The mother of a nine-year-old boy who was fatally attacked by her friend’s “extremely powerful” dog in a caravan on a Cornish holiday park has been jailed for two years.

Frankie Macritchie was left alone inside the caravan with the dog for more than two hours while his mother, Tawnee Willis, went to a party.

When she returned to check on her son she found that the 45kg dog, an American bulldog crossed with a Staffordshire bull terrier, had attacked him, leaving him with more than 50 bite marks. Frankie died from blood loss.

Willis, 31, from Plymouth, admitted child neglect. Her friend, Sadie Totterdell, 29, also from Plymouth, was jailed for three years after admitting owning a dangerously out of control dog.

The tragedy unfolded at the Tencreek holiday park in Looe, Cornwall, on 12 April last year.

Willis and Totterdell joined friends in another caravan, leaving Frankie alone with the dog, Winston.

The court heard Frankie came to the caravan where the adults were partying at about 2am, saying he was hungry.

His mother took him back to the caravan and left the boy and dog alone while she returned to the party.

At about 4.30am, Willis went to check on Frankie and found him lifeless. The boy’s PlayStation was still on and the court heard it was possible Frankie had raised his voice at a game, leading Winston to attack him.

Judge Simon Carr said: “Winston was an extremely powerful and – as you can see from what happened – potentially dangerous dog. Yet a decision was taken to leave Winston and Frankie in that caravan alone.”

The judge told Totterdell that incidents in the past, including when Winston bit a child who required medical treatment, should have reinforced that he could be dangerous and served as a “red flag”.

Prosecuting, Simon Laws QC said some of the adults at the party had been taking cocaine and cannabis, as well as drinking.

A postmortem examination found Frankie suffered 54 injuries including bite marks, puncture wounds, lacerations, bruises, scratches and drag marks.

In a statement, other members of Frankie’s family said they could never forgive Totterdell and Willis for leaving the boy alone with Winston.

They said: “Frankie was left alone to die in the most horrific way, beyond anyone’s imagination. Frankie was a special young boy. He was funny, caring and kind – his smile would melt your heart. He was always joking around and he loved everyone. The impact of our boy’s passing on us is huge. We are truly heartbroken.”