What prompted bloodwork to be done in the first place? Was your cat exhibiting some kind of symptoms?
I ask because in my years of experience with cats and bloodwork in cats, it's very common for platelet counts to be "low" due to "clumping" of the platelets, which is pretty common (the platelets clump together and then, under the microscope it appears there are low platelets when it fact it's not really the case). Can you ask your Vet if "clumping" is the cause of the low platelet count?
Here's a Q&A online, from a cat owner whose cat was found to have low platelet count and an Online Vet responded, better explaining how a common cause of low platelet count in cats is due to "clumping" (or platelets sticking together):http://www.justanswer.com/questions/...t-back-showing
I'm a human RN. I am very familiar with bloodwork in humans and a lot of it is similar in cats. I learned all of this a long time ago when I got a copy of my cat's bloodwork results and I nearly flipped when I saw such a low platelet count - the issue of 'clumping' was explained to me.
I'm not saying this most likely IS the cause of your cat's low platelet count but it is a possibility and one you'd want to rule out/confirm before they go treating your cat for this when perhaps treatment isn't even necessary.
Just something to talk to your Vet about, whether this COULD be a possibility - particularly if your cat hasn't been showing any symptoms (bleeding or bruising easily, etc)