Generally speaking, struvite stones / crystals will form when the animal’s urine pH becomes neutral or alkaline (pH 7 or greater) and urine is concentrated. Carnivores (dogs and cats) that eat a fresh red meat based diet naturally produce acidic urine which prevents this crystal formation. The food itself has a natural water content of 60-70%, which assists in preventing dehydration and excessive concentration of urine (especially in cats).
Diets that are too high in cereal and vegetable levels will result in a more alkaline urine, which is typical of many dry foods and tinned foods. Commercial pet foods commonly contain significantly higher levels of non-meat ingredients, as red meat proteins are the most expensive ingredient used, and are generally kept to a minimum level for economic reasons – meat by-products, and white meats such as chicken, do not have the same acidifying effect as red meat.
The prescription diet your vet may suggest will primarily include artificial acidifiers, but you can achieve this naturally using Vets All Natural Complete Mix. I advise using additional vitamin C (make sure it is ascorbic acid, and not a buffered version like sodium ascorbate) and I also suggest using cranberry tablets. Cranberry does contain high levels of vitamin C, but the primary effect of cranberry is to create a mucilaginous lining on the mucosal surface of the bladder wall, which inhibits the attachment of bacteria and assists voiding of any contaminants with normal urination.
I suggest you make sure you feed primarily red meat if you are using Complete Mix (eg Kangaroo meat) but increase the meat to 70% of the diet, and make the soaked Complete Mix only 30% (by weight/volume). You can add about 1-2g of vitamin C powder per day (1/2 teaspoon) and cranberry powder. I would suggest you have your pet’s urine tested for pH every month for the next 3-4 months (or ideally do this weekly at home using a pH test strip), to make sure it is acidic. Ideal pH is about 5-6 for a dog, and 4-6 for a cat. Once the pH is stable, you can cease the cranberry supplement, then check a month later to make sure it has not changed.
By Dr Bruce Syme
Please feel free to phone the clinic for further information on how you can help your dog or cat, if they have struvite stones or crystals – 07 5449 1453