I wanted to share my experience with chronic kidney disease (CKD) with my dog and hope it helps others. This is quite long.
My dog passed away from CKD at 14 1/2 years old. 11 weeks after her first diuresis, I let her go. I believe her CKD was caused by Rimadyl and made worse by Metacam. She only took Rimadyl for like 4 days but after that, her appetite decreased and never rebounded to what it was before. Rimadyl is known to cause stomach issues/ulcers so that was initially what her decreased appetite was attributed to but as I stated, her appetite was never the same. 2 months after taking Rimadyl, due to her decreased appetite, labs were done. Her BUN, creatinine, and SDMA were all normal. Due to her arthritis, she was given Metacam about half a year after she took Rimadyl which made her kidneys much worse but I did not know that at the time.
Her appetite got worse and worse so she had labs done again about one year after her previous labs. This time her creatinine was 1.7 (high) (dog's creatinine should be less than 1.4), BUN 54 (high), phosphorus 6.0 (borderline high). SDMA was normal. The vet misdiagnosed her though. For some reason, she attributed my dogs's symptoms to pancreatitis (my dog did have chronic pancreatitis) but her main problem was CKD, not pancreatitis. These values, along with her symptoms, decreased appetite, not eating as well as before, should have been very straightforward. When a different vet saw her (after my dog got really, really sick), she immediately diagnosed my dog.
Unfortunately, I did not question the vet who diagnosed pancreatitis so my dog was not treated for CKD for a few months. One day, my dog stopped eating her dog food, refusing it almost totally and vomited at which point she was finally diagnosed by the other vet with CKD. I took my dog in for diuresis for 2 days and her labs normalized. For about one month, she was doing pretty well, better than she had been for a while. She was still a bit picky about eating and didn't eat her usual dog food but did eat other food. She was running on walks and had a lot more energy. Unfortunately, I was unable to put her on a kidney diet as she also had food intolerance issues. The one kidney diet she could tolerate, she refused to eat. So she was not on a commercial or homemade kidney diet which may have made quite the difference. I did not think my dog would be able to tolerate most of the homemade kidney diets I researched as most consisted of beef or chicken and she had issues with those proteins. She did get subcutaneous fluids, about 3X/week, and she did have a pee accident here and there. She had been checked for a urinary tract infection when she was diuresed and did not have one.
About 5-6 weeks after her diuresis, she started getting worse, refusing more and more food. She was on and off Cerenia and Entyce. About 8 weeks after diagnosis, I took her in for a second diuresis as she vomited and was not eating well. I thought it would help her again, like it did before. This time she was diuresed for 3 days but her lab values remained the same, they did not go down. For about 2 weeks after this, she was still fairly active in terms of she played a bit, maybe for like 5 seconds, and she still enjoyed the few and short walks we took. However she was refusing more and more food and it was clear she was more and more fatigued. Her back legs were weak, she could not go up the doggy stairs like before and when she pooped, she had trouble forming her stooling posture and would stool a bit here, then move and stool a bit there which is something she had not done before.
When did I know it was time to let her go? She seemed to go downhill quite fast, almost overnight. One day, she was still somewhat active, and the next day, she was like a zombie. She didn't seem to enjoy anything. She was still aware, I could tell she was, but she didn't greet the family as she used to. She used to look out the car window but now she did not, she just slept in the car. She didn't want to eat anything. The only way I got her to eat her last week was to give her different things each day, pupperoni, ground beef, keebler crackers, hot dog. She would eat something once and then refuse it the next time and she was eating probably 25% of the calories that she needed to be eating. She was on Cerenia daily so she didn't vomit and hopefully, it made her less nauseous. Her tongue hung out and it was cold, not warm as it usually was. She used to give kisses and now she didn't. She didn't want to go on a walk, which was one of her favorite activities. She labored as she drank water, the way she drank it was different, it wasn't normal. All she wanted to do was sleep.