I was concerned that I never heard back from you, and since this could potentially be an emergency situation, I wanted to get you some information. If he is trying to urinate a lot and very little to no urine is coming out, I would get him to a vet immediately. He may have a blocked urethra and cannot get the urine out. It is common in male cats and can back up in the kidneys
, causing the kidneys to shut down and toxins and electrolytes to build up in the system, which can lead to heart arrhythmias. They usually get blocked from a mucus plug or a stone. Both can come about from a urinary tract infection and, more commonly, a bladder inflammatory disease called Feline Lower Urinary Tract Disease (FLUTD). If a fair amount of urine is coming out, he is most likely not blocked but should still see a vet soon to evaluate for a UTI, bladder stones, FLUTD, bladder cancer, kidney problems and diabetes
. Please let me know if you have any other questions or concerns. Hope this helps. My goal is to make sure that you get all your question answered and all the information you need. If you are satisfied with my answer, PLEASE RATE IT. Rating it is the only way I get credit for helping you. If you feel like it is not helpful to you, or if there is more information you need, please respond back to me before rating. Realize that our conversation is not intended to diagnose or treat a condition. There has to be a valid veterinary-client-patient relationship established with an exam, according to law. You should always follow up with your vet.