[sugarcatmom]

Originally Posted by dbg10

(it's at least 5 years ago and I don't remember which one).

Some canned foods are better than others, so it's too bad that you don't remember the brand. It could be a clue to what's triggering the crystals. For instance, fish is a no-no for cats with UT issues since it contains histamines that can promote inflammation of the bladder/urinary tract. And some canned foods still contain too much carb content or other inappropriate ingredients that promote crystal formation.

Originally Posted by dbg10

I then agreed to try him on the prescription dry because he would eat it and was fine for several years until I introduced the high quality regular wet food again and he started having occasional bouts of crystals with blood in his urine and needing medication to clear his urinary tract.

Do you remember what the wet food was then? What medication does he take during those incidents?

Originally Posted by dbg10

I also have to find a wet food that doesn't cause an increase in his bouts of crystals as the one I'm using... Merrick... is not keeping him totally clear.

Do you know what type of crystals Sam is prone to? Struvite? Calcium Oxalate? Something else? This will help determine if there's a food that will help, or if there are supplements he should also be taking. For instance, some cats, even on a species appropriate diet, can't maintain a normal urine ph and need an acidifier added to their food to help keep it within range. When urine isn't acidic enough (consistently above 7.0), then struvite crystals tend to form. If urine is too acidic (consistently below 5.5), then calcium oxalate crystals can form. My suggestion would be to start monitoring Sam's urine ph at home, using test strips from a health food store. Ph can fluctuate throughout the day, so test at different times on different days to see what the trends are. If you need tips on getting a urine sample, let me know.

Originally Posted by dbg10

He has been eating dry food for the better part of his life and the SO has definitely made a difference in his urinary tract disease.

That's because it contains an acidifier to compensate for the tendency of cats eating high-carb kibble to have alkaline urine. It's kind of like adding anti-oxidants to cigarettes with the idea that they'll help prevent lung-cancer, when really, the solution is to stop smoking.

Originally Posted by dbg10

He also does not adjust well to new foods including refusing to eat and crying all day for food.

Not that unusual. Cats have a built-in suspicion of new foods as a defense mechanism to ingesting something toxic. This can be overcome, with patience and VERY gradual transitions (sometimes even taking several months).

Another part of the problem is that kibble is loaded with flavour enhancers in order to get your cat addicted to these poor quality foods. Pet food manufacturers make the biggest profit from dry food. They want your cat to love it so much that they don't want to eat anything else.

Originally Posted by dbg10

I know he can stand to go without food as he is fat but he takes it into several days without food and that is also not healthy for him.

Definitely not healthy. Quite dangerous, in fact. There are better and easier ways to switch foods, some tips which you can find here: http://www.catinfo.org/docs/Tips%20f...%201-14-11.pdf

Also watch these excellent videos by a vet for suggestions on how to convert kibble addicts:
http://www.youtube.com/watch?v=uZv0P...embedded#at=28
http://www.youtube.com/watch?v=8NWXk...embedded#at=32

You can also use the kibble addiction to your advantage. By pulverizing it and sprinkling it on top of canned food, you can entice Sam into trying new foods. Once he gets used to the different smell and texture, you can decrease the amount of powdered dry on top.

Originally Posted by dbg10

I have tried giving him fish straight out of the can and he doesn't like the taste of it.

Smart boy. I'd stay far away from fish.

Originally Posted by dbg10

So again I ask is there a high quality dry food that might be somewhat comparable to his Royal Canin SO

There really is no such thing. For one, "high quality" and "dry food" are oxymorons. Instead of trying to find something else for the interim, I would just convert Sam over to wet food using the SO until you can eventually eliminate it.

Originally Posted by dbg10

and a high quality wet food that is also recommended for cats with urinary crystals. I can find several in a google search but I wanted to know if anyone has experience with them.

Any meat-based, fish-free, grain-free wet food with muscle meat instead of by-products would be a good choice. Adding extra water to the food is also recommended. You want to flush out those crystals if they do form. Monitoring urine ph and adding a measured amount of an acidifier (L-methionine for example) if needed will also help.