Hi, Marika M
At the age of 8 your dog is due for a senior workup, a physical, lab work and whatever else your veterinarian determines is necessary.
No one on the internet, no matter how much they consult Dr Google can tell you what is wrong with your dog or advise you accordingly.
Only a veterinarian that has examined your dog and reviewed it’s history can diagnose and give you an educated guess as to how to proceed with the care of your dog.
If I were you, I would select a veterinarian close to home and make an appointment, today.
All of the maladies you mentioned are possible, all require the care and treatment prescribed by a veterinarian.
Please try to listen….I have learned these things the hard way.
PS: Obtain a urine sample if you can, use a clean empty prescription pill bottle….sounds like it could be crystals. If you can’t, don’t worry about it. The vet can strait cath, it only takes a second and does not hurt the dog. It actually provides a more sterile sample.
