I'm actually not concerned about the metacam dosage being 0.03ml, even with it being 1.5mg/kg. I don't know who has said that 0.01ml is the maximum dosage for hamsters being given dog metacam, but it's false. If the metacam you've been given is 1.5mg/ml, and let's just say the average robo is 30g, the correct dosage
is 0.03ml. It'd be; (1.5mg/kg)(0.03kg)/(1.5mg/ml) = 0.03ml dosage.
The intense concentration would be fairly common with animals in large amounts of discomfort. I think this is where your vet is coming from;I know with rabbits, they metabolise medicines far quicker than dogs and cats, so are usually given a much higher conc. for even simple surgeries. I don't think she intended for it to come across that hamsters need more (volume) of metacam than was previously thought; and instead (perhaps) meant to imply that they require higher concentration?
It's extremely careless of the vet to point out the wrong readings on the syringe to such a drastic measure - and honestly, that mistake alone would be enough to send me running for the hills haha - but as far as dosage goes, I can't (personally) see anything wrong with it.
ETA;
Just to explain where i've gotten 1.5mg/kg from; Pardon, it's going to get messy;
You say you were given 1.5mg/ml of metacam, so to figure out the mg/kg we do the following;
(dosage prescribed)(concentration/ml)/(weight of animal/kg):
In this case; the dose you've been given is 0.03ml, the concentration is 1.5mg/ml, and I'm assuming your robo is average by giving his weight as 30g. We then sub this into the formula as follows;
(0.03ml)(1.5mg/ml)/(0.03kg) = 1.5mg/kg.
Like I said, I don't know who or where states that hamsters cannot have dog metacam in excess of 0.01ml. But as far as I can see, it's incorrect and the dosage & concentration you were given are all perfectly safe for lil' Nugget to have.