Some game developers were so intrigued by dogs playing poker that they included versions of his paintings into their video games as Easter eggs.
I am proud to say I have never played EverQuest, so I will have to believe another web site which states:
I do not have a Dreamcast, so once again I will have to take someone else's word on this reference:

Simply pop your MDK2 disc into a CD-ROM drive and do a directory search for a folder titled "MDK2". Inside you'll discover a wealth of development information on the game as well as a few laughs.
Among the items to be discovered are MDK2 pictures and developmental artwork as well as sound samples and outtakes. For anyone who's been in a 1970's (or Heaven forbid, in the last decade) rec room, you may be familiar with dogs playing poker by Cassius Coolidge.
Perhaps the second most tacky painting behind a velvet Elvis, Bioware has paid homage with their own version of the popular portrait. In it, Kurt, Max and the diggy-Doc join in with the pooches for a few hands.