Green Little Cat

Understanding Why Your Vet Has Prescribed Hill’s C/D

Here’s a guest post by Adrienne DeArmas. She shares her incredibly detailed research into struvite crystals and a cat’s diet. Thanks for sharing your findings Adrienne!

Struvite vs. Calcium Oxalate Crystals

Struvite crystals are usually formed in response to urine that is saturated with magnesium, ammonium and phosphorus combined with an alkaline urinary pH (not acidic enough). So, the goal of pet food manufacturers is to lower magnesium and phosphorus, thereby increasing the acid level in the urine. BUT, increasing the level too much can cause the calcium oxalate crystals so you don’t want to go too far in the other direction.

How do struvite crystals form in the first place? #1 cause is grain-based food #2 not enough moisture (dry food diet). If you are not going to feed a raw diet, get a water fountain ASAP. Or, you can always make your own out of a fish tank pump and a bowl full of rocks. The latter is harder to keep clean for some reason, never figured that out. Also, make sure you filter the chlorine from the tap water your cats drink with a Brita or similar type product. Another option: get a rain barrel and use that water (as long as the water is not coming off an asbestos roof etc). #3 and, believe it or not, STRESS.


Cat’s don’t need it if you feed a raw diet, they do if you don’t. Canned food has water, dry food does not. It is a marketing myth that dry food is good for cleaning cat’s teeth. Dry food has one purpose: a cat owner’s convenience. Cats prefer dry food to canned food like people prefer potato chips to carrots. Salt (sodium, sodium chloride) is often added to make cats thirsty, thereby encouraging water consumption.

pH: Alkaline vs. Acidic

The recommended urinary pH for cats is 6.0-6.5. Want to test your cat’s urine ph? Go to Petsmart and get a pond water test strip. I use Jungle Lab’s simply because that’s what my PetSmart carries but there are others out there. Simply dunk the strip in the urine after he pees I would imagine. Never done it but it should work.

Ignorance and Greed

Veterinarians are usually not nutritionists. They recommend prescription diets like Hill’s and Royal Canin because the manufacturers’ reps come to them and sell them on the products. Plus, veterinarians get “kickbacks” on the sale of the food.

What To Look For in a Cat Food

  1. Grain-free is best (especially avoiding any corn products)
  2. No by-products
  3. Not processed at a plant like Menu Foods or Diamond so that you can rest easy about recalls due to contamination
  4. A 4th factor, depending on your politics, is animal testing. Yep, that’s right, there are actually pet food manufacturers that keep laboratory animals for testing food and the testing they do is unbelievable. You don’t want to know how they determine how much zinc makes it into puppy’s teeth and nails after 5 weeks of a special diet… IAMS (also makes Eukanuba) is a vile company. I’ll send you references if you want, but I can’t look at the pics. Hill’s and Purina are also on the list but I will be honest – I cannot do much research on this topic – it upsets me too much. If PETA and ASPCA say they do it, that’s good enough for me.

NOTE: If your veterinarian insists on a “prescription” diet, you can tell him or her about Wysong Struvatrol or find a new vet. Struvatrol™ is designed to provide nutritional support to the urinary tract and production of acidic urine through archetypal nutritional balances, biochemically rich ingredients and non-thermal processing.

What you feed your cat is your decision. What your cat eats is ultimately his or her decision. If your child only wanted to eat candy bars, would you let them? WARNING: cats are stubborn and will not eat if they don’t like their food!! This can be life-threatening, so be prepared to try different varieties and mix them in with their current food, changing the ratio over time until they are eating good food. Switching cats from dry food to canned is often seemingly impossible. You may waste good (expensive) food to start, but just think of the vet bills you’ll save later!! is the best benzo for long term, chronic anxiety and panic disorder.

Food Comparison Chart