Kidney failure?

Question
My male cat died at 12:45 AM two nights ago.  He was 20 years old and was a loyal friend.  He loved to sit only on my lap to be stroked continually.  He loved to go outdoors and had a good life, with lots of love, good food, and good care.  What more can one expect from life?  Months ago he started drinking more water than usual, but he had no other problems.  Then he began to have some stiffness in his rear legs.  This slowly got worse and worse, but he continued to eat well and maintained his daily routines.  Then he got worse faster with his stiffness in his rear legs, and he weakened. He sometimes stumbled when he walked.  We assumed it was kidney failure and that nothing could be done for him at his advanced age.  Then he stopped eating or drinking water. Two days later, finally, he could not walk.  I laid him in his bed, and soon I realized he was dying.  I stayed with him every minute, from about 9:30 PM.  He would lift his head and look at me when I came close. Numerous times as he lay there he would weakly moan or meow, and each time I would gently stroke his head and talk to him.  He may not have heard me because he was deaf, but I talked to him anyway.  I put a cloth over him to keep him warm.  This continued all evening, but he grew weaker and weaker.  Yet, he always responded to my presence. I noticed that his eyes were dilated, and they did not respond to a bright flashlight.  But he held on, meowing occasionally after which I would pet him and talk to him.  The last time he meowed, they were two, more gentle meows.  Then he began taking sudden sporadic breaths, and I knew the end was near.  By now he was perhaps in a coma, but his eyes were open.  This continued for maybe 5 minutes.  Then he took another big gasp of air and quietly exhaled in a sigh, and he was dead.  It was 12:45 the next morning.  It was actually quite peaceful, but I was heartbroken.  My devoted friend of 20 years was gone. I closed his eyes and left him in the restful position in which he died.  I went to bed, and in the morning he was completely stiff and rigid.  I dug a grave and buried him.  It was hard.  He was almost 21 years old, but I wonder if he actually had kidney failure.  He had no other symptoms except a moderately increased thirst and stiff rear legs.  Should we have taken him to the veterinarian when this first occurred?  Otherwise, at age 20, he was very healthy except for his deafness.  Can you offer any suggestions on this?  I am just curious.  Was it kidney failure?

Answer
Hi Paul,

I'm so sorry for your loss.  Imagine what you and he had been together over 20 years!  Remember the good times and know that you gave him a great life.  And 20 years for a cat is nothing to sneeze at!
Its impossible to know just what killed him, kidney failure is certainly a possibility, its very common in older cats, and it does manifest itself as increased thirst and urination, as does diabetes.  I have two right now, ages 11 and 12, who are in the end stages of kidney failure.  I do sub-cutaneous fluids if they'll let me but I don't push it.  I think quality of life is better than quantity.  The stiffness in his back legs isn't necessarily a result of kidney failure, he may have had some arthritis that was aggravated by the other condition.  Only blood tests could tell if that was the cause but I doubt you could have done anything to prolong his life.  Cats usually hide illnesses until its too late for us to do anything; its an instinctual thing to protect them from predators who might see them as easy prey.  Its just as possible that his heart simply gave out because of his advanced age.  Either way you gave him a nice peaceful, safe passing for which I'm sure he's grateful.