I'm sorry your kitty is experiencing this problem.
It's possible that she does have acid reflux or just excess acid in her stomach, that is causing nausea and then causing her to throw up. If she has acid reflux, the acid coming up into her throat is burning her esophagus and her throat, so that may be why she's swallowing hard when she eats. You can try to give her 1/4 tablet of a 10mg. Pepcid AC (generic is Famotidine) about 30 minutes before her breakfast and see if this helps; it should control the acid. Here is more information:
Always check with your vet before giving any over the counter medications.
Since she's hyperthyroid, it's possible that she has swelling of the thyroid or a tumor on the thyroid, and due to it's location near the throat, it could be pressing on her esophagus when she swallows, causing discomfort. Ask your vet if some imaging (x-ray, etc.) could be done, to determine if this is the case.
It also may be possible that her dosage of thyroid medication needs to be adjusted, so her levels should be checked with another thyroid blood panel.
If she no longer lays on her sides, she must be feeling pain or discomfort, so the vet can feel for any abnormalities and/or do imaging of these areas, as well.
She should be eating high quality wet food (smooth, paté food only--no chunks, shreds or slices) and no dry, because she had the teeth extracted and also, it will bother her more, when she swallows. In addition, the food she's eating now may contain allergens that are causing the throwing up. Corn, soy, wheat, gluten, artificial colors, flavors and preservatives are common allergens to cats. Some cats are also allergic to the protein source (meat/fish) in some foods. Some companies make limited ingredient diets, which contain novel proteins and carbohydrates like duck, venison, green pea, brown rice, etc. Royal Canin, Natural Balance and Blue (L.I.D), in addition to others, make these kinds of foods. Feeding a grain-free food is also healthier. Here is an article written by a feline veterinarian, about the best way to feed our cats:
I hope all will be well with your furry girl!
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