“It’s tough to say†accurately what causes pets to die during or immediately after flights, as each box is different, pronounced Inga Fricke, executive of pet influence programs during The Humane Society of a United States. There is, however, a aloft altogether risk for brachycephalic breeds like bulldogs and pugs, whose “short nasal passages leave them generally exposed to oxygen damage and feverishness stroke,†she said.
Article source: http://www.huffingtonpost.com/entry/flying-with-pets_us_5900e7dee4b0af6d718af002?section=us_travel