bladder stones in sows is a lot better than in males, with sows the stones can be sometimes flushed out due to them having a bigger urethra where in a male their urethra is a lot smaller and cant not be flushed out very easy...
if the stones are big then they cut an inch incision into the bladder and remove the stones via this way and flush them out a few times until clear...
survival is good BUT a low calcium diet is a must after for life which would be things like avoid kale, spinach, cabbage, to often and look into other veg ie peppers which are high in vit c but low in calcium...
she would also need to go onto cystease which can be brought via vet uk website for 100 tablets £20 which will last 200 days as the dose is half a capsule dissolved into 1ml water and given via syringe every day for life, this buts a lining onto the bladder and also helps to stop crystals forming into stones...
a boar i had in rescue had stones and recovered well but did need syringe feeding for 5 days with mush pellets every 3 hours and water mixed with probiotics every 3 hours. until he started eating and drinking on his own...
there is always a risk of stones coming back more so in the first 2-3 wks after the op so its important you can get them to drink as much as poss to flush their own bladder out the glass water bottles are great as they tend to drink more than with the plastic ones..
sadly i lost my boar 3 mths later as the stones came back, he was 4yrs old so quite old and it really affected him after the op and i just knew it wasnt fair on him...
but the chance of success is good with a diet change too.
make sure they have a pellet dry food not a muesli as muesli contains high calcium x
my female rabbit also suffered with bladder stones 1 week after i had her and passed it on her own, how she did i will never know, as there is a massive risk of the stone blocking the urethra and they cant wee and will die a horrid painful death..
here is the picture of the stone my rabbit passed
http://www.theguineapigforum.co.uk/showthread.php?t=56827
you need to ask for an x-ray if nothing is showing up ask for a contrast, as some stones dont always show up on x ray...
in the long run doing this will save you money as you wont have to faff around paying for antibiotics when in fact its a stones.
at least you will know where you stand with the contrast .
antibiotic wise you really need septrin its less harsh on the gut and is aimed at water infections.
while on Baytril its important your guinea has probiotics as baytril is very harsh on the gut and can cause antibiotic toxemia, the probiotics helps to repair the damage baytril does to the gut x
let us know how you go on?