In this circumstance, the search is consensual based on the desired access to the boarding gate. When someone turns around AFTER willfully baiting the personnel responsible for maintaining the security of the gate, that amounts to "probable cause."
Also, please note that most airports in this country are ports of entry into the United States, and law enforcement personnel have always had rather wide powers of discretion in the immediate area of a port of entry.
In light of these issues, could you explain to us YOUR position on making English the official language of this nation?
In your case, I'll grant a humanitarian exemption so that it won't be necessary to deport your Biblical Beast of Burden.