Mascot had giardia for 3 months! It was nearly impossible to get rid of.... we went thru round after round of meds. His problem was he was also a poo eater as a pup, so he would reinfect himself at night when I couldn't stop him. We gave him forbid which was suppose to make his poo taste bad but that didn't stop him either. I had to stop working and stay home with Mascot until he got all better. I thought the day would never come! And the 1st time I saw hard poo I nearly did a cartwheel! After 3 months, and several bleached outfits ( I used so much bleach...my house reaked of it for months and my clothes and grass in the yard payed for it) but eventually he got all better. It may sound crazy but I have put the most work into Mascot then any pet I've ever owned, but I think I love him the most..... but we won't tell any of my past babies I said that. Good luck, and the key really is bleach bleach and more bleach.
