He has a shortened life expectancy but has refused to find out by how much as he wants to enjoy life with his wife and children.
Doctors in New Zealand say it's too risky to operate and have told him he has to live with the condition.
But he has found a top brain specialist in Germany who is willing to perform possibly lifesaving surgery.
He needs to raise at least $100,000 in seven weeks.
Mr Ritchie and his wife were watching a documentary about Hamilton police dog handler Blair Spalding, who had surgery for a brain tumour at the International Neuroscience Institute in Hanover.
They started researching the clinic and contacted doctors there, who said they would do the operation. But the Swiss specialist, Professor Anton Valavanis, is able to do it only on August 12 when he is in Germany for two days.
So on Friday Mrs Ritchie started a fundraising campaign to get the money in time.
Her page on the Give A Little charity website already had $11,482 by yesterday afternoon.
"My appreciation is huge," Mr Ritchie said. "It's really humbling to know that there's such great people in my community."
The couple, who live in Patumahoe, near Pukekohe, have two children, Alex, 8, and William, 4.
Mr Ritchie has tried to live as normal a life as possible, coaching Alex's soccer team and going to work every day at Mercury Energy, where he is a resolutions co-ordinator.
There are risks involved with the surgery but Mr Ritchie said: "If I can still be able to talk to my children at the end of it, it's all worth it."
Mrs Ritchie said she was "absolutely terrified" about the surgery but was getting through with the support of friends and family.
She had explained to her children why their father has seizures but not the severity of the situation.
They have become used to seeing him collapse.
"They stand beside him and rub his belly," Mrs Ritchie said. "We've never, ever discussed with them the fact he could die."
Arteriovenous malformation
*An abnormal tangle of blood vessels in the brain or spine.
*Some have no specific symptoms and little to no risk, others cause severe and devastating effects when they bleed.
*Treatment options range from conservative watching to aggressive surgery.
*Robbie's is in the right frontal parietal lobe of his brain and is the largest and most dangerous form of AVM.
*Surgery option in Germany but he needs to raise $100,000 in seven weeks.
To donate
http://tinyurl.com/n26hpj4
