Mega Esophagus.
The esophagus is enlarged due to genetics or illness, and food doesn’t move into the stomach correctly. A lot of dogs grow out of the condition if born with it but Zenya did not.
She eats upright in a Bailey Chair to help move the food into the stomach, and adding sildenafil before eating is helpful also.
She will have a shorter life ( 5-7 years) and she’s almost 5. She’s had a great life and fulfilled ours.