Distraught Alada Murray and other family members were powerless to prevent their three cats suffering an agonising death from suspected poisoning in the same 24 hours.
Akira, Callie and Leonidas had to be put to sleep when they were taken to the vets.
Blood tests confirmed that they had anti-freeze in their system.
Alada also told the Leader that two other cats on the same estate in the Scotland Gate area of Choppington – Harley and Whiskers – died just days later after having the same substance in their system.
She said: “My three cats one after the other were very sick and wobbly on their feet.
“It was heartbreaking to take each one to the vets separately and be told they had to be put to sleep because they had anti-freeze in their system.
“Two of my children are autistic, so it was very difficult to explain it to them.
“We’re shocked that this has happened. Neighbours I’ve spoken to appreciate the cats on the estate because they catch rats coming from the nearby field into the estate, but now those with cats here are being vigilant after the death of five in such a short space of time.
“Anti-freeze needs to be caught very quickly to give your cat any chance of surviving. It still may not be enough to keep them alive, but I would urge cat owners to take their pets to the vets if they are sick or something doesn’t look right.
“You may think it’s just a hairball, but it’s not worth the risk.”
Anyone with information about the deaths of these cats is asked to call Northumbria Police on 101 and quote reference number 558 19/09/18.