1) All About the Chihuahua (1976) by Mona Huxham.

2) Your Chihuahua (1966) by Ruth L. Murray.

3) Terribly plain cover for Flossygirl (2008) by Denise Melvin,
minimalist self-published booklet about
a lonely chihuahua who gets a new family.

4) Illustration page from Chihuahuas (1922) by Walter Johnson. Extravagantly rare in its first edition, it was first book devoted entirely to the subject of the chihuahua, but it's card-cover had nothing printed on it but the title. A 1980 facsimile reprint exists, itself now rare. The illustration plate depicts El Chuzon, a merle or brindle chihuahua sold by Alameda Kennels to M. R. Muller.