Leslie, please don’t get discouraged if the antibiotics don’t work right away.
When my female had bloody urine due to a urinary infection it took a second and longer dosage of stronger antibiotics to completely get rid of it.
I hope your vet can figure out the reason for his peeing, or you might want to consider a second opinion. If it’s a behavior problem the vet should discuss medical treatment as well.
Anyway, nice to see you post again.
How are Graham and Kersey?
And who is Mindy?