Thank you for your post. Based on the limited information you have provided, I am presuming that your cat is a male kitty.
I am very concerned about the possibility that your cat has a urinary obstruction. If this is true, it is imperative that he be seen by your local ER clinic right away. One way that you can try to determine that at home is if you can feel a golf ball or baseball in his belly, than he is likely obstructed. If a small amount of urine is coming out, he may not be completely obstructed, but it is still an emergency.
The other possibility is that he has something called Feline Lower Urinary Tract Disease (FLUTD). Some cats develop the signs you've described and it typically lasts 7 - 10 days. However, it is important to rule out other causes:
- urinary obstruction
- urinary tract infection --> this is VERY uncommon in cats, unless they are older and have underlying kidney
- stones in the urinary bladder
If he does have FLUTD, there is no effective treatment. Some cats will respond to SQ fluids or anti-inflammatory medications. The key is often to decrease stress and to encourage cats to drink more water, which can be accomplished by changing the water in bowls multiple times per day, buying a kitty water fountain, feeding canned food
. Addling tuna juice to water, etc.
I hope this information has been helpful. Please let me know how I can be of further assistance.