Neil Patrick Harris calls late Doogie Howser, M.D. costar James B. Sikking 'one of the kindest, wisest, funniest, and most generous people' he's ever known following veteran actor's death at 90

Neil Patrick Harris paid memorial to his late Doogie Howser, M.D. costar James B. Sikking Monday, following the veteran actor's death at the age of 90 after a battle with dementia.

'Jim Sikking played my dad in Doogie Howser, MD, and was one of the kindest, wisest, funniest, and most generous people I’ve ever known,' the Albuquerque, New Mexico-born actor, 51, captioned an Instagram post featuring an image of the late actor.

Harris called Sikking - who played his character Doogie Howser's father Dr. David Howser on 97 episodes of the ABC series on Doogie Howser, M.D. from 1989-1993 - 'a true professional,' and touted his personal virtues.

'He treated everyone with respect, taught me countless lessons, yet always had a spark of mischief in his eyes,' Harris said. 'It was an absolute honor to be his son. My condolences to his actual family for their loss. #RIP.'

A number of Harris' colleagues and followers comforted him amid the time of loss, including his Uncoupled costar Emerson Brooks, who said, 'May his memory be a blessing. Condolences to his family.'

Neil Patrick Harris, 51, paid memorial to his late Doogie Howser, M.D. costar James B. Sikking Monday, following the veteran actor's death at the age of 90 after a battle with dementia. Pictured in NYC last April

Neil Patrick Harris, 51, paid memorial to his late Doogie Howser, M.D. costar James B. Sikking Monday, following the veteran actor's death at the age of 90 after a battle with dementia. Pictured in NYC last April

Harris remembered Sikking in an Instagram post featuring an image of the late actor

Harris remembered Sikking in an Instagram post featuring an image of the late actor

Brooks added that 'it’s been a rough month for us 1970s kids' amid 'losing so many legends in the wake of a spate of celebrity deaths in recent days, including Richard Simmons, Dr. Ruth Westheimer, Shelley Duvall and Shannen Doherty.

Others chimed in on the late actor's personal and professional qualities in response to Harris' post about Sikking, who passed away 'peacefully at his Los Angeles home surrounded by family,' his rep Cynthia Synder said in a statement, according to People.

'Damn!! This was just a terrible weekend,' one user said. 'I first remember him as your dad but later fell in love with him on Hill Street Blues! He was such an addition to everything. RIP.'

Another user remarked, 'LOVED that show, especially the kindness of Doogie’s mom and dad.'

Said one user: 'He was a wonderful actor and always enjoyed his talent. Obviously a genuine human. How lucky you are to have had him in your life.'

Another user said, 'I had the privilege of knowing Jim through an annual charity event that he supported. He was a lovely person, and will be missed by many.'   

Both of Sikking's most-prominent TV roles - on Doogie Howser, M.D., and prior to that, Hill Street Blues - were on shows created by late producer Steven Bochco, who died in April of 2018 following a battle with leukemia.

From 1981-1987 Sikking portrayed Lt. Howard Hunter - the head of the Emergency Action Team - on 144 episodes of the NBC police procedural series Hill Street Blues.

Sikking, Neil Patrick Harris and Belinda Montgomery pictured on Doogie Howser, M.D. in 1993

Sikking, Neil Patrick Harris and Belinda Montgomery pictured on Doogie Howser, M.D. in 1993

A number of Harris' colleagues and followers comforted him amid the time of loss, including his Uncoupled costar Emerson Brooks

A number of Harris' colleagues and followers comforted him amid the time of loss, including his Uncoupled costar Emerson Brooks

Others chimed in on Sikking's personal and professional qualities in response to Harris' post

Others chimed in on Sikking's personal and professional qualities in response to Harris' post

He garnered an Emmy nomination for Outstanding Supporting Actor in a Drama Series in 1984 for the role.

Sikking was born in 1934 in Los Angeles and an alum of El Segundo High School and UCLA, where he got a Bachelor's degree in Theatre Arts, according to the outlet.

He also served in the Army, later saying that he drew upon traits exhibited by his drill instructor for the Lt. Howard Hunter role on Hill Street Blues.

Sikking in April of 2014 said in an interview with The Fresno Bee, 'The drill instructor looked like he had steel for hair, and his uniform had so much starch in it, you knew it would sit in the corner when he took it off in the barracks.

'So when I started to play Howard, I picked out the way he should be dressed. It had to be a very military look. He had to have those jump boots. When people asked me where I got the idea for his look, I told them it was the same look I had in the Army.'

Sikking early on his career was active in plays, performing at the Barn Theatre School in Michigan, while working steadily on TV over the 1960s and 1970s.

Among the shows he appeared on in the 1960s included Perry Mason, General Hospital, My Mother the Car, The Fugitive, Bonanza and Adam-12.

In the 1970s, Sikking was seen on shows such as M*A*S*H, Hogan's Heroes, Night Gallery, Mission: Impossible, The Doris Day Show, The Streets of San Francisco, Mod Squad, Columbo, The F.B.I., Eight Is Enough, Starsky and Hutch, Charlie's Angels and The Rockford Files. 

Sikking, known for appearing on shows such as Hill Street Blues and Doogie Howser, M.D., has died at the age of 90 after a battle with dementia. Pictured in LA in 1986

Sikking, known for appearing on shows such as Hill Street Blues and Doogie Howser, M.D., has died at the age of 90 after a battle with dementia. Pictured in LA in 1986

The veteran actor was pictured at an event in Hollywood, California in January of 2011

The veteran actor was pictured at an event in Hollywood, California in January of 2011

Sikking portrayed Lt. Howard Hunter on 144 episodes of the NBC police procedural series Hill Street Blues. Pictured opposite Jan Stratton on a 1982 episode of the show

Sikking portrayed Lt. Howard Hunter on 144 episodes of the NBC police procedural series Hill Street Blues. Pictured opposite Jan Stratton on a 1982 episode of the show 

Sikking garnered an Emmy nomination for Outstanding Supporting Actor in a Drama Series for his portrayal of the head of the Emergency Action Team in 1984. Pictured in 1983

Sikking garnered an Emmy nomination for Outstanding Supporting Actor in a Drama Series for his portrayal of the head of the Emergency Action Team in 1984. Pictured in 1983

Sikking, pictured with the late Richard Roat on a 1984 episode of Hill Street Blues, which he called the 'best show I was ever on' in a 2014 interview

Sikking, pictured with the late Richard Roat on a 1984 episode of Hill Street Blues, which he called the 'best show I was ever on' in a 2014 interview 

Sikking in 1981 began with Hill Street Blues, a police show that didn't initially command large ratings, but racked up acclaim from critics, garnering eight Primetime Emmys on eight nominations in its debut year.

'When the Emmy nominations were announced, I was dumbfounded,' he told The Fresno Bee. 'I thought I was about to be unemployed and we ended up being the most-awarded show that year.'

In all, the series would claim 26 Emmy wins over 55 nominations in its seven-season run.

'I've been an actor for 50 years, and when I look back at the show, I think it was the best show I was ever on,' he told the outlet.

During his Hill Street Blues run, he also appeared in the 1984 movie Star Trek III: The Search for Spock as Captain Styles.

Other 1980s series he appeared on included the Bochco series L.A. Law, Who's the Boss? and Hunter, as well as films such as Outland, The Star Chamber and Up the Creek.

In 1990, he appeared in the Gene Hackman mystery thriller Narrow Margin with Anne Archer and late character actors J.T. Walsh and M. Emmet Walsh.

After his run on Doogie Howser, M.D., Sikking appeared in a multitude of TV shows and films throughout the rest of the decade, most notably 1993's The Pelican Brief with Denzel Washington and Julia Roberts; and on the series Brooklyn South from 1997-1998.

Sikking was remembered by a number of fans on social media amid news of his passing

Sikking was remembered by a number of fans on social media amid news of his passing 

Sikking was seen with actor Jon Tenney (L) on the CBS series Brooklyn South in 1997

Sikking was seen with actor Jon Tenney (L) on the CBS series Brooklyn South in 1997

He went on to appear on two episodes of Curb Your Enthusiasm in 2004, in the 2005 film Fever Pitch, and on the TNT series The Closer in 2012. 

Sikking was remembered by a number of fans on social media amid news of his passing.

A tweet from the account Hill Street Blues Fan Group read: 'Saddened by the passing of James B Sikking. Howard was my favourite character on the show. R.I.P.'

Another user said, 'R.I.P. James, thanks for all the memories. Hill Street Blues was a huge part of my cultural life in the 1980s. Magnificent show and Howard was a great character. So many other great roles, Outland, Narrow Margin, Star Chamber and more.'

Said one fan: 'Aw, man. Howard was one of my favorite characters on Hill Street Blues. Enjoyed Sikking's performance in OUTLAND as well. R.I.P.'

One fan called the late actor 'a favorite and a dynamic personality of roles,' adding, 'Rest In Peace.'

The veteran actor had been married to wife Florine Caplan in 1962, and had been wed to her more than six decades. According to People, he is survived by Florine, son Andrew, daughter Dr. Emily Sikking (Mallory 'Chip' Milam), and four grandchildren.