My 7 yr old terrier was spayed last december, for the last couple of months her tummy has looked red and she has had a smell about her - vet initially thought it could urine leakage but there wasn't really a wee smell so he put her on anti b's and i think a steroid injection. It did clear up but her tummy gets red (more so after a walk when she stays wet after swimming) and has a musky smell so i thought possible yeast infection and she had malaseb baths, this hasn't helped as the redness continues, plus she has red & thickened skin on her bottom part of back legs and front legs. Discussed with vet who said possible fox mange so has given advocate for 3 doses over next 6 weeks.
Tonight have checked her tum and she is really sore in two places either side of vulva area and it was wet, she had wet all round the fur close to her vulva which was sticky aswell - smell of urine. cleaned her with very diluted hibiscrub and dried and have applied sudocrem until i can speak with vet tomorrow. I have also smeared vasoline over the rest of her tummy to prevent further 'nappy rash' occuring. I feel terrible for her if we have missed this all a long and its my fault.  she seems sad.

what do the vets give to stop the incontinence and is it effective?

I have a bitch with slight spay incontinence and she is on Propalin. It has is 100% effective for her.
K 

Not sure these days but they used to give female hormones.