No verdict will be made in the James Gray trial until May, Bicester Magistrates Court has heard today.

The trial has been adjourned for today due to the ill-health of Gray’s expert witness, vet John Parker, but will continue until Wednesday next week.

The trial must then adjourn until 2 and 3 April, when both defence and prosecution will make their final submissions.

District judge Andrew Vickers will deliver his verdict on 8 May at Oxford Magistrates Court.

James Gray, 45, of Spindle Farm, Chalk Lane, Hyde Heath, is one of five defendants facing 12 charges under the Animal Welfare Act.

He and the others – Julie Gray, 41, Cordelia Gray, 20, both of Spindles Farm, Jodie Gray, 26, of Park Road, Ashford, Middlesex, and a teenager who cannot be named for legal reasons – deny all the charges.

Yesterday (12 March) Mr Parker, the former chairman of the Royal College of Veterinary Surgeons, said he believed the horses at Spindle Farm could have died from a condition called cyathostomiasis – a serious infestation of worms.

RSPCA officers found 31 dead horses, ponies and donkeys at the farm when they attended in January 2008. A further 115 were later removed.

Robert Seabrook QC, prosecuting, suggested it was “impossible” for so many animals to die in such a short space of time but Mr Parker said they could have died within 48 hours of contracting the infestation.

He said if this was the case it would be “one of the largest outbreaks ever recorded” if properly documented.

But he added: “I am giving the hypothesis that’s what killed the animals, but we cannot prove that because unfortunately evidence has gone.”

Mr Parker told the court evidence from vets and RSPCA inspectors heard already had been “exaggerated” and “overstated”.

Mr Seabrook said Mr Parker had not mentioned cyathostomiasis anywhere in his report on the findings – which amounted to 73 pages.

The vet replied: “My remit until April 4 was not to do with diagnosis. It was to see some horses and see how healthy they were.”

The trial continues.