The striker slotted the ball past Asmir Begovic but collided with the keeper and stayed down before hobbling back to the dressing room.
It was Pochettino's 150th league win but it was a rare defeat for his counterpart Howe, whose side had been beaten just one in their past 10 league fixtures - only Tottenham lost fewer games in that period.
"We are concerned because still we can't know what will happen to him", Pochettino told reporters.
"Of course I worry about him, his ankle we hope it is not a massive issue for him and the team and hope he can recover as soon as possible and be available".
Dele Alli found a reply for Mauricio Pochettino's troops in the 36th minute by turning home Serge Aurier's impressive cross from the right flank.
Kane spent almost two months out between September and November 2016 with an injury to that right ankle before another two-and-a-half-week period out with the same issue between March and April 2017. "He helped the team achieve three points".
And Ivory Coast full-back Aurier completed the scoring, heading in a rebound from close range after goalkeeper Begovic had tipped away a cross from Spurs substitute Kieran Trippier.
Heung-Min Son eventually gave Pochettino's men a 2-1 lead in the 62nd minute, netting his 17th goal of the season with a volley at the far post. "We took only 18 games to get nine clean sheets at the start of the season and since then we've had to wait 11 games which is sometimes frustrating". "A winning mentality is the most important".