Some years ago I had a cow with a UTI. I knew this because I recognised the smell of the urine. (Anyone who has had cystitis will know the characteristic smell of urine from a bladder infection.) I got a homeopathic remedy from Crossgates Homeopathics, near Skipton, and in 2 days her urine was OK and the cow looking much happier.
I didn't call the vet because the cow was out at pasture and difficult to gather, and also because I had had good results in the past with homeopathy for simple infections. Also the remedy was easy to apply by just putting a couple of squirts on a bit of carrot, which she readily ate.
Now you might think this rapid recovery could be coincidental. But I still had best part of this remedy left after the cow recovered. I had a friend who was prone to cystitis, so when she said it had happened again, I gave her the remedy to try. She put a few squirts on her tongue and within a couple of hours the discomfort was gone! I gave her the bottle so she could keep taking it for a few days till the infection had gone and it went completely with no need to go to the doctor for antibiotics.
As you will know - kidney infections often result from untreated UTIs. So if the sheep is still under the weather, then possibly the antibiotics haven't worked completely and I would definitely recommend trying homeopathy to relieve her discomfort.
Another well tested remedy to relieve the irritation in the bladder is to add some baking soda to her feed or water. This reduces the acidity of the infected urine, and so stops the irritation of the bladder. This works in @ 30 minutes.
And finally, I would just like to add that i have been slagged off on here in the past when I have recommended homeopathy. The assumption appeared to be that I was letting the animals suffer by not going to the vet, and I was using homeopathy as a cheap and obviously useless alternative. Nothing could be further from the truth.
Homeopathy encourages the body to produce its own defences to bacterial infection and other inbalances in the body. I have used it effectively against foot rot, sweet itch, retained placenta, infertility, mastitis - to name but a few. It doesn't always work completely; but then neither do antibiotics, and I do use antibiotics as well. In instances such as, say a broken leg, I would always go to the vet. So I am NOT some naturopathic crank. I've found homeopathy amazing but it's up to everyone to make their own minds up; and if nothing else seems to be working - what have you got to lose?