I sat in the bulkhead recently from MSP to SFO. I was seated in 7D, and the passengers in 7B and 7C (across the aisle from me) had a dog. It wore a guide dog vest, and the dog was well-behaved and kept to itself (didn't even look around the cabin or at other passengers) during boarding.

This changed one hour into the flight.

The dog started pooping as the cart was going through coach for the snack and drink service. The flight attendants worked together to bring paper towels, fistfuls of the alcohol wipes and empty bags, and the flight attendant who was working in first class came by to dump two bags of coffee grounds on the carpet to try to get rid of the smell. The dog-owners tidied a bit, but only picked up the bigger chunks to bring to the lavatory. They left some behind.

The flight was nearly full, but the passenger in 7A was offered a seat change to the exit row (one of only two empty seats onboard), which he took immediately.

A half hour later, the dog started pooping again. Out came more paper towels, plastic bags and coffee grounds from the flight attendants. The passengers, again, cleaned up only the big bits, leaving some more poop behind.

The dog then pooped two more times before we landed.

When we landed at SFO, the carpet in front of seats 7A, 7B and 7C was a rich brown from the mix of left-behind poop and coffee grounds. (I won't post the photo I sent my brother.) The passengers in 7B and 7C left the plane as if nothing happened and left behind the multiple bags of paper towels and poop. No one (not even the crew!) told the cleaning staff what was waiting for them in row 7. I got off the plane as fast as I could because the smell was awful and told the cleaning staff waiting outside the door that there was poop in row 7 and that she should tell her manager that it was really unsanitary.

What would you do in this situation? Should I have told the gate agent at the counter that maybe the next flight should have a different plane? I assumed that the flight attendants who were aware of the poop in-flight (they brought paper towels and wipes many times, after all) filed a report when we landed? Did they maybe chat with the SFO staff when we were in-flight?