I did not take you for a neglectful keeper and I hope my reply to Adam in the previous thread did not sting. I was trying to make a point to him. By your posting and quick response in your trip to the vet said a LOT! Too many times someone will not take that step b/c of the money involved; hearing things like "the vet costs more than what I paid for the chameleon." GRRRR, but that is another thread altogether. This was obviously not the case with you and I was trying to reply in a non-hostile way so as not to alienate you. So I thank YOU for taking this the right way and for caring about your Houdini 
we will do our best to get him back on track (and maybe even find you a new vet!)
Meds: Need to be sure which calcium supplement he gave you. There is Calcium glubionate and Calcium gluconate. If it is Calcium gluconate (sometimes called Neo Calglucon/NCg) he is way off on the dose or you wrote it wrong. All supplements and medication are based on the weight of the animal. Did he weigh him? what was his weight? Dosing for NCg is .01cc/10grams 2x/day (or double the dose once/day. Simply divide his weight by 1000 for a 2x/day dose and double if you are giving it only 1x/day
Example: if he weighs:
100g he should get .1cc 2x/day or .2cc 1x/day;
150g dose would be .15 2x/day or .30 1x/day;
80g he'd get .08 2x/day or .16 1x/day. So notice where the decimal point is. If he said 15cc that would mean your cham weighs 15,000 grams...I sort of doubt that I assume he gave you a syringe and plastic tip? Be sure you know which line on the syringe to fill to.
Did he give this to you in a liquid form and show you how to properly administer? Chams can easily aspirate fluid if not given properly. It can be tricky one handed so if you have someone to work with you it will be easier. I always did Luna by myself and sometimes she was OK with it others times not. The one with the NCg is that he may like the taste, which helps,
If it is the Calcium glubionate I am not sure of dosing but someone else here may and I have a call into my vets office to find out. I cannot imagine your vet is so incompetent as to not give you the proper dosing, but if he did not recognize dehydration…
What is the name of the antibiotic? I have limited knowledge about meds since I only gave them once (the NCg I have lots of experience with so know that I am telling you correct info) and it was with a syringe and needle – not a fun thing for either me or Luna 
I'm only giving you part of my reply so I can get it posted. This forum has a tendency to slow down on weekends, but a few of us seem to always be checking in (me, Will, and a few others)and since you and your guy need some rather immediate assistance I wanted to get this much info to you. More to come...(drippers, etc.)
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Chameleon Help & Resource Info
0.1 Veiled Chameleon - Luna. She's now hanging from her big jungle gym in the sky
1.0 Beardie - Darwin
0.2 felines - Kyndra and Lita
0.1 African Clawed Frog - Skipper
0.1 Mad. Hissers and she is on the loose!
0.1 Chilean Rose Hair Tarantula - Rosa Leigh
0.1 Goliath Bird-Eater Tarantula - Natasha
?.? Pinktoe Tarantula - no name yet
