For context, here is a picture of the "cute little" chihuahua in question - Sabel.
Don't be fooled by Sabel's innocent demeanour, because the furry four-legged embodiment of evil is more cunning, vicious and diabolical than every Get Smart and James Bond villain combined.
Sabel is responsible for the two worst crimes to be committed in Tom's household over the past two years, and probably the two worst crimes ever committed by any chihuahua in the history of the known universe.
Two years ago Sabel - who sleeps on the edge of the bed when Tom and his wife go to sleep - fancied a midnight snack.
Not wanting to travel all the way to the fridge, Sabel decided to munch on something a little closer to home. The big toe of Tom's right foot.
Tom has diabetes so doesn't feel his feet too well, according to Brown, which is why he failed to put a stop to the rogue pet. That's where everything started to go wrong.
"They've got the cute pet chihuahua called Sabel which sleeps on the bed and a couple of years ago he (Tom) woke up and there was blood all over the bed and he didn't know what had happened," Brown told SEN Afternoons on Friday.
"So he looked down and he was missing his right big toe - it was gone, completely gnawed off.
"They called the ambulance, went into hospital and spent about two weeks in hospital because they needed to amputate the big toe and do skin grafts and what not.
"He (Tom) wasn't happy - he suggested putting the dog down. His wife said, 'We'll putting you down before we put the dog down' so he had to just grin and bear it."
Fast forward two years and - as SEN host Francis Leach said - like a serial killer biding their time, Sabel struck again.
She had lured his unsuspecting victim into a false sense of security for so long, now it was time to pounce.
That spelt bad news for Tom.
"Two years later - Sabel had done nothing wrong in that two year period - he woke up on Thursday morning with no big toe," Brown said as both he and the radio presenters laughed uncontrollably.
"They went to hospital again, going through the whole process of amputating the toe, skin grafts. He was in quite a bit of pain.
"I think Sabel is not going to be put down because we don't believe in that but going off to a farm, to a good home I think.
"That is a legit true story."
Brown posted his father-in-law's gruesome injuries to Twitter. A word of warning, once you see these images you can never forget them.
Brown said Sabel ate the nail, flesh and bone of the affected toes, but could only see the funny side of it all.
"It's a funny story, too good a story not to put on Twitter," he said. "I'm just glad he doesn't sleep naked because that could have been a real tragedy.
"Now the dog's just taking the piss."
After a stint in hospital most people can't wait to get back into their own bed for a good night's sleep. It's safe to say Tom is no longer one of those people.