The most accurate and quickly accessible answer is bound to be provided by your local pharmacist.
My recollection is that it is time-limited - memory says about two weeks.
Whatever about that, I hope you understand the importance of finishing the entire prescribed course of any a/b.......not "preaching", just an info statement from me!
She has 3 days lefg on it and there still half a bottle left of it it was almost full wen I got it so wen she is done in 3 days there still be left overs of it I was wondering how long it last bc if Blankets infection came back and the vet says needs a second course I could give the left overs but if it only last 2 weeks then I might have to get a second bottle if the infection comes back