Well, no Orijen is a relief!
Now, before you go...a word of caution about the anti-inflammatory the Vet prescribed.....
I know that Metacam is licensed for use in cats in AU. One thing you need to know is about its potential effects and about dosage.
Metacam is a kidney-killer unless it is used at miniscule dosages.
There is a very recent study (done in AU, interestingly) that demonstrated its safety and efficacy at a dosage about 1/10 of the licensed dosage...that should tell you something about its "strength"/potency....so, my brief message to you is, the less, the better. (In North America, Metacam overdosing is an epidemic, and cats are showing up "everywhere" with kidney failure...see www.metacamkills.com
Here is the Australian study re reduced dosages
If I were in your position, I'd speak with a trusted pharmacist, showing him/her the bottle and syringe and a copy of that abstract....s/he should be able to tell you how to reduce the dosage to the safer levels.