The link between kidney disease and bad breath in cats
I've just discussed the link between periodontal and kidney disease in cats. There is also a link between kidney disease and bad breath in cats. The same link occurs in humans. Bad breath is sometimes referred to as halitosis. It is due to the excessive amount of urea in the bloodstream when the kidneys are malfunctioning. Kidneys filter out urea. The smell can be like ammonia which is the same smell you pick up when you go into the home of a cat hoarder because the cats have been urinating on the floor due to stress.
The link between bad breath and kidney disease is important because kidney disease is very common in domestic cats affecting between about 2% and 20% of all domestic cat but the prevalence is much higher in elderly cats above the age of 15 where it might be as high as 80%.
The information might be useful as a diagnostic tool in trying to work out why your cat has bad breath but there are other reasons obviously such as poor oral health due to reasons other than kidney disease such as bad gum disease and stomatitis, or something stuck in a cat's mouth or throat such as a bone.