As much as the sentence would sting, counsel Sarah Saunderson-Warner said, the publicity would be punishment in itself.
Macdonald was working the night shift at a rendering plant in Mosgiel on September 23 last year.
Ms Saunderson-Warner said the man's employer had bought two traps and said he wanted the cats "gone by the end of the week".
There were no instructions as to how the animals should be euthanised, she told the court.
According to court documents, Macdonald would take the traps containing cats and submerge them in a large blue plastic bin filled with water.
He would return a few minutes later, removed the trap and discard the carcass along the boundary of the property.
Over the course of one evening, Macdonald killed eight cats, the court heard.
Three days later the SPCA were informed of the defendant's actions by one of his colleagues and executed a search warrant the following day.
A vet carried out a post mortem on six of the cats.
Three of them were found to be pregnant, with a total of 11 kittens.
The vet said drowning was inhumane because the animal took a significant amount of time to lose consciousness and suffered ''severe distress''.
It took minutes rather than seconds to cause death, they said.
Crown prosecutor Richard Smith, on behalf of the SPCA, accepted Macdonald had pleaded guilty immediately and was "entirely co-operative" with investigators.
When questioned, the defendant said drowning was the only method he could think of when it came to killing the cats.
He accepted he should have thought more about his actions.
Ms Saunderson-Warner said her client had been working his whole life without any disciplinary issues.
He had received a formal written warning for last year's conduct, but remained in the same job, she said.
Judge Turner accepted Macdonald's actions were not excessively brutal or callous.
As well as the fine — which would go to the SPCA — the defendant was ordered to pay $610 in costs and reparation.
