Judge McDonald said Godfrey did not seek advice or carry out research before putting the rubber ring on his female six-month-old pitbull terrier-type puppy named Rogue.
He said research had proven that animals suffer acute pain for 90 minutes after the ring placement. Godfrey's actions had long-term consequences and health problems for Rogue, the judge said.
The dog had to be heavily sedated, and its tail below the rubber ring was amputated by a veterinarian.
A summary of facts stated that acting on a complaint from the public, an animal welfare and a field officer, accompanied by a police officer, went to a house Godfrey lived in at Kamo on August 12, 2013. The puppy's tail was swollen and her ribs and hip bones were visible.
In explanation, Godfrey said he placed the ring three days before the visit by the officers because he wanted to shorten the tail.
In court, he said through his lawyer John Watson that he had seen neighbours do it and didn't think it was illegal.
Mr Watson submitted that a sentence of community detention was appropriate and wouldn't be seen as a "letaway" or a sentence that would enable his client to care for his two children on a part-time basis.
But Judge McDonald said the offence was serious and the pre-sentence report said an electronically-monitored sentence was not suitable.
Outside court, Mr Watson said the penalty imposed was "quite stern" and seemed out of sync with sentences imposed for similar offences.
He has not received instruction from Godfrey on appealing the sentence.