It wasn't clear whether the dog ranger had been punched or head-butted, but he had suffered injuries described by a colleague as minor to moderate.
He had seen a doctor as a precaution.
The council had seized the dog after it allegedly attacked a person, giving the owner seven days to claim it, failing which it would be put down.
There was no response from the owner, and it was duly destroyed.
"Fortunately incidents such as this are few and far between, but when it does happen, rest assured there are likely to be consequences," FNDC chief executive David Edmunds said earlier this week.
"It need not go as far as physical assault.
"If there is a history of verbal abuse or threats we may still place the matter in the hands of the police or relevant authorities.
"This prison sentence shows that not only the council but also other authorities take these matters very seriously.
"Staff members have the right to feel safe in the workplace and while carrying out their duties in the field. There really is no excuse for members of the public to attack or threaten them."
In the majority of cases staff subjected to threats of violence or abuse were simply enforcing the law, or in some cases were actually trying to help the persons involved.
"The job is hard enough, and often under trying circumstances, without having to contend with unwarranted abuse or threats," Mr Edmunds added.
"In the case of verbal abuse, two warnings to desist are issued. If the abuse continues the staff member involved is instructed to terminate the conversation.
"We also maintain an active abuse and threats file, and if more than one incident is flagged from the same source the matter is likely to be referred to the council's legal section for further action."
