Thanks for the answers to my questions and additional information.
You sound like you've got a lot on your plate and are doing the best you can...which is all anyone can do.
There could be several different reasons why Tucker has the blood that you're seeing although without testing (such as a urinalysis), we may not be able to pinpoint the exact problem:
1. Since he's not neutered, he may have a condition called Benign Prostate Hypertrophy which basically means that his prostate is enlarged. Dog with this condition typically don't have any symptoms at all but some will produce a bloody urethral discharge from the penis (the dripping blood that you mentioned) as well as bloody or port-wine colored blood when he urinates.
Many of these dogs will only produce the blood at the end of the stream but this isn't true for all patients.
As the name suggests, this is a completely benign condition although I usually do recommend that these dogs be neutered if at all possible since the prostate could enlarge to the point where it compresses the colon (these dogs might start to strain when they defecate).
The symptoms of blood from the penis and in the urine usually disappears after these patients are altered.
2. Of course, the most common cause for these symptoms is going to be a a urinary tract infection. One possible consequence of this condition if left undiagnosed and untreated would be that bacteria could travel to the kidneys and set up infection there...which potentially could be fairly serious if enough damage is done.
Amoxicillin is a drug which was overused many years ago and urine bacteria had become resistant to it. However, that doesn't always seem to be the case these days and this drug may be effective for some patients. I know some vets who routinely now dispense Amoxicillin for their uti patients in the absence of a culture and sensitivity (to determine the best drug to use).
The dose of Amoxicillin for a 70 lb dog would be 700 mg twice a day for a minimum of 2 weeks (although I'll treat some patients for at least a month). This means that he'd have to take 3.5 tablets at one time if you have 200 mg tablets.
Of course, it would be illegal for me to advise the use of a drug for a patient if it wasn't dispensed or prescribed for them but I can provide the dosage amount which is what I have done.
Supplements with cranberry won't be harmful but aren't likely to help once a uti has already been established (in case you were wondering). Acidifying the urine can help to prevent infections but doesn't resolve them any faster once they are established.
3. Bladder stones can also cause the signs you're seeing but would require an x-ray or ultrasound to diagnose.
4. And, prostate issues such as infection or even cancer, unfortunately, could also cause these signs.
Given your limited options and current situation, I can understand that it's not likely that a workup can be done for Tucker to determine the underlying cause of these symptoms. If he were my dog and I were in your shoes, I'd treat him with the Amoxicillin for at least 4 weeks (since he's had the problem for so long) and hope that he just has a uti which didn't receive antibiotics long enough. Or that he has #1 and will just have intermittent issues until or unless he's altered.
As I mentioned above, his symptoms could be consistent with any one of the above conditions so it won't be possible to narrow down the list without a lot of testing, unfortunately.
I'd also encourage fluid intake to help flush out his bladder regardless of the problem.
I hope this helps. Deb