two cats suddenly rejecting food

Question
QUESTION: Our two older female cats were switched from dry food to wet food because I read all your material.  They have been happily eating chicken and turkey Trader Joe's food for close to three months.  Starting about a week ago they virtually stopped eating it.  I've tried several flavors of Wellness and Natural Balance.  EVENTUALLY they will eat some of any of the four but it takes way too long, they're not eating enough, and now they're throwing up so much of it that I doubt they're getting sufficient calories.  They are otherwise behaving normally.  One is a Persian, one a Burmese.  I'm taking both to the vet I hope tomorrow but am questioning the whole thing because why would both of them be reacting in the same way?  The Persian does, I just discovered, have a nearly ingrown claw and must not be enjoying that at all, but it is not warm or otherwise appearing infected or the source of any fever (although I should have seen it coming since I've been fighting her to trim that claw for months!).  They are both very shy and spend most of their time on thte third floor of our house where our dog can't go.  He's not trustworthy with them as yet (a rescue), so their interaction with us has decreased since late August when the dog arrived, but they have always been pretty much that way and spent most of their time on the third floor anyway.  I'm worried sick myself.  Should add that up until now was extremely pleased with the results of the food switch--more energy, weight better (Burmese had been getting overweight, just all around better.  And there was no problem initially transitioning thtem.

ANSWER: Hi Jill,

I apologize for taking so long to reply to your message.  The holidays had me away from the computer for quite a while.

This is the first that I've heard of two cats, both in the same house, who have both been eating the food just quit eating it like that and at the same time.  If it was a single cat, I would worry that it was an underlying health problem, etc.  However, with both cats at the same time I'd be more likely to think that it's some type of environmental factor...maybe something has changed in your house?  You did mention that they are both very shy, thus I'd think it could be quite likely for them to get upset at the least little change and want to go off their food.  I'm not familiar with the Trader Joe's food at all...is it organic and by-product free?  Can you tell me anything about it?  How are the cats now?  Has a vet checked them out for dental problems, etc?  Please update me and if they are still being picky with their food I can try and offer some suggestions.

Sincerely,
KC

---------- FOLLOW-UP ----------

QUESTION: Thanks so much, KC.  Since my email, both have been to the vet (turned out to be just this last Friday, January 2), Susie (the 11-1/2 year old Burmese) for her full yearly exam, and Amy (Persian/Himalayan, will be 14 April 29) to check her weight and teeth.  Both passed with no problems, although there was no bloodwork or anything like that involved.  Their weights were exactly the same as a year ago (which is great especially for Susie because she was the one packing on pounds with the dry food).  Of course this not eating thing hadn't been going on too long.  As far as change and trauma are concerned, Sam the dog has unfortunately gotten access to chase and catch each cat just once, but with Amy it was weeks and weeks ago and with Susie just Friday night.  Neither was injured in any way, just scared stiff, but neither incident seems to coincide with eating problems.  In fact, over the weekend, they both resumed eating at a signficantly improved pace, albeit not enough.  Then yesterday they both are back at very, very little food.  I'll keep racking my brain for environmental factors.  As I mentioned earlier, the fact that so far we haven't trained Sam to be safe with cats and thus they are somewhat more isolated is not ideal, but the change is so minimal from the way they lived day to day anyway that I'm doubtful as to cause.  If it were summer, I'd be more concerned, but we keep our house very cool, so in winter they have always spent 90% of their time on the much toastier third floor.  They did use to spend some time in my husband's home office, where he kept the heat more turned up, but he's virtually retired now, so he doesn't spend the same kind of time there or maintain the temperature at the same level.  We bought a new pet gate that enables them to come to the second floor safely if they would like, but they aren't super inclined to do so.  They used to eat on the second floor, so we tried moving their food back there, with no success.  Our motivation was more to get them out and about and with more exercise.  Come to think of it, that food moving may have started the cycle, but I can't be sure.  It's back on the third floor, the place where they were initially gobbling it up happily, and it hasn't solved the problem.
I've changed one of their litter boxes to clumping--a new kind of clumping because they've always hated all the others I've tried and we've had to stick with the old fashioned kind.  They LOVE the new litter and won't use the old type anymore.  Timing of that is close to when they backed off eating, but they have access to both kinds of litter, so how could that be the reason?
I chose Trader Joe's food because it was listed by Dr. Lisa Pierson on line as acceptable and it's quite affordable and up till now they liked it.  So far they still don't like any of the flavors of Wellness or Natural Pride I got them.  We switched them from Science Diet Senior.  I felt bad about feeding them that food, even before I realized that wet is preferred no matter what, but for a number of years before they ate Innova dry.  While we were on vacation the summer before last, Amy got trapped by falling down a cold air vent.  It's not worth going into how this could happen when we had cat sitting in place, but suffice it to say that it's nearly a miracle she's alive today.  It took quite awhile to get her stabilized and out of the danger zone.  Her digestive system was never quite the same afterwards, and she could no longer tolerate the Innova food or any of the other extra premium boutique type dry foods we tried.  The Science Diet Senior did seem to (a) appeal to them and (b) work for her.  As mentioned, Susie started to pork up on it, however, and that's when I finally did some research.  Does this help?  I am so grateful to have you as a resource.  Thanks very much!

Answer
I'm very glad to hear that their vet appointment went well.  The only suggestions that I can offer, right off hand, are to increase the temperature in the room where they are staying and start working with the dog.  I would leave the temperature, at very lowest in the mid 60's.  If you increase the temp to the upper 60's to 70's you should notice an increase in their activity level which could very well cause them to eat more.  Also, you need to start training the dog to not chase the cats.  A dog who lives in the same house with cats should not, by any means, be allowed to bark at them, chase them, growl at them, etc.  If you need help with any of this, respond to this with your e-mail address and I will e-mail you.  I train, breed, show, and compete and will be more than happy to answer any dog training questions that you have.