Welcome to Justansswer! I am Dr. Altman and happy to assist you both today!
Sorry Jasper got into some trouble this evening!
This drug itself can be used in dogs for the treatment of glaucoma so there is no real toxic worries. As far as an "overdose", if that amount were used in the eyes, it would be considered an overdose, but even with overdoses in humans, there doesn't appear to be any reports of a problem.
SInce this was ingested, I suspect there will be some absorption through the mucus membranes in the mouth, but just how much, it is hard to say. Even so, it overdoses in the eye are not a big deal, I wouldn't be too worried about ingestion. You may note his pupils to constrict in response, but if it does, it should wear off within a short while. Since the drops are not in a solution carrier meant to be ingested, it may cause some drooling or mouth irritation. If he will allow it, rinse the mouth out with water or allow him to drink and that should help to rinse away any residue.
I hope that helps. Please let me know if you have any further questions. I am online another 20 minutes this evening...
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