Despite his profound health challenges, Cowsill continued to write, perform and record. He retrained himself to sing, to accommodate losing the use of one lung. Six months before his death, he accepted an invitation to perform two songs onstage with Calgary honky-tonk singer-songwriter Tom Phillips. His last recording was "The Days I'm With The Horses", recorded in Calgary on July 18, 2005. The song, written and performed by Stewart MacDougall, was produced by Cowsill, who also sings background vocals. It is included on "Rivers and Rails: A Tribute to Alberta", a compilation album by various artists, released in 2007. The album had originally been planned as a 2005 release, to coincide with celebrations of Alberta's centennial. Cowsill also co-wrote, with Ralph Boyd Johnson and Suzanne Leacock, the title song to the album, on which he plays guitar.