Dr Katy Williams, 35, and her son Finn were reportedly ‘covered in blood’ and were rushed to hospital for surgery after encountering the giraffe in South Africa.
The pair were only saved from the rampaging female giraffe when the woman's husband, Dr Sam Williams, intervened, The Sun reports.
The giraffe was found to have a two-month-old calf with her and may have become startled by the woman and her son, witnesses say.
The US-born woman lives and works on the Blyde Wildlife Reserve alongside her British husband.
‘The giraffe was with a calf and attacked them very seriously. They were very badly injured and Katy was doing all she could to protect Finn but the giraffe just towered over them,’ a source told the newspaper.
‘Sam was finishing his run and saw what was happening and managed to chase the giraffe off. His wife and child were covered in blood — you can imagine the trauma he felt.’
Doctors have since operated on Dr Williams at Busamed Modderfontein Private Hospital in Johannesburg.
Mother and son are both in a critical but stable condition.
It comes only months after cameraman Carlos Carvalho, 47, was killed by a giraffe in South Africa, while filming the British TV show ‘Wild at Heart’.
Giraffes can often weigh over 900kg and grow up to six metres tall.