I've got a bottle of cd/t that I planned to vaccinate my two 4 week old doelings with today. but on the label it says use entire contents when first opened. I opened it about 2 months ago and it's been refridgerated since. can I still use it?? I've got an unopened bottle as well if I can't use this one, but i just don't want to waste this one if I can still use it.