Howe's daughter Cathy said Tuesday night the 86-year-old Detroit Red Wings legend had lost much use of his right arm and right leg. Howe suffered the stroke in Lubbock, where his daughter lives.
"We'll just see what each day brings," she said. "He's tough. He's not giving up."
Howe's daughter said his speech is slurred, but he's been looking at family pictures and pictures from his playing days, and he's able to recognize and identify people he played with. His three sons were on the way there to see him.
"The stroke kind of came out of nowhere," said his son Dr. Murray Howe, a radiologist.
The man known as "Mr. Hockey" set NHL marks with 801 goals and 1,850 points — mostly with the Red Wings — that held up until Wayne Gretzky surpassed him in the record book. He was revered for his blend of finesse and grit, playing 26 years in the NHL until he retired for good from the league at age 52.
With one shift for the Detroit Vipers in the International Hockey League in 1997, he played professionally in a sixth decade at the age of 69.
"Wishing my friend Gordie Howe all the best, you're in all of our thoughts and prayers," said Prime Minister Stephen Harper in a tweet from his verified account.
Murray Howe said last year his father was still strong but was struggling a bit with short-term memory loss. The senior Howe also suffers from a form of dementia. This year, around the end of August, he underwent a procedure to help with back trouble. That operation helped significantly.
"He ended up getting what's called a minimally invasive lumbar decompression," Murray Howe said. "He was doing great for a while."
Howe's daughter said his spirits were still strong after the stroke.
"He's as tough now as he was when he played," she said.
Howe played 25 seasons with Detroit, winning four Stanley Cups, six Hart Trophies as the NHL's most valuable player and six Art Ross Trophies as the league's leading scorer.
He debuted with the Red Wings in 1946 at the age of 18 and quickly became a leader on the team. Howe and teammates Sid Abel and Ted Lindsay became known as the Production Line thanks to their hard-nosed style of play.
The term Gordie Howe hat trick — when a player scores a goal, records an assist and gets in a fight in one game — is named after him.
After a brief retirement in 1971, Howe returned to the ice as a member of the World Hockey Association's Houston Aeros, joining his sons Mark and Marty.
In 1977, the three Howes moved to the WHA's New England Whalers. When the league folded in 1979 the newly named Hartford Whalers joined the NHL with the Howes in tow.
At 51 years old, Howe played all 80 games of the 1979-80 NHL season with the Whalers, helping them to the playoffs with 15 goals.
Howe's longevity and scoring touch made him one of the most productive players in hockey history.
In addition to his 1,850 points in the NHL, Howe also had 174 goals and 334 assists in 419 WHA games. Add it all up and in 2,275 games he scored 975 goals, assisted on 1,383, and amassed 2,358 points.
With files from The Canadian Press