Collapsing Trachea Requires Prompt Veterinary Attention 

http://www.chihuahuaclubofamerica.org/images/purina-pdfs/Purina-Collapsing-Trachea.pdf

DNA Suppressor Gene Accounts for Size Differences in Dogs 

http://www.chihuahuaclubofamerica.org/images/purina-pdfs/Purina-DNA-Suppressor-Gene.pdf

https://issuu.com/thedogmagazine/docs/thedog-magazine_issue_03-2015_chihu/32

http://www.chihuahuaclubofamerica.org/images/purina-pdfs/Purina-Differences-Between-a-Molera-and-Hydrocephalus.pdf