Advise needed! Longtime vomiting, multiple cats

Hello, I presently have 3 cats. All 3 have been vomiting at least weekly for over a year. The background is as follows: - I have had cats my entire life. I recognize a cat may vomit once or twice a month without it being a health issue. The vomiting here is excessive. - The issue is not fur balls. Two of the cats are short hair and one is medium hair. I have had longhair cats who have experienced fur ball vomiting. There is no hair or hairballs in the vomit. - The cats are aged 15, 11 and 3. The 15 and 11 year old are mother/daughter. The 3rd old is an unrelated male cat. - The cats are 100% indoors. The older female cats did occasionally go outside in their youth but neither has been outside in 8+ years. - They are fed both wet and dry food. I tried discontinuing the wet food for a solid month, no change. - The dry food was originally Kirkland brand from Costco. After the vomiting began, I switched to a few different brands and ultimately settled on Iams Proactive Health Sensitive Digestion & Skin Turkey Dry Cat Food. Changing brands of dry or wet food never resulted in any change. - I tried numerous brands of wet food. The cats are very finnicky and strongly prefer Fancy Feast Flaked: chicken, tuna and trout flavors. I tried various higher quality foods ranging from fresh food from a boutique store, to blue buffalo and more. No change. - I tried changing the dry cat food bowl from a traditional bowl to a tilted bowl which advertised that was a more natural way for cats to eat with their spine aligned. No change. - I ultimately settled on a bowl with protrusions which cause the cats to pull the food out with their paws or otherwise eat much slower.  No change. - I switched the wet food from being served on a flat plate to Lickimats which have protrusions and force cats to eat slower and lick more. - The vomit varies greatly. Sometimes it is appears like the undigested food they recently ate. At other times, it is clear liquid. Sometimes it is yellow or greenish liquid. Other times it appears more like a single piece of stool in dark liquid. - I switched the water bowls from regular bowls to automatic water fountains with filters. I change the filters every 7 - 10 days. - I am VERY careful when cleaning to ensure no chemicals are used near the cat food or water. - The litter boxes are all Breeze systems and cleaned weekly. The cats otherwise appear healthy. The sole issue is excessive vomiting and I have tried everything I can think of to control it. Prior to having these cats, I had a single cat where I spent $7,000 on her in the last year of her life. I cannot afford to go through that again, for 3 cats. I am hoping for advice on something I can try, or if necessary, I can take 1 cat to the vet for testing / diagnosis if necessary.

Hello!  There was a time when old vets might have told you that the occasional bout of vomiting can be normal, but as we have learned more about cats, vomiting is largely considered a sign of pathology.  It sounds as though this may be too frequent to ignore as 'one if those things' and must be difficult to contend with at home.  Beyond taking simple measures like worming them with a proper veterinary wormer (no point using a cheap one that may or may not kill the worms, as it leaves you no further on - speak to the nurse), your cats really need to see a vet to get this diagnosed.  I can see that you have tried a lot to rule out dietary causes, and some of these - such as trying to slow the eating down - are good practice in any case.   This leaves me with three possibilities: 1) that you are not trying these foods for long enough for the cat to have time to adjust 2) that you are swapping one poor food for another (I don't know the foods you mention and have not researched them) or 3) - and quite possibly - it is simply not a dietary issue, or else it's a dietary issue that is complex than that.   Pancreatitis is a biggy that can sometimes fall into that category.  Stress may be implicated.  However liver disease, kidney disease, diabetes, cancers, hyperthyroidism, may also all be on the list. You say that you can take one cat for testing - that would only be useful if  all three cats had the same issue.  However, they are different ages and so on, so this may not be the case - we would advise getting all three checked.  It probably sounds obvious, but there is no magic test or blood test that flashes up the answer as to what is wrong with a cat - often diagnosis is a process of eliminating the most likely thing (and tests are one tool to help with this).  It helps to think through the history for each individual cat beforehand - for each separate cat, when did you first notice them vomitting?  How often are they doing it?  Where and when are they doing it?  How old (you've told me this)?  Do they hunt?  How are they in themselves?  How much is each cat drinking, roughly?  When were they wormed / what with?  What are their activity levels?  Having this written out for each cat can save valuable consulting time (therefore money) and may give your vet some early clues as to what's going on / which cat most needs your resources.   Always ask about money from the outset and never be ashamed about it - this way your vet can spend what money there is in the most helpful way. Reducing stressors in the household, such as ensuring that each cat has their own separate territory / place to hide and can get away from you and the others, costs nothing but please don't waste time on this - if one of them has diabetes or kidney disease for example, they may need your help now. Best of luck and please let me know how you get on.

Ps Have you seen our blog?  There are articles about 'tests' and about vomitting that you might find helpful.