That's because desiccated is past tense. The other forms would be dessicate, dessicates, and desiccating. The "I'm starving to death" would be "I'm desiccating to death"

I think that's right. I would read it as hyperbole to refer to something still alive as desiccated, for sure. If you meant it literally, I wouldn't think of something that is even just dead but like, dried up and leathery, too -- if you're talking about a desiccated cow, I'm thinking more "beef jerky" and less "someone get the vet, and hurry." There are more natural options elsewhere in the comments; I offered mine more as "this is the more well-known word using that root" than "this is the most natural word a native speaker would produce."