Senior Moments Part 3: Chronic Kidney Disease in Cats

Part 3 in our series on senior pets, "Senior Moments" focuses on a disease we commonly see in aging cats and was written by Dr. Amanda Stephenson. Chronic Kidney Disease, or CKD, is estimated to affect 30% of cats over the age of 12 years. 

​How do you know if your cat has kidney disease? Cats are notorious for being able to hide their illnesses.  Often, changes in their normal behaviour are the only clues that they leave for their owner.  For example, suddenly your cat is hiding and is less sociable then normal. Of course, the opposite may be true and a cat who does not normally like to have a lot of physical contact suddenly is vying for your attention.  The abnormal behaviour may be a way that your cat is trying to communicate that they are not well or may even be trying to hide it. Sometimes these changes are very subtle so don't feel bad if you miss them.  Often owners don’t realize that their pet was "off" until they think back on it later. There are more "obvious signs" signs of illness though and hopefully you will be able to pick up on these more readily.

Obvious Signs of Illness in Cats

​1. Decreased appetite-by feeding specific meals rather then leaving food out for a day or two then owners are usually able to pick up on this symptom earlier.
2. Sleeping more, less energy-this may be tough sometimes to pick up on if your cat sleeps a lot during the day. Often owners think their animal is just getting old (this goes for all pets).

3. Weight loss-some cats are very fluffy so it can take longer to pick up on this if their cat is more " hands off " or independent then other pets (let’s just say it... FIDO usually needs more physical contact then our feline friends!).

4. Increased thirst and urine production- often cats start spending more and more time at the water dish, the sink tap, and/ or the toilet bowl. This is difficult to pick upon initially depending on their preference for water and especially if they go outside part of the day. Usually these animals are "hugging the water bowl" by the time it is noticed. 

​This is one of the most common symptoms owners report when they come to the vet clinic with their kitty. They will often complain of "accidents" on the floor and full litter boxes as the volume of urine excreted increases.

5. Bad breath and/or a sore mouth-sometimes when owners bring their cats in for an exam they are prepared for the possibility of dental disease but are surprised to hear that kidney disease can share these symptoms as well.  As kidney disease progresses the kidneys begin to struggle to get rid of the toxins in the bloodstream. They build up in the smallest vessels first causing inflammation. Some of the smallest vessels externally are located in the mouth-the gingiva leading to gingivitis which can cause bad breath and dental disease (secondary to the original problem of kidney disease). Another problem often found in the mouth are "sores" or ulcers because of this same situation and they can make it hard for a cat to eat dry food so owners will often report that they will only eat canned food.

​6. Vomiting and occasionally diarrhea or constipation- it is more common for an owner to come to their vet clinic reporting that their cat is vomiting or vomiting more then normal (that's a story for another day) then diarrhea. As long as their is stool in the litter box then it is easy to miss early signs of constipation (dry, larger volume bowel movements).

7. Weakness-this may be caused simply by not eating as much because of nausea due to increased toxins in the blood stream and anemia. Most people are not aware, but our kidneys secrete a hormone which tells the body to produce more red blood cells. As kidney disease progresses, this hormone isn’t produced like it should be and we can become anemic. 

​Severe dehydration can also lead to weakness and an owner is often shocked to hear this because their cat is drinking so much.  Unfortunately, the kidneys are not able to "hold on to the water" and they are urinating it out as fast as they are drinking it, resulting in dehydration and dry stool causing constipation as mentioned previously. 

​After reading about all the "obvious" signs of kidney disease I hope that you will tell anyone who feels badly for missing them that they shouldn't. Most of our feline friends are so good at hiding any illness that it is more common to miss the signs then to pick up on them.  It is likely that 75% of kidney function is lost before we can detect it even if a cat is brought to their vet clinic "early". The good news is that we have better medications, diets, and even supplements which can help support the kidneys. Often an animal being treated will have a much better quality of life and for a longer period of time then if they had been left untreated. 

Common Causes of Kidney Failure:

​High blood pressure
Infection-bacterial, viral
Cancer
Ingestion of a toxin
Obstruction caused by a kidney stone
Kidney blockage-urethral obstruction
Hereditary

Acute vs Chronic Kidney Disease

 The main difference between the two classifications of kidney disease is the timeline in which it occurs...ACUTE cases can be measured in days or weeks while CHRONIC cases are measured usually by months. It is important to a veterinarian because the clues to the cause of the disease can often be found in the duration. For example, infections and toxin exposure usually are cases where a cat is suddenly, violently ill are acute cases. Acute cases of kidney disease have a higher rate of reversal than chronic cases.