older dogs/bladder crystals

Question
I have a Lakeland Terrier who will be 14 in two weeks.  Since she was 5 months old, she has been on Science Diet C/D because of her propensity to develop bladder crystals.  A couple of months ago, she became very sick because of intestinal impaction.  We got this cleared up but were told to keep her on W/D for fiber.  Since then, she has developed urinary problems again, with a very concentrated, thick urine and high frequency of urination.  She probably has bladder crystals because of the diet.  This seems to be a "catch 22" situation with her.  Without fiber, she gets impacted.  With fiber, she gets the urinary infection.  What do you suggest I feed her to avoid both problems?  Today, I began with a combination of S/D and tuna in water.  Is this a good alternative?  Thank you for a quick response.

Answer
Science Diet is never a good alternative. Try a good grain free premium quality dog food, I like Flint River, Wellness Natural Balance, Oriijen. Try staying away from high protein foods but you want good protein sources. You can actually give your dog fiber capsules, just like humans, or add powdered fiber to her food.
Make sure she gets plenty of exercise and lots of liquids. Add some veggies to her diet. carrots. green beans,. broccoli,canned pumpkin for added fiber, sweet potatoes,spinach, kale.
Good luck
Cindi