Born Kathy Petro, she grew up in a horse racing family from Massachusetts and married a fellow horseman, Tim Ritvo, in 1990.

In spite of the medication regime and immunity issues that transplant recipients face, she lives a normal life as a horse trainer and shows no signs of organ rejection.

[4][5] Tim and Kathy married in 1990 and soon thereafter moved to Florida, which they viewed as a better place to make a living in the horse racing industry.

[3] Since the transplant, Ritvo shows no signs of organ rejection, keeping to a regimen of over 30 pills a day but otherwise living a normal life.

[11] Ritvo's doctors advised her not to return to work in the horse racing industry because of the risks to her immune system posed by the dirt and dust that is part of the environment.

Nonetheless, in spite of medical warnings, she returned to horse training within six months,[10] and was credited for saddling four starters in 2009.

[16] Mucho Macho Man had overcome his own health problems in order to race, including having appeared to be lifeless at birth.

Comparing her own experiences to the horse, Ritvo stated, "From the moment I opened my eyes, I felt fantastic.

[14] Her highest profile race that year occurred when Mucho Macho Man was a close second by a half-length in the 2012 Breeders' Cup Classic.

She entered him in the late September Awesome Again Stakes, where he earned his first Grade I win and free entry fees for the Breeders' Cup Classic.

[21] In response to a reporter's question about how it felt to beat several major trainers, she said, "It feels great," but also credited the team behind the horse, and added, "I'm just blessed to be here.

"[23][24] At the end of 2013, Ritvo was named as a recipient of the Lou Smith Memorial Award for Yearly Achievement, given by the New England Turf Writers Association, noting her Massachusetts roots.

[26] ESPN noted the worldwide success of women horse trainers in 2013, particularly owing to wins in three of the world's major races within a one-month period.