This is Dr. Christian. Welcome to JustAnswer.
Have you already given a dose of metacam?
Has she had any medications lately? How much does she weigh? Does she have any other medical conditions?
Try giving her a 1/4 of an 81mg aspirin tonight. Only give one dose since your vet may want to prescribe something different tomorrow. The ER vet would have stronger meds but if that works tonight you can wait until morning.
I would then. She can get something stronger at that point.
No problem. The dose is about 10mg per kg. She is about 1.8kg so that is about 20mg. Good luck. I hope she feels better.
You are welcome. Good night.
If you have more quesitons please let me know.