Well a lot has gone on since I late updated. I'll try to keep it short. I began to see a pattern with an intolerance for certain foods (I suspect carrageenan, but there is also two foods without carrageenan that she will bring back up, those two have spinach)
So, as much as I believe in feeding cats a wide variety for both safety and to be sure of balanced nutrition, this cat cannot tolerate variety.
I narrowed it down to one food. Luckily this is a food with a phosphurous/magensium percentage very close to the Prescription c/d, so that is one less worry on my mind. The food contains no carrageenan, no spinach and nothing else on my "bad" list, with the exception of a menadione bisulfate additiive (synthetic vitamin K) but it is the very last ingredient on the list, so I will have to live with it.
The food is By Nature Organic Turkey and Chicken. Made in USA with only USA sourced ingredients. So, maybe we're getting somewhere.
So her routine was:
One food, and one food only.
Pepcid every morning with her first meal (after a 9 hour fast).
Proviable (for digestive health) and cosequin (for bladder health) mixed into a later in the day meal. (Still playing with which meal is best for the probiotic)
1 tablespoon of pumpkin a day for constipation and hair balls (now given in only two meals, but it took a long time to get to that point, had to start the pumpkin with minute amounts in every meal, but she now accepts it in half tablespoon amounts twice a day).
I stopped giving the hair ball remedies as these seemed to make the regurgitation worse.
On the above regimen, she was still regurgitating every three days. I find this unacceptable. Looking closely for a pattern, I found that she skips a bowel movement every three days. In spite of the pumpkin, she is still having trouble pooping. So, I had added in mineral oil. It took a while to work out the proper schedule for mineral oil. At first, she would have a BM an hour after getting the dose. But then, even after one dose, she still wouldn't go, so I had to dose her two days in a row. So now, mineral oil is going to be every three days, two days in a row.
I also think that these regurgitation may sometimes simply be a burp coming up. If she could only learn to let the burp up, instead of fighting it and causing herself to bring it all up instead of just the air.
Today will be day 4, without a regurgitation, if we can get through it. She just had a poop, 24 hours after the last one. It was pretty big, unusually so, for a cat who went only 24 hours ago...which also concerns me. I fear megacolon, and if I see many more of that size, I am going to have to get her in for a bowel x ray.