Hi Laura,
SO sorry Max (and you!!!) are going through ALL of this.... .. You are certainly getting hit with a lot of different things all at once!
Regarding the ear issues and pneumonia ..... typically these are not directly EPI related.... although i do know that food allergies/sensitivities can trigger a real mess with a lot of gunk in the ears causing an infection.... so maybe this is part of the equation. Regarding the extreme hacking from acid reflux triggering pneumonia.... i have not heard of this with EPI dogs, but then again, i have learned never to say never.
So.... for now, i would like to focus on some of what i noticed in your post EPI related that you can address so that at least Max can hopefully start responding to the EPI treatment as expected.
1. You are not giving the Tylan properly... you need to give 1/8 of tsp with breakfast and then another 1/8 tsp again with dinner. ... (typically approx 12 hours apart give or take)... If Max is around 60lbs or more... then you need to be giving 1/4 of a tsp of Tylan twice a day.
2. I am confused by this statement "Royal Canin GI low fat wet food, 4 cans a day, 1.33 cans (18 oz) 3x daily" ......... If i am looking at the right product, the RC GI low fat food is 13.5 ounces per can..... if you are giving 4 cans a day... you should be giving at least approx 3 tsp of enzymes not 2 tsps of enzymes.... and if the stools are still sloppy, then you need to up the enzymes even further to 1 tsp per 1 cup of food.... with wet food we start at 1/2 to 3/4 tsp of enzymes per cup.... BUT.... in the beginning, some dogs simply need more enzymes... but then as time goes on and the dog stabilizes... many can often maintain EPI with a lesser dose of enzymes.
3. with EPI dogs in the beginning.... you need to feed approximately 150% of what the dog normally should require..... you do this until they gain back all or most of their weight. SOme EPI dogs will forever need a little more food than what another dog the same weight would require.... so .....from what i am reading you are not feeding Max enough
4. with EPI dogs..... feed small meals but more frequently... if i am reading your post correctly, you are feeing Max 3 times a day which is a good frequency.
5. is there a specific reason why your vet has Max on prescription food????? Does he have a sensitivity or other health issue? If not.... you should be able to feed him OTC food.
6. Most of these dogs, unless there is another health issue.... can eat over the counter food that is very low in fiber content (to start with) and this is where we suggest looking at grain free foods HOWEVER.... avoid commercial foods that use a lot of peas and lentils. We also suggest STARTING with a food low in fiber content like 4% or even less. The reason is because fiber can destroy the efficacy of the enzymes from anywhere between 0% to 50%.... making it appear like your dog is not responding to the enzymes. SO.... start with a low fiber food and then once you dog is delivering normal looking poos .. a normal amount of times a day (1 to 3 times).... and has been doing this for a month or so.. then try a little grain.... try some rice or try a food with rice in it.... and watch the poos.... see how much fiber your dog can handle, if any, on the enzymes.
7. that acid reflux ... could very well be a product of SID or EPI. supposedly 70% of all dogs that we think have too much acid (acid reflux) it is really not too much acid, but not enough of the right kind of acid. In any case.... we see this a lot with EPI dogs. They actually do have an issue with their secondary bile acid functionality... but more often than not, it is SID (small intestinal dysbiosis) (check out the EPI & bile acid research on this page:
https://epi4dogs.com/epi-research/ ) but we only treat if needed.
SO.... how do we treat? Typically for SID we treat with prebiotics, then pre+probiotics, and if that doesn't work then Tylan. You are already doing the Tylan. SO... You can try Slippery Elm first for acid.....(
https://epi4dogs.com/slippery-elm/) ....powder... or if that doesn't work, then try Omeprazole... talk to your vet about how much Omeprazole to give..... but there is a possibility that once you get the SID under control (via Tylan)... that this acid reflux issue may be alleviated.... but if not.... then do the slippery elm or try the omeprazole.
One thing i do want to mention... about half way thru the 45 day regimen of Tylan/twice a day.... talk to your vet about starting Max on a probiotic. either Proviable or Visbiome are the two probiotics that we are currently recommending at this time. When starting with ANY probiotic.... ALWAYS start off with less than half the recommended dose and working your way up to a full dose over the course of a week or two.
How long does it take to get stable on enzymes, etc.... it varies from one dog to the next... a few weeks to a few months.... and some (if they don't happen on the right diet, cause that is like the final piece of the puzzle... can take a real long time until you find the optimal diet for you dog!)
What other immune conditions can you expect...... either none, or some or a whole bunch. You just don't know from one dog to the next. I'd say the majority just deal with EPI..... the tougher cases are those that have to deal with EPI + IBD , with IBD being the pain in the butt. REgarding immune conditions, i would say a good portion of EPI dogs don't deal with multiple other immune situations.... but it does and can happen... you just don't know who will or will not have other health issues....................
i hope this helps a little!