Roza, who became the first woman to top the UK charts, died aged 82 last August, leaving £992,836 in her will.
Despite the fact she loathed her best-known hit, the singer left a slice of her fortune to dog charities.
Roza was a vocalist with The Ted Heath jazz band group, in the 1950s.
Famed for her glamour, the twice-divorced singer once described her 1953 hit as "rubbish" and never sang it after the recording.
When later told it was Margaret Thatcher's favourite song, she said: "Well I suppose she had to like something."
In 2004 she told an interviewer she never wanted to record it, adding: "I sang it once, just one take, and vowed I would never sing it again. When it reached number one, there was enormous pressure to perform it but I always refused. It just wasn't my style."
Probate records show Roza left around £300,000 to 11 charities, £190,000 of which went to Battersea Dogs and Cats Home, Guide Dogs for the Blind Association and the Cinnamon Trust.
The rest of her wealth went to her friends and relatives.
After her "Doggie" hit, twice-divorced Roza of Wandsworth, South London, went on to star in cabaret and with the Ted Heath Band.
And she had other hits including Jimmy Unknown and Too Young To Go Steady.