Don't think you need to worry about babesosis pissing actual blood. Generally with babesia they piss dark urine, dark orange to brown.
What Jack said has you pretty much covered. But if you have seen him licking obsessively, or gnawing on his genitals, this could also be a reason for the blood.
Also prostate problems can cause this, 80% of male dogs can have issues with their prostate over the age of 8.
Good luck man,
S_B