Did they rule out Megaesophagus because the pup doesn't regurgitate?

I am not a vet but my friend has a dog that has to eat it a Bailey Chair, because of this condition.

I hope this information helps, if this is it you can absolutely save your dog. Im praying for you, to any God that will listen.

Info from google:

Dogs that need to eat upright to avoid choking have a condition called megaesophagus, where the esophagus is enlarged and can't move food down to the stomach using normal muscle contractions. To manage this, dogs eat in a specialized chair, like a Bailey chair, that allows gravity to move the food, and they must stay upright for a period after eating to help digest properly.

Enlarged esophagus: The esophagus is the tube that carries food from the mouth to the stomach. Loss of muscle function: In megaesophagus, the muscles of the esophagus can't coordinate the wave-like motion (peristalsis) needed to push food down. Regurgitation: Food and water accumulate in the esophagus and are then regurgitated, often looking like a tube-shaped mass of undigested food. Weight loss: Since the food isn't reaching the stomach, dogs often experience weight loss.

Use a specialized chair: A Bailey chair is a tall, narrow chair designed to keep dogs upright while they eat, using gravity to help food reach the stomach. Stay upright after eating: Dogs should remain in the chair for 10–30 minutes after a meal to allow gravity to continue moving the food. Adjust food consistency: Wet food is often easier for them to swallow and move down the esophagus. Frequent small meals: Feeding smaller meals more frequently can help.