Do MC Cartridges Deteriorate over time

In theory, at least, the elastomers in the suspension can deteriorate over time, particularly if exposed to ozone and other such pollutants.  But, I've heard plenty of cartridges in the thirty year old range that sound fine and have not suffered from such problems. 

Way back in time, I had Shure cartridges that did not seem to last that long even though I was careful with setup and kept my records very clean.  When inspected, the report I got was that the stylus looked almost new, so what I was hearing was either the suspension going bad or stylus wear that was not that easy to see.  Whatever the cause, I have had MUCH better luck with wear with my MC cartridges (good thing, given the MUCH higher prices).

Aside from accidental damage (by far the biggest cause of cartridge failure), most of the better MC cartridges seem to last a very long time.  Most of the non-accidental premature death that I've seen had to do with internal wiring failure (evidenced by one channel going stone dead).

Thanks 

The good news for you is that you have no way of knowing how it might have sounded 15 years ago.  So, if it sounds good to you now, there is no use in worrying.  And as others have implied, there are expectations that cartridges deteriorate even in storage, but the sound quality one can often derive from even vintage cartridges calls that axiom into question.  

I own several cartridges mainly MC some with 40 years of life (Nakamichi MC 1000 / Ortofon MC30) and have no problems, as explained to me a cartridge repairer is sufficient when they are not used to close them in their own packaging and not to let light take over.
But there are more sensitive mc cartridges than others about the dumper that could deteriorate; a dumper that is very durable and lasts for decades is the Monster Cable Genesis practically (almost) eternal while for the dumper of the cartridges mm they are very perishable worsening the tracing and the sound quality.