<human>: Can you summarize the given text in a few sentences?

I have had this dog for two months and her past is virtually unknown. I took her into the vet and had basic blood work / stool samples taken which all came up clean and well as a couple afterwards. I've pretty much been battling her loose stool / diarrhea since day 1. I started by switching food which helped for a couple of weeks then the diarrhea started up again about a week ago and she was becoming very lethargic. My nearly 7 month old pup was due for her last round of parvo so I waited until today to have her checked out (she didn't seem sick, just a tad lazier than normal). My normal vet wasn't there today who usually takes care of her and is such a nice lady, my dog LOVES her. Instead I had a grumpy old man who my dog was terrified of and he couldn't even complete the full physical exam. After telling him her symptoms and the time line he tests her for Giardia and sure enough it came up positive. He gave me Metronidazole and something to calm her stomach. Other then that I really had no idea what to ask him and was just uncomfortable with him in general. So i'm here wondering what else I need to do? I isolated my roomates cat, cleaned and scrubbed the water / food bowl, what now?
<bot>: Pup was diagnosed with Giardia, given meds and sent on my way. Anything else I need to know?