The number of cats being shot by air guns has almost doubled in the past two years despite new laws to tackle the problem, says the RSPCA.
Barney, 8, was shot in the head and lost the sight in his right eye
There were 11 incidents in January 2006, compared to 20 in January 2008.
But the RSPCA says this is only the tip of the iceberg and for some people, shooting pets had become a "sport".
The recent tightening of the laws on air gun ownership and where they can be used is having little effect, the charity says.
The RSPCA says most incidents are going unreported and it wants gun owners to make sure their weapons are not being used irresponsibly by friends and family members.
Sue Stafford, acting chief officer of the RSPCA, said it was bad enough for owners when their pets were hit by a car, and worse when they were deliberately harmed.
"It can be very difficult for them and especially the children in the family to come to terms with," she said.
"I think it's some people's misguided view of sport and they just completely overlook the fact this is a sentient animal which can suffer and has an owner in a lot of cases."
Samantha Kingdon's tabby cat Barney was shot in the head by an air gun.
He was shot right between the eyes and the pellet is still lodged at the top of his spine.
He was initially blinded in both eyes but has since regained partial sight in his left eye. His owners have been told that if the pellet moves it could cause serious problems.
Ms Kingdon said: "Initially they thought they were going to have to take his right eye out. It was protruding so far out of his skull, his lids couldn't shut around it.
"Other than the blindness and the nervousness, he seems fine but we know it is not necessarily the end of it."
Ms Kingdon said the incident brought their lives to a standstill and Barney's recovery became their main priority. It also cost the family £1,000 in veterinary bills.
"He's eight years old and I've had him since the day he was born," she said.
"He's not a nasty cat, he's actually one of the most friendly cats you could probably ever meet. It's devastating to think someone could do this to any animal and leave them in that amount of distress and pain.
"To see your cat blind, sitting in a steel box at the vets, not knowing where he is and constantly crying. It's heartbreaking."
The RSPA is also concerned about the rise in the total number of air gun attacks on all animals.
There were around 350 investigations in 2006, but that increased to almost 500 in 2007.
In October 2006, the Home Office brought in a range of new measures to tackle the use of air guns, including increasing the age limit for buying or possessing an air weapon from 17 to 18.