Smokie Throwing Up - Ideas?

I have a 11 year old male cat Smokie (neutered). He was diagnosed with Hyperthyrodisim on January 21, 2011. He's been on medication 1/2 pill am and 1/2 and 1/4 pill pm. Stable. He started throwing up about every few days last april.  He wasn't loosing any weight.  Brought him in to check his thyroid and it was around 2.0. Vet thought it was due to hairballs because hew as getting some up.  It didn't seem to be bothering him.  She said I could try 1/4 tab generic pepsid to see if it would help. It did for a bit the frequency slowed down to every 7 days.  After a month I increased it to 1/2 a pill once a day.  It then spread out to once every 2 weeks and then once a month.  Now all of a sudden it's increasing again about every 4 or 5 days.  He was last in for a thyroid check in October and T4 was at 1.5 which is good and stable.  He was having dark waxy build up which vet said was due to allergies.  So I recently switched cat foods to one that is with no grain and salmon free.  I have mixed it 1/2 with old and 1/2 with new.  And started this Thursday. Yesterday he threw up twice an hour apart.

I do plan on bringing him in, but wondering what could be causing the vomiting?  I thought at first it might be the meds but pepsid wouldn't help that.  Then I thought it might be food allergy (hence switching of food) but then if it was food allergy pepsid wouldn't help that either.

I did some research and other problems that can occurr with vomiting is IBD and Pancreatitis.  But the only signs he's sowing of those two are the vomiting.  I know food allergies can result in gastrointestinal issues such as vomiting. But sometimes it's hours after he eats and others it is digested food.

I'm trying to figure out what is causing it if all his blood results as of October were normal?  Is there someone online that is knowledgeable in food allergies that I could talk to?  

I plan on calling the vet to make an appointment, however, she's not open until Tuesday.  So, I'm wondering if there is something OTC that I can give him now to help the vomiting. Maybe something anti-nausea?  Other than the vomiting he is normal playful and happy.  I just don't want to irritate his stomach with all the throwing up.

Thanks!

When changing kibble, going 1/2 and 1/2 is too much of the new food all at once  You should start slower than that, as a general rule.  1/4 new to 3/4 old, then up to 1/2 and 1/2, then up to 3/4 and 1/2, then all new.  So...it could be as simple as too much of the new food, to fast.  grain free is a different make up , so it might be richer. 

'course, I am speculating that this is even kibble.  If canned, then you don't even need to mix at all.  You should be able to go right to the new food with no mixing at all. 

Why would you think it's his meds?  Has he recently had a change in them? 

So, let me just see if I've got this straight.  You want to switch foods because he's allergic to something which is causing him to get gunk in his ears, correct?  So you switched to grain free and that is (possibly) making him throw up?  What was he eating before, and what are you switching him to?

Well the food he was switched from was also grain free and dry. I switched thinking maybe it was another ingredient in the old food making him throw up. Both are grain free just this one doesn't have salmon in it. He was on a Mounds Perfectly natural, and is going to Feldiea I think it is. He started throwing up back in April of 2012.  Originally he was throwing up a lot of hair so I thought it was just hairballs, but he's never had a problem with them so I thought it was odd. Tried hairball remmedies, nothing was working. Eventually it wasn't hairballs any longer and there was no hair in it what so ever.  so in October of 2012 I had his T4 checked to make sure it was still stable, and it was.  But I have heard that the medication, even after being on it for a while, can start irritating their system.  So I thought maybe trying some generic pepsid and at first it was like every other day. Then with the start of the pepesid at 1/4 of a tablet, it was once every 5 days.  After a few weeks then once every 7 days.  Then the vet said I could up it to 1/2 a generic pepsid. So after a week or so of that it was once every two weeks or so he'd throw up.  Then recently it's becoming about once every 5 days or so.  I've noticed the dark waxy build up in his ears. She said it was from allergies.  So I thought I'd try to change the food thinking maybe both are related to a food allergy.  The last day he's been okay no throwing up.  Not sure if maybe the pepsid is causing the increase of vomiting or what. I plan on getting him into the vet again to see what she thinks.  I just don't want to irritate his stomach so he's throwing up blood again like he did prior to being diagnosed.Other than the vomiting he's fine. He's not losing weight. He's eating and drinking water. Pooping and peeing normally.

Just wanted some other thoughts on ideas.

Thanks!

Mel

I still think it may have been switching the kibble too quickly.  When you change kibble (even grain free to grain free), you need to go slowly, as I mentioned above. 

I've never heard of Pepcid CAUSING vomiting.  When Pepcid wasn't working so much anymore for my Sven , our Vet had me give him Metoclopramide along with the Pepcid.  If Smokie was throwing up blood at one time, sounds like he may have had an Ulcer.  

Glad to hear he's better now, but I would still go slower on the food change.