Ugh, ruined a good thing...

My cat eats multiple brands of wet food but only Natural Balance chicken and peas limited ingredients dry food. Periodically. I attempt to introduce a different brand as I worry about relying on one brand of dry food. Unfortunately new dry food usually leads to soft poop and I end up donating an almost full bag of food.  Yes, I do slow intros. She would return to Natural Balance without any problems.

Most recently I introduced Nature's Variety. Initially her poop was a bit soft and then after the 4th or 5th day, it became watery. I discontinued the new food and gave her only the old food-Natural Balance. The problem though was the squirts continued. So I stopped the dry food altogether and only fed wet food. Normal BMs returned instantaneously. No dry food for a week and then a week of reintroducing the old dry food in micro servings along with pumpkin.  As I increased the serving size, the BMs were a little softer but no squirts.  Today I fed her the normal amount she used to get--2 tablespoons of dry food a day.  Two incidences of watery BM came after she ate her 2 tablespoons (spread over 2 serving times).  Ugh.

Any thoughts on this?  

I'm perplexed why even her old dry food is causing her problems now?  She used to go right back to the old dry food whenever an intro to new dry food wasn't successful so this is really odd.   

My cat eats primarily wet food and as mentioned, only about 2 tablespoons of dry daily.  I keep her on some dry food because I travel.  When I travel, she gets one serving of wet food from the cat sitter and then gets about 1/2 cup of dry food from the auto feeder.  I worry about what is going to happen now if she can't tolerate any dry food at all.  My next trip is in late April so I'm getting a bit worried now.

Are there any particular ingredients in her dry food that aren't in any of the wet foods you feed?  It's possible she is developing an allergy to something in the familiar dry food, and already had an intolerance to certain ingredients in the other dry foods (you can possibly figure out which ones by comparing the old dry ingredients with the new stuff and seeing if there's ingredients that don't overlap)  How old is she?  Some cats can develop allergies or a digestive disorder over time and then only tolerate certain ingredients

She eats only grain free wet food.  The Natural Balance Chicken and Peas is technically grain free but of course it has the peas.  She and her sister have always had sensitive digestive systems.  That's why I favor the limited ingredients variety of dry food.  They did well for years on California Balance Limited Ingredients but the line was discontinued (streams of tears when I found out...).  Luckily I was able to transition them to NB.  The California Balance was Chicken and Rice and I tried other brands with similar ingredients but it all resulted in soft poop. So I stopped buying dry food with rice. Peas seems to be the go-to non meat ingredient nowadays.  Almost every brand I've tried uses it and aside from NB, they also caused soft poop.  Well, now, even the NB is causing problems.  And I tried the grain free high protein route with Nature's Variety--and that started all this diarrhea business.

I'm pretty sure there's nothing wrong with this particular bag of NB dry food as her sister is eating it and has no unusual reaction.  Usually when there is allergic or strong intolerance to a food, both girls will vomit within minutes of each other.  So I don't think it's a bad bag or anything. 

FYI, I've tried other limited ingredients dry food brands and...soft poop.  The NB was the only one that was adequate and now that's stopped working for one of my girls.  Oddly, their sensitivity issues do not extend to wet food.  As mentioned, they eat multiple brands and I can introduce a new food right away and if it's a pate type they never have problems.  Occassionally, they will get some pouch food as a treat and it does cause some softer poop and I think it's down to the ingredients needed for the gravy.

Forgot to answer question of age--she's turning 9 this summer.  Other this issue, she is in good health and is active for an indoor only cat.

Since you don't know why this is happening to her with the old food now- is having the cat sitter coming over 2x a day when you're away an option to feed wet so you don't have to feed the dry? Or having 2 different people a day come over to take turns feeding?  If that's not an option, there's always getting a timed feeder that will give up to several feedings of wet per day, but of course the cat sitter will need to refill that each day when they are there.  Has she been checked out by the vet recently? Maybe they would have an explanation and/or solution

Follow-up:

Don't know why it took me so long to think of this--find dry food that best matched California Natural's Limited Ingredients Chicken dry food. I found the recipe, copied the first 4 or 5 ingredients and googled. One of the first links to pop up was for Wysong Fundamentals Dry Dog & Cat Food at Chewy. It helped too that there was a review where a cat owner had fed CN and was looking for a substitute and that this Wysong food had worked out well. That gave me hope. It's been over a month of slowly switching my cats to Wysong and all is back to normal now. Eating dry food, no vomiting and diarrhea. Yay.

yay! i'm glad that worked out