According to these links magnesium is a very important mineral for the efficient control of calcium , as well as other things , and "not" just for humans!!!!!!!!!!,
And seeing that Guinea pigs often prone to suffer from calcium related bladder problems, it's got to be worth looking at,
Example quote from link > http://drsircus.com/medicine/magnesium/magnesium-and-calcification
It is magnesium that controls the fate of potassium and calcium in the body. If magnesium is insufficient, potassium and calcium will be lost in the urine and calcium will be deposited in the soft tissues (kidneys, arteries, joints, brain, etc.). Magnesium and calcium complete for many of the body’s chemical pathways.
Quote from link> http://www.whfoods.com/genpage.php?tname=nutrient&dbid=75
About 50 to 60% of a person's magnesium is stored in the bone, and as such, it plays a key role in bone metabolism. Researchers have found that even a mild ongoing magnesium deficiency can lead to a significant amount of bone loss.
Part of the way that this occurs is that when magnesium intake goes too low, levels of parathyroid hormone go down. This leads to a reduced absorption of calcium in the intestines, "as well as increased loss of calcium and magnesium in the urine" . Unquote>
magnesium is even used to in rabbits to clear sludge from the bladder
Use of liquid magnesium in rabbits
with chronic sludge
If Guinea Lynx were to collect some data on which pigs developed osseous choriostoma or metaplasia, I would bet many are those that got little sunlight (with a normal calcium diet) or had a high calcium diet and maybe also had some genetic component. I would think that there is also some link between osseous choriostoma/metaplasia and heart disease.
I have used epsom salt baths (it works for humans) and applied magnesium oil on their skin (behind their ears). So far my remaining guinea pig's eye has not worsened and he is on a normal calcium diet.