The showbiz patriarch - whose children include Janet Jackson and the late Michael Jackson - was admitted to Albert Einstein Hospital in Sao Paulo, Brazil, yesterday (26.07.15) after feeling dizzy and losing his vision, TMZ reports.

Joe is believed to be still undergoing tests and his family are trying to decide whether to have him flown back to the U.S. for further treatment.

It is unclear as yet whether his loss of vision is only temporary.

If the music manager - who also suffers from diabetes - has suffered a stroke, it is his fourth.

He previously suffered a mild stroke in November 2012, and was placed under observation at a Las Vegas hospital after complaining of pains in his head and difficulty standing.

Hours before his medical emergency, 49-year-old Janet posted a birthday message to her dad on her Twitter page.

She wrote: ''Wishing my Father, @Joe5Jackson a Happy Birthday.

''I want to tell the world, I love and honor you.''

Joe's children have previously spoken out about their ''abusive'' upbringing, but their father insists he is ''glad'' he was a ''tough'' parent.

He previously said: ''I'm glad I was tough, because look what I came out with. I came out with some kids that everybody loved all over the world. And they treated everybody right.

''There's no such thing as beating a kid. You whip them or punish them over something they did and they will remember that.''