Vet Micahel Kettle, who runs Marshlands Vets, is urging owners to be vigilant and call police if they see anyone acting suspiciously.
He said: “I believe it is malicious and this now needs to be taken very seriously.”
Heartbroken cat lovers Emma Hibbert, 31, and husband Ian, 42, lost both their cats, Gibbs, two, and one-year-old Sherlock, after they were both poisoned with antifreeze.
Sherlock was killed in August 2014 and Gibbs died on July 20 this year.
Mum-of-five Mrs Hibbert said: “When I found each of them convulsing I took them to the vets straight away.
“The vets ran tests on them and found crystals in their kidneys, which is a sign of antifreeze poisoning.
“Their kidneys had already shut down and they both died.”
Her neighbours Claire and Glynn Gray have lost six cats over the last two years to the poisoning.
Mrs Gray, 37, said it feels “like an attack on the family”.
She said: “I don’t know how someone could be so evil – they’re killing more and more each year.”
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