Question about my aging cat's spine

she is 18, and i can see that she has a hard time getting around. she goes up the stairs very slowly and she doesnt jump on high places anymore.

ive been noticing it more and more and never thought of it and im not really sure if its normal or not (havent petted another cat in forever) but when i pet her back i can really feel her spine, like a bunch of lil bumps right near the skin. she isnt a skinny cat so i was just wondering if its like artritis making it that way or if its normal. Tweet