Originally Posted by
jsloan
I read this as miscommunication from United. It sounds like the dog was checked all the way through to Chicago, but that it still needed to be claimed in San Francisco and re-checked like a piece of luggage would. Incidentally, I can't imagine why they wouldn't have been able to take the dog out of the carrier at that point.
Indeed, that's what
the CDC says:
The USDA/APHIS website doesn't appear to call this out specifically, but this makes intuitive sense to me, as presumably the traveler, not the airline, would be carrying the necessary paperwork (inoculations, etc.).
It sounds like all's well that ends well. I'm glad things worked out for the both of them.

Lot's of good questions about why the dog was or was not treated like a bag. My understanding is that the dog / kennel were treated like cargo, (
https://www.unitedcargo.com/) and not like a suitcase.
FWIW, they had to retrieve the dog in Chicago from United's Air Cargo facility, which is approximately 7.0 miles away from the actual ORD terminals. (The facility is practically at the airport - don't mean to imply that it's super far away. However to get there, you must drive, and the drive itself is about 7.0 miles. All that to say, picking up the dog is handled differently than picking up the suitcases.)