T.F.
Get him checked at the vet.
Our 10yr old Cocker had a few accidents and we just thought maybe we didn't take her out enough. Then she started getting lethargic so I took her to the Dr and he put her in antibiotics for a week, thinking the cause was the cicadas she would eat when she went out at night. Gross!
A week later she wasn't much better. She's been very active and healthy all her life. So, we went back to the Dr, and through a blood test, discovered she was in kidney failure. Who knew... We tried all weekend to save her with fluids and we lost her on 8/17.
We feel guilty for possibly missing something but we know something happened in the 18 months since a normal blood test. She was well loved and we spent hours playing with her. You are the best judge when you know something is "off".
Please go to the vet. We are still heartbroken. Our 9 yr old poodle is doing ok but he sleeps on her blanket where her scent is still there. He's never been without her so he's adjusting. This heartbreak has been worse than losing a human loved one.
Good luck.