We recommend that you contact your veterinarian. In most cases, an animal would have to eat very large quantities of ant bait gel for there to be any problem. The product label and the MSDS are always available on the Advion Ant Bait Gel page if you need to contact your veterinarian. In the future, be sure to apply to the gel in small dots directly into cracks and crevices, so that the ants will have easy access to the gel and your pet will not.
The code on most insecticides of any sort including Advion Ant Bait Gel will be an indicator to the manufacturer of what batch the product came from and when it was produced or packaged. The shelf life and expiration is all dependent on how you store the product once you receive it. The product you received should have a shelf life up to 5 years from the date of manufacture.
To remove old Advion Gel you can first try hot soapy water. If that does not work vegetable oil takes it right up.