Welcome! My name isXXXXX am a 2003 graduate from UC Davis, and currently a Medical Director of a veterinary hospital.
I am sorry to hear about this concern for Riley.
Well, I would have really expected some symptoms of distress by now. Primarily, vomiting, diarrhea or loss of apppetite.
Also, if Riley was supposed to get ibuprofen, the typical dose is no more than 4 mg per pound. So, @ 13 pounds that is 52mg, and she maybe ate 200mg. Very possible, she did not eat it at all.
Here's extra information about ibuprofen toxicity:Ibuprofen Toxicity
I hope that information has been helpful.
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