His wife Vikki, a registered nurse, took his blood pressure and it was ''way through the roof'', Miss Booth (25) recalled.
''He went from literally fit and healthy to nearly dead on the floor. He had no energy at all,'' she said.
At the time, Miss Booth was working for him - he was stock manager at a property in Mossburn in Southland - and could see his day-to-day struggles.
Without telling him, or her mother, she got checked to see whether she would be compatible to give a kidney, and it was ''just a complete fluke' she was a match.
Mr and Mrs Cameron realised something was up when they got a kidney donation pamphlet in their mailbox.
The transplant went ahead on June 27, 2016.
It was during months spent in confinement that Mr Cameron started making saddles, including the one he gave to his step-daughter.
''I gave him a kidney so he gave me a saddle,'' she said.
Mr and Mrs Cameron would be at Wanaka to watch her - and her brother Jimmy Booth, an open bull rider - compete.
Mr Cameron said he was back full-time casual mustering and running his small saddlery business from home.
When he was sick, he struggled to walk 100m.
Now he was back mustering on foot or on horseback, and it was ''nothing to have a two-hour climb out, walking all day''.
He and his wife would be ''very proud'' of Miss Booth and her brother this weekend.
Mr Cameron competed at a rodeo at Labour Weekend but was struggling to get time to compete, due to his work and his saddlery business.
There was a 12-month waiting list for his saddles.
An Organ Donation New Zealand spokeswoman said 69 people received kidneys from live donors in 2017.
''There were also 73 deceased organ donors, and thanks to these donors 118 people were able to receive kidney transplants - many people donated more than one kidney.''
While the number of deceased organ donors had doubled over the last five years, more were needed, she said.