Former security guard and Royal Navy seaman Steve Bouquet carried out an eight month campaign of brutal knife attacks on pets in the city.
The 54-year-old stabbed at least 16 pet cats and potentially many more, police said.
He killed nine cats, while seven more he left for dead survived.
Bouquet was due to be sentenced today (Monday).
His Honour Jeremy Gold QC told the court Bouquet was not fit to attend court due to a physical illness.
“He is in hospital due to physical illness and not fit to be produced in court this morning.
“I understand the diagnosis was only made at the end of the working week,” the judge said.
Bouquet remains in custody and will appear again on July 30.