Good morning, and thanks for the question. Apologies for the delay, I just signed on this morning and saw your post.
How is your goat doing this morning? Based on what you described, I can only say that your buck is suffering from a urinary blockage caused by bladder stones, and should be seen and treated immediately. This is a common condition in male goats, and is due to the small size of the urethra. I find very often that one small stone, less than the size of a BB, will have become lodged in the very tip of the penis, known as the “pizzle”. If one has some luck on their side, the pizzle can be removed along with the stone, allowing the buck to urinate freely again (however he will no longer be able to breed). The downside, however, is that this usually means that there are many more stones in the urinary bladder, and I advise that an X-Ray be taken to determine the severity of the condition. Surgery is often required to clear the bladder of stones, and even then the condition can return. There is also a surgery known as a perineal urethrostomy, where am incision is made in the urethra just below the anus, and the buck will then urinate from there, bypassing the small urethra and penis.
However the most important thing at this point is to have your buck seen ASAP. This is a life threatening condition, as the urea from the urine builds up in the bloodstream, which leads to kidney failure and death. Please, if you have the means, get your buck to a large animal Veterinary Facility immediately.
Best of luck to you. Please let me know if you have any further questions.
-Dan C., DVM