It does sound like a food allergy or sensitivity. The trick is figuring out what is causing the problem.
I have a little scarf n barf cat... went through several foods both wet and dry with him and various techniques to get him to slow down and KEEP his nourishment IN his belly.
Not sure WHICH of these things did the trick, but I feed:
- Taste of the Wild dry
- Mostly Authority and Nutro Wet (Tex is not fussy and will eat most anything)
- I put his WET food in a "speed bump" bowl. Dogit "Slow it down" I think it's called.
NO puking for over two months.
I also suspect a bit of a fish sensitivity so I watch how much fishy wet I give. TOTW is a mixed protein dry - has fish it it. Sometimes I mix in a little BG Chicken dry. The boys seem to like that, too. It also goes in their treat ball.
I have used the By Nature. I think it is pricey. Brandon Farms at Kroger is the same for about 20cents a can less. It is kind of dry and gummy... so if I use it I mix it with something more juicy and/or I add a little water.
Also note that switching over completely to grain free wet might be too rich for your cats. Might have to mix in something else. Authority wet is not bad - decent food.
My boys unformly HATED the NB duck and green pea wet... so to each cat its preference.
Sigghhh.... I also tried Cal Naturals, too. Nope. Nuh-uh. Zip.
Not that this is right for your cats, but the fave of the moment around here is half Nutro chicken or turkey and half Authority ocean fish formula. Very nearly the clean plate club combination.