Cat has crystals....rx food.

My cat had a complete blockage about 6 weeks ago and he had to be cath'd and unblocked.  He has been on Hill's CD (rx) wet since.  Does he have to be on this for life?  Are there non rx foods that will do the job?  Just did a little on line searching and found these:

Pro Plan Focus/urinary tract health (sold at Petsmart)

Pro Plan adult/urinary tract health (sold at Petco)

Are there others we could try?  If he has to stay on the rx food, so be it.  My vet recommended it.  I just want some other opinions. 

Also, I have another male cat who has never had issues but I don't ever want to go through that again.  What should I feed him?  I'd rather not have him eat all the expensive rx stuff.  We're definitely not going dry anymore.  Sticking with canned.

I can just tell you my opinion and my experience is that one does not have to keep a cat on the c/d for life because of this. There are plenty of alternatives that work that are actually better quality ingredients for less cost than the "prescription" food. .
My cat also had a blockage and was on the prescription c/d . But then when he ended up with diabetes I needed to find him a food that was very low carb to help control his blood sugar. I was concerned because I was scared about him getting blocked again. but I did some research on crystals and diet, Here is a link to some of what i found plus what I wrote : https://docs.google.com/document/d/13MSNrDL22GVOaV1HMgqbljYgZOm1vgrmOCrgq44G17s/edit?pli=1

Basically it turned out that the same sort of high protein, low carb wet diet that was good for his diabetes was also good for his urinary tract. and in 6 years no problems with blockages, and no crystals observed in twice- yearly urinalyses done via cystocentesis and immediately checked.
I know of quite a few other cats with a similar history.

Basically , if you feed a cat a diet that is appropriate for their species -- high in animal protein and fat, very very low in carbohydrate, their urine pH naturally is mildly acidic as it should be which tends to prevent formation of crystals.
A diet too high in carbs makes the urine too alkaline and more likely for struvite crystals to form. But the prescription diets that add acidifiers can sometimes overdo it, and when the urine is too acidic , they can get calcium oxalate stones which aifnnot be dissolved and have to be surgically removed.

Also, feeding a diet of wet food helps keep the urinary tract flushed out so it is much less likely for things to clump together in there and cause a blockage. I even add a bit of extra warm water to the food especially for my male cats.

Here is a very good article about urinary tract health from the site of a vet who is very passionate about feline nutrition.
http://www.catinfo.org/?link=urinarytracthealth
She mentions that another thing you can do is to look for a wet food that is fairly low in phosphorus -- " - either below ~1.0-1.2% dry matter (not 'as fed'), or below ~250-300 mg/100 kcal ".
And she also has charts on that site that show the phosporus ( and other things) amounts for many kinds of canned cat food.

Hope that helped some, and hope things go well for your cat!

Thank you so much.  This was very helpful!