Hi, I can help you with your question today.
We can see several conditions which might cause increased thirst, diarrhea, and appetite decrease.
The most common reason would be kidney disease.
We could also see hyperthyroidism or even cancer causing these signs.
The best way to determine what is going on with him will be to have him seen by your local vet.
I would start with a physical exam and senior blood panel.
This will go a long way to diagnosing what is going on with him, so that we can learn his prognosis and begin a treatment plan if you choose.
If you have more questions or if I can help in any other way, please do not hesitate to ask! If you would like to accept my answer, please press RATE OUR CONVERSATION.
Please remember to only rate my answer when you are 100% satisfied. I will be happy to continue further and do everything I can to provide you with the service you seek.
The vet we have spoken to thinks it is kidney failure and suggests that the fairest course of action would be to have him put to sleep. We had to have a second opinion and you diagnosis seems to confirm theirs. I suppose we were hoping for something different.
I'm so sorry, but it does sound quite suspicious for kidney failure. We can confirm this absolutely with some blood testing, most hospitals can even do this on site and have answers in about 20-25 minutes.
The results from blood and urine tests would be very diagnostic for kidney problems. We would expect to see the BUN and creatinine elevated with a low urine specific gravity (poorly concentrated urine).
We may also see anemia, elevated amylase, elevated phosphorus, and potassium changes.
Thank you ever so much for your time. The rating will be excellent.
You're very welcome. Please let me know if you need another opinion or review on any lab work you have performed.