The court was told that the first attack occurred early on April 18, 2010, while McDonald was at a party.
He became involved in an argument and the pitbull, under his supervision, began to circle the group.
He called to it to attack a man he was fighting with, saying "get him, get him".
When the dog did not respond, McDonald kicked it and guided towards the victim, the court was told.
The dog bit the man's legs several times and dragged him across the road.
The victim was hospitalised for 10 days and needed extensive medical treatment including skin grafts.
The aggravated assault offence occurred on October 26 last year while police were arresting one of McDonald's friends.
The pitbull was on a chain and police asked McDonald to ensure it was secure because it kept slipping down over its head.
When it became clear the police officer was going to conduct a background check, McDonald began loosening the chain so the dog could get closer to the officer, and then pulled it back again.
He did this a number of times which caused the dog to become more agitated and aggressive.
As the officer backed away, McDonald again let the animal move closer and the officer had to pepper-spray it. The dog then lunged at the officer and he was forced to jump a fence into a garden to save himself.
The pitbull was involved in another incident that night outside McDonald's home when he had an argument with his partner and several other people.
Enraged, McDonald commanded the dog to attack his partner, saying: "seig em up". As she backed away, the dog bit her on the right leg and held on. Her friends tried to pull her inside the house but her leg got caught in the ranchslider and the dog continued to bite her while McDonald encouraged it.
The woman suffered a 3cm by 5cm gash to her leg but was reluctant to make a complaint because she did not want him charged, the court was told.
McDonald's lawyer Glenn Barnett said McDonald was suffering psychological issues and had suffered a serious head injury as a child, which ACC records would confirm.