Changes in behavior are to be taken seriously

The cats I have taught me to watch out for unusual signs that they might be suffering from a physical condition. The body of a cat as well as the human body will tell everyone around them something different is going on with their body. Make it a point to never ignore signs of something different going on with your cats.

 

This is a good point. Cats instinctively try to hide their pain because it can mean trouble for them in the wild. One thing I learned is that purring isn't always a sign of contentment - cats will also purr when distressed. I also found that both of my cats changed their litter box habits when they began to feel ill (possibly associating the litter box with pain). It's especially important to pay attention to your cats' behaviors because they will not signal that they are in pain if they can help it.

 

I'm glad you posted this comment, because my one cat litter box habits changed awhile back. I never thought it was due to pain. I'll remember this information. He's stopped doing it now. It maybe because he's been diagnosed him as having diabetes. He may be having urinary pain. Does that sound right?

 

As far as I know, the urinary pain may be also the reason why cat make poo or wee outside their litter box.
And I fully agree with this purring thing - it's kind of a resonans that helps a cat to feel better, to minimise a pain.