A heartbroken family is calling for tighter regulation of anti-freeze, after their treasured pet cat Tobias was poisoned.

Natasha Castell, 31, noticed something was wrong when she returned from a day trip to Norwich last week with partner Ryan Thirlwall, 32, and their two young children.

Their cat, aged three, had his head pressed up against the sofa when they returned on the afternoon of September 29.

'We thought it was odd, but cats being cats we didn't think too much of it,' said Miss Castell, who lives in El Alamein Way, Bradwell. 'We tried to pick him up and he cried and I knew something wasn't right.'

She said Tobias, whose nickname is Bibble Bubble, has been inseparable from her son Harrison, seven, since he was a kitten, and daughter Ava, four months, was also fond of him.

They took Tobias to Haven Vets in Southtown.

After blood samples were taken it became apparent that he had swallowed anti-freeze, and it was slowly killing him, crystallising in his kidneys.

In a last effort they took him to a specialist in Newmarket, but found he was too weak for a kidney transplant and nothing could be done.

They refused to put him down until he was overcome by the anti-freeze, and took him home last Friday to cherish his final days. 'He's eating and drinking, going to the toilet and wanting to go outside,' revealed Miss Castell. 'It's heartbreaking. They were our kittens.

'We had them from birth and were present when they were born.'

She said she did not know if Tobias was deliberately fed anti-freeze, or if it had been spilt by someone topping up the levels in their car.

But she said it would only have taken a teaspoonful for his kidneys to glow on the ultrasound scan, and the sweet-smelling substance was irresistable to cats.

'I don't think people realise, whether it's deliberate or not, the amount of devastation they cause a family, as he's a member of our family.'

Miss Castell added: 'There are lots of cases and we think if anti-freeze is not being used properly, is it something that should be on the shelves or should it be restricted to garages so there's a proper way to clean any spillage?'