"I noticed that the vision in my left eye was becoming quite bad. I said to my father 'I can't read the number plate on the car in front of us'," he said.
"We went to the eye specialist to check it out, and that's when they saw there was a tumour in my brain which was stopping brain fluid draining down my spine."
The tumour was surgically removed, followed by radiation treatment. He was left with just 60 per cent vision in his left eye.
Mr McDonald went to Dunedin in February this year for a less invasive radio surgery treatment which removed the latest tumour.
Mr McDonald says the rejection from prospective employers is even harder to deal with than his battles with cancer.
"With cancer at least you are making progress ... you get a lot of support as well and you can see yourself getting closer to your goal and there's always something happening, there's activity," he said.
"But with trying to get a job you're just sitting around, just sending emails, calling people and then the next day you might get another 10 emails saying 'sorry you haven't been given a go'."
"You get really tired of it, it's been almost a year of constant rejection."
He said he would consider moving overseas and had applied for jobs in Australia and Britain.
"I just want someone to give me a go but everyone's saying they want people with experience.
"I had an interview with an accounting firm three days ago and they gave me some feedback and they said I wasn't selling myself enough."
Institute of Chartered Accountants chief operating officer Kirsten Patterson said the accounting job situation was flat before Christmas but there was optimism in the market for next year.
"A third of our corporate sector accountants in the larger teams are expecting to increase their staffing levels in the next year," she said.
Ms Patterson said graduates often focused too much on their academic transcript and didn't give the employer a picture of themselves as an individual.
"They need people who are going to be contributing to the staff cultural environment, they need people who have got really good networking and socialising skills."