dog nutrition and oxalate

Question
My mini schnauzer (12 yrs old) had oxalate bladder stones a couple years ago and since has been on Hills Science Diet U/D.  I mix it with water to increase his fluids, and he'll tolerate it, but I'm having a couple issues with it and don't know if I should attempt to find another brand. First,, since he began this diet, his skin has become dry and flaky.  Second, it seems since the diet change he has constant problems with anal gland impaction (even had an infection once). Just last week the vet suggested we add metamucil or bran cereal to his diet.  Also, if I split his feedings in 1/2 (once in the morning and at night) the food swells in him to the point he becomes miserable, panting, and shaking.  So, I feed him in 4 smaller increments.  
I'm concerned he isn't getting enough nutrition for his skin and I'm very concerned why he keeps having thick secretions from his anal gland.  Do I search and ask vet to try to change his food to another RX brand?  Add the fiber to his current diet and also add flax seed oil for his skin? Help!

Answer
Hi Amanda,

I can certainly sympathize with your concern about this situation. It's a familiar scenario; the Hill's diet controls the condition, but is less than optimal for the dog overall, nutritionally speaking. My absolute top recomendation for a senior MS with this condition is a home made diet. Please let me know if that would be of interest for you. I'm not comfortable recommending a generic diet nor do I think it's wise to use a commercial food that is not designed with urolith control in mind. I can help you with a home made diet but first, let me know if  this is an option for you.

All the best, Catherine