Hiya! So, personally when I use Osteocare I use 1ml twice a day for the first day, then 1ml once a day for the next day, then for another 5 days I give 0.5ml once daily. I would be cautious using it longterm as it can lead to bladder stones. Adding bran to the diet would certainly help as the phosphorus content will assist their body in actually using the calcium. But of course the rest of the diet will need to be taken into consideration as there's a bit of a science behind getting calcium and phosphorus ratios correct which is a bit of a faff to be honest. Adding a little bowl of bran will certainly do no harm during a short course of osteocare (no more than the 7 days) just be mindful that if your piggy is completely immobile then they will need extra fluid and assistance in moving around to agitate any extra calcium in the urine to help it pass.
What I do is, providing the legs, hips and lower spine will tolerate it and won't be painful, cup the back end and encourage gentle walking around on the front legs while again, very gently, creating slight bumping up and down movements of the back end to replicate the movement of the back legs, this should get things in the bladder moving so it doesn't settle at the bottom and cause irritation, sludge, stones etc or lead to a UTI. Watch for gritty pee and stop the osteocare if you notice any signs of discomfort while passing urine.
A barrier cream on their bits and feet may be helpful just in case of any urine leakage.
A decent alternative would be, giving an additional veggie meal once per day, a few hours away from pellets and other veggies, consisting purely of kale. Kale has the perfect ratio of calcium to phosphorus and will give a nice calcium boost without having to worry about balancing it out yourself and can be done for longer than giving osteocare as the risk of stone formation is lower.
As Wiebke says though, thankfully this issue is becoming less of an issue thanks to more appropriate diets. My only major concern would be calcium crashes due to renal osteodystrophy and similar. Unfortunately a lot of piggies carry the gene for this problem but show no signs until they suddenly do, in which case adding extra calcium generally won't do much to improve mobility. Pain relief will be the main goal, if you go the osteocare route and it doesn't resolve the issue quickly (and if it is a calcium crash generally recovery is quite quick after giving calcium) I would see about getting xrays done to be on the safe side, if you haven't already.
Good luck with your piggy!
