ve had up to 140.
“I spend £5,000 a year on them in food, treats, toys and treatments.
“I’ve just bought six chickens, 5lbs of gammon, 5lbs of sausages, 5lbs of bacon and £5lbs of chicken nuggets.
“That’s £70 of food and just for one meal for them which I get every day if I can.
"My cats are well looked after. People cannot go around making allegations about me - the allegations are pure fantasy."
Lincolnshire Police have warned protesters to stay away from the property so that the relevant authorities could do their jobs.
West Lindsey Community Policing Inspector Gary Brockie added: “Officers along with an RSPCA Inspector and a housing officer from West Lindsey District Council attended the address at Portland Terrace.
“This is not a police-led investigation however, we continue to work with and support the RSPCA who have the relevant information and expertise.
“My request is that those who have previously felt the need to gather in the location to please stop doing so as this will support the relevant agencies to conduct their enquiries into this sensitive incident in an unhindered manner.”