A warning has gone out to dog owners after a canine died a sudden and “horrible” death after eating what is believed to be poison.

Rescue dog Maggie began staggering, vomiting blue foam and trembling after swallowing a mysterious substance in Kent on Boxing Day afternoon.

Evette Carter’s parents were walking their three-year-old mixed-breed on a lead in Cooper Street Drove in Ash near Sandwich when the incident happened.

Speaking on her parents’ behalf Evette condemned the “horrible cruelty” and said they believe similar things have happened in the rural area.

She said: “My dad and step-mum are grieving, blaming themselves for taking her on a walk that day, it has been extremely distressing.

“My step-mum had her on the lead and saw there was something in her mouth, but the dog swallowed it before she could get it out.

“Maggie began trembling and vomiting blue foam on their blanket and having seizures, she died a horrible death.

“Whoever laid the poison is a cruel person. A vet we spoke with said there have been similar deaths in the area,” she said.

The cat-rescue worker added one vet told the family they believed she was baited with slug poison due to the colour of the vomit.

Toxicology tests to determine the substance will be undertaken in the New Year at the Royal Veterinary College in Kings Cross, London.

Meanwhile the family is calling on dog owners to take extra care.

Evette said: “The police have been notified and so has the RSPCA, they said this isn’t just an issue in Kent but all around the UK.

“We’re desperate to get the word out.”

The charity recently revealed a 73% rise in deliberate and accidental poisonings of dogs in the past five years.

Last year the charity received 368 reports of suspected dog poisonings and this year it had logged 244 cases by September.

This most recent suspected poisoning took place in a public walk-way between Goss Hall and Brook St Farm, where the road meets a bridle way.

Evette told how her parents cherished Maggie, who had a troubled first five months of her life, before they took her in.

She continued: “They did so much to help her. She took a lot of training and they put in so much effort.

“They loved her like a child.”

A police spokesman said: “Kent Police was contacted at 4.23pm on Boxing Day following the death of a dog.

“The dog is reported to have fallen ill after eating an unknown substance in Cooper Street Drove in Ash, near Dover.

“No criminal offences were reported and the caller was advised to contact the RSPCA.”