Thanks, opening the box there is not expiration date inside on the applicators.
I looked up the subject on the web and noticed several that claimed no date equals a counterfeit. I have no idea what that means in terms of quality but suppose ti could be nothing but a clear liquid.
Then I went to the Frontline site and it claims the shelf life of sealed applicators is not a concern, i.e., it dose not have an expiration date. Opened applicators is a different matter, I suppose. So if one buys a larger size than they need and plan to split the contents of an applicator they may have a expiration concern, but I suspect if kept in a newly sealed container and kept in a dark dry place the medication would hold for several months at least. I do not have any data on this last point and have not researched beyond the fact I know this is done.
If I had two or more dogs to treat I would be very tempted to buy the larger size and split it among the two or more dogs, here assuming my two dogs were not already the maximum size, what is that 120 pounds? The only concern then would be the measurement of the liquid, as it was all used at the same time there is no hold-over concern.
Mine doesn't have one either. I do remember that I worked with a vet tech that said that the shelf life is extremely long and that she had never heard of any going bad.
Looking at my box of Heartguard for dogs I see it has an expiration date on the box and on each individual tablet.