When we first got Little Bit, the vet told us just to use 1/2 the vial the first month and then use the second 1/2 the second month. She just told us to store it in a ziplock bag. Silly me, though, I thought it was because she was so young. I guess I could just keep doing it that way though, since Little Bit is still less than 3# at 7 months.
Did they give you what the difference in strength was for cats? It surprises me that the cat solution is stronger. I thought that cats were usually more sensitive to poisons than dogs.