op I just found this info and thought of you so wanted to post this info for you as i know you had questioned this
http://wvc.omnibooksonline.com/data/.../2010_V137.pdf
Carprofen (i.e., Rimadyl) causes hepatotoxicity in dogs, especially Labrador retrievers.
The histologic changes seen in carprofen hepatotoxicity can resemble chronic hepatitis, so be sure that
you have an adequate history. Also, be aware that hepatotoxicity may not be seen until 1-2 weeks after
starting a drug; in fact, the patient may have stopped taking the medication several days before clinical
signs of toxicity occur.