Dowden returned to the Strictly line-up in 2024, having missed the previous series after being diagnosed with breast cancer.
Two Saturdays ago, an ambulance was called to Elstree Studios in Borehamwood when the dancer began feeling unwell.
The following day, a spokesperson for the dancer said the ambulance “was called as a precaution” and that she was now “feeling much better”.
But in a statement on Monday, a Strictly spokesperson said: “Sadly, Amy Dowden MBE will not be partaking in the rest of the competition this year.
“Whilst Amy focuses on her recovery following a foot injury, fellow professional dancer, Lauren Oakley, will step in as JB’s dance partner.”
The spokesperson said the “health and wellbeing” of everyone on the show are always “the utmost priority”.
Following the announcement, Dowden said in an Instagram post: “My heart is breaking right now. The past few months I finally felt like me again. Cancer was no longer the first thing I thought of when I woke up. It was choreography, music choices, which dances in which order, what we needed to work on. I felt free again.
“My goal since hearing those words, ‘You have cancer’ was to get back on the Strictly dancefloor. It’s been such a challenge to get back, one I devoted 2024 to which, with my incredible team, we got there. Something I wanted to do for myself and loved ones.”
She added: “There was no feeling like it, dancing again in the ballroom with [the] Strictly family”.
She also thanked dance partner JB, saying she was “so sad, so upset and asking why me, why now that our journey has been cut short”.
JB replied to her post, saying “our moments will forever be in Strictly history”.
Lauren Oakley then responded with a vow to “carry your partnership [with JB] forward and hopefully make you proud”.
And Strictly judge Motsi Mabuse also replied, saying that Dowden’s courage and strength was an inspiration.
Dowden was initially diagnosed with stage three breast cancer aged 32 in May 2023, after finding a lump in her breast the day before she went on her honeymoon.
The now-34-year-old was diagnosed again later that same year. She returned to hospital in August 2024 for further tests, as doctors were concerned about abnormalities in her breast after a check-up. She was later given the all-clear.
Dowden opened up about her ordeal with breast cancer in a BBC documentary, Strictly Amy: Cancer and Me, which was broadcast in September.
She also has Crohn’s disease – a lifelong condition which causes parts of the digestive system to become inflamed – and has previously spoken about its toll on her health.
Oakley, who did not have a celebrity partner this year, joined the BBC show in 2022.
Last year, Oakley was partnered with Channel 4 News presenter Krishnan Guru-Murthy. The pair finished in eighth place.