Hi Pat,
It sounds like acid reflux, what was he eating?? its either too high in fat, high carbs or high in oils or tooo high in Kcals per cup??
Take it back to pet shop & say he wont eat it, get refund or change for something else..
Is it dry or wet can food when the licking gulping happens ??
If it’s dry have a look at “Wellness Simple”
I feed the Wellness Simple Turkey & Potato formula, Patch get bad acid reflux when he eats a fish kibble, Id say the omega oils are too high.
https://www.wellnesspetfood.com/natural-dog-food/product-catalog/simple-limited-ingredient-turkey-potato-recipe
Boil Sweet Potato pieces instead of the boiled rice, sweet potato is excellent for stomach & bowel problems, boil rice ferments in stomach..Sweet potato freezes & thaws really good..
Start adding 1-2 spoons of tin Salmon in spring water to his cook meals, so he’s getting his omega 3 for skin, coat, brain, heart & joints..
Salmon isnt as greezy as sardines..
Baths twice a week to wash off Allergens off skin & paws..
When this happens give an acid reducer – Zantac or Pepcid google dose
or make some Slippery Elm Slurry..
Buy Slippery Elm Powder add 1/2 a teaspoon power to a cup, boil the jug, slowly add the boiling water & stir quickly till you have a thick slurry but not too thick it needs to be able to be pulled up into a syringe when cool give 4ml put syringe side of his back teeth so he swollows it, this will soothe his esophagus & stomach helps with nausea & acid reflux & sloppy poo diarrhea..
