Michelle, I've had vets recommend vit c to cats to prevent crystals(struvite) after urinalysis. This would be after confirming there was no bacterial infection. Vit c acidifies the urine which helps with struvite crystals, its the calcium oxalate buggers that will get you but there are more factors than just vit c.
I know generic and human forms of vit c and ester C contain calcium, which is the main concern when looking into calcium oxalate crystals. Suppliments given need to be tailored to the individual animal based on what they are fed and what is going on at the time. The calcium content is also what makes me only consider Prevention. I have to do more looking into it.
The magnesium, phosphorous/phosphates, calcium, and ash levels need to be watched, most especially if you give suppliments.
Crystals:
(
http://www.veterinarypartner.com/Content.plx?P=A&A=1741 )
"In older times (20 years or so ago), cats virtually never developed calcium oxalate bladder stones. Cat bladder stones could reliably be assumed to be made of struvite (a matrix of ammonium-magnesium-phosphate). In those days, feline lower urinary tract symptoms were generally caused by struvite crystals in urine (or at least this was the assumption). Also in those days, feline lower urinary tract symptoms were extremely common.
The pet food industry responded by acidifying cat foods to prevent the development of crystals. In a way it worked. Feline lower urinary tract symptoms declined. Male cats with struvite urinary blockages became far less common. The trade off was that calcium oxalate bladder stones began to develop. Acidifying the body leads to an acid urine pH and more calcium loss into the urine, both factors in the development of a calcium oxalate stone. Currently most bladder stones formed by cats are calcium oxalate stones."
and for dogs:
(
http://www.b-naturals.com/newsletter/bladder-stones-crystals/ )
"Alkaline pH and struvite crystals are not caused by a diet of alkaline foods; they are usually caused by bladder infections. Therefore, trying to make the urine more acidic will not get rid of the infection. Alkaline pH can also be normal, as pH can vary a great deal even in the same dog at different times of the day, and also by the way the urine was captured and handled before testing.
If your dog has struvite bladder stones, then acidifying the diet, along with treating the infection, can help dissolve the stones. Ascorbic acid (a form of vitamin C), and distilled water can help with this. , Acidic foods include chicken, beef, eggs, fish, pork, cottage cheese, yogurt, rice (brown and white), beans, nuts and all seafood. "
....
calcium/oxalate:
"Calcium Oxalate crystals can also be found in a healthy dog, but are more prone to develop into stones in some dogs. The pH in dogs with these types of crystals is usually acidic or neutral.
It is thought that some dogs that are more prone to these types of stones have an inherited weakness that prevents them from forming nephrocalein, which prevents calcium oxalate stone formation. While these stones are mostly treated by surgically removing them, there has been some success with reducing the oxalate rich foods in the diet and working to alkalize the urine pH.
Alkalizing foods include apples, bananas, cabbage, broccoli, beans, potatoes, pumpkin, millet, honey, alfalfa, non-distilled vinegar (organic apple cider vinegar), squash and most fruit and most vegetables.
High oxalate foods to avoid include beet greens, rhubarb, spinach, beets, raw endive, dandelion greens, okra, kale and sweet potatoes. "
Regarding nephrocalcin I have read and heard in several places that the lack or under production of it is seen in every case of calcium oxalate stones. An animal being susceptible to these stones is said to often be a hereditary problem and mostly affects male dogs. It is said that adding B vitamins.. B6 more specifically I think will help decrease oxalate formation. But I'm not sure on that. You will notice I put 'it is said' a lot and that is because I personally have no proof one way or another, not being a vet.
I'm sure if I have forgotten anything then Connie will add some info or correct me, I do believe she knows far more than I do!
Hope this helps.
Edited by Jennifer Marshal (02/19/2008 04:56 PM)
Edit reason: spelling