And, on Saturday, at age 72, he was in the saddle again.
Mr McCarthy took part in the team roping event, although his favourite event of all time remains steer wrestling, or "bulldogging".
He gives some of the credit for his longevity in the sport to former world steer wrestling champion, American Jack Roddy.
"When I first went to America, we didn’t know too much about steer wrestling.
"But I met the great Jack Roddy. He was world champion in ’66 and ’68 ...
Proving he learned the lesson, Mr McCarthy became New Zealand’s national title-holder on two occasions in the 1970s and ’80s.
Asked about injuries, Mr McCarthy said he once won the bronc riding at the Mataura rodeo with a broken heart but had otherwise been "pretty lucky".
Mr McCarthy said he enjoyed the comaraderie of rodeos and seeing his children compete and do well.
As to the protest at the entrance to the Wanaka rodeo by eight members of the Queenstown Vegan Society, Mr McCarthy said they were "great advertising" for rodeo, and protesters’ "ignorance is only superseded by their unwillingness to learn".
"If they jumped the fence, came down here and asked a few questions about it, they might change their minds."
Mr McCarthy said he was very proud of the heritage of rodeo in New Zealand.
Most of the rodeo events were completed before heavy rain late in the day.
The crowd was estimated at about 1500.