Woke up on Saturday and my buddy can't seem to pee on his own.  Tried to put a little pressure on his bladder and it's full, just get a few dribbles out.
Took him to the emergency vet and they inserted a catheter and drew off ~800cc, after which he felt much better.  Antibiotics and anti-inflammatory to see if that helps him out.
He peed some on his own that night.

Same thing Sunday morning, drained him again and did an ultrasound, looks like his prostate is swollen, maybe from an infection, maybe from cancer, can't be sure without more tests.
They sent me home with a couple catheters to empty him twice a day for a few days to give the meds time to work, if they're going to work...  If not then decisions will have to be made soon...  I don't want to put him through having his prostate out at his age.  I'll be calling the place that did his hernia surgery (they do great work) this morning to see if they have any suggestions.

He's going on 13 which is amazing for a Boxer, and he's been otherwise healthy other than a hernia a few months back during which he was fixed, which should have caused his prostate to shrink unless it is in fact cancer.

Getting old sucks... he's still a puppy at heart...

Anyone else deal with this kind of issue with their pup?

No vets in the house?

Vet wants to switch from Clavamox to Baytril, supposed to penetrate the prostate better.
Also wants to add Prazosin and very low dose Valium as antispasmodics.

Been cathing him twice a day for a few days now, he's grown accustomed to the procedure
Only takes about 5 minutes now.

https://www.ar15.com/forums/general/Had-to-say-goodbye-to-my-buddy-this-morning-/154-2027513/

Be aware that as the prostate isn't terribly vascular, you often need to be on antibiotics longer than you might think.

Give that dog some love for me.

A week of Baytril and 2 weeks of Clavamox didn't seem to do much for him, and it was getting noticeably tighter to pass the catheter, and blood in the drawn-off urine after all that.  Had to make the hard choice, but it was the right one for him...

Ah, man, I'm sorry I responded without seeing the updates.  You've got all my sympathy.  Dogs are the opposite of everything else you buy... you get all the good up-front, and pay the price at the end.  

I can't help you with any advice, but I hope you figure this out asap. Best of luck.