1) Rico, Hey Chihuahua (2007) by Harley Bonham, self-published booklet of dog photography.
2) Chihuahua Club of America Handbook (1988), often revised and reissued. It was done in two volumes in 1992 with pretty much the same cover design, issued again in 1996 in one volume, and as hardcovers instead of pamphlets in 2000 and 2005.
3) Chawhoeville (2004) by Phillis Lelux, self-published pamphlet with very badly designed cover, about chihuahuas growing up in the town of Chawhoeville.
4) Handbook for the Criminally Insane (2009) by Brian Holtz. Young adult horror novel featuring among other things a demon chihuahua who plans a human sacrifice for Halloween.