Bob Newhart, who said he's known Tim Conway for "many years," tweeted early Tuesday morning that he and his wife, Ginnie Newhart, 77, are confident in the quality of their friend's care — which is being questioned by the 84-year-old's daughter
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In the wake of news that Tim Conway is suffering from dementia, the veteran actor’s famous friends are speaking out about his health.

Bob Newhart, who said he’s known Tim for “many years,” tweeted early Tuesday morning that he and his wife, Ginnie Newhart, 77, are confident in the quality of their friend’s care — which is being questioned by the 84-year-old’s daughter.

“To the many fans and friends of Tim Conway,” the actor, 88, wrote. “We have been friends with Charlene and Tim for many years and want to assure you that he is receiving the most devoted care. Sincerely, Ginnie and Bob Newhart.”

According to documents obtained by PEOPLE and first reported by The Blast, Tim’s daughter, Kelly Conway, is asking to be appointed as her father’s conservator. Kelly wishes to be in charge of the Carol Burnett Show star’s medical treatments.

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Kelly, 56, filed the documents in Los Angeles on Friday, claiming Tim’s wife Charlene is “planning to move him out of the excellent skilled nursing facility he is currently at” and place him in one that won’t give him access to “registered nurses at all times and his 24-hour caregiver and speech therapist (to help with swallowing).”

Charlene is Tim’s second wife. He was previously married to Kelly’s mother, Mary Anne Dalton, from 1961-78. (In addition to Kelly, they share daughter Jackie and sons Jaime, Tim Jr., Pat, Corey and Shawn.) Neither Charlene or Kelly responded to PEOPLE’s requests for comment.

Kelly also stated that Tim cannot “properly provide for his personal needs for physical health, food, and clothing” and is “almost entirely unresponsive.”

She hopes to be granted guardianship so she can also administer her father’s medications herself.

Tim starred on McHale’s Navy, costarred in the 1970s comedy The Carol Burnett Show, provided the voice of Barnacle Boy on Spongebob Squarepants and even made a special appearance on the second season of 30 Rock, which he received an Emmy for.