Coccidia and giardia in 7 week old chihuahua???

Okay heres my question: I have a 7 week old chihuahua, my husband bought him as a surprise present to me, while I myself grew up breeding chihuahuas he did not. The " breeder" told him the puppy was 9 weeks old, but my vet says otherwise. The first night I had him home my puppy went poo 3 times, diarrhea with traces of blood were seen. I immediately took him to the vet that night, because i was worried about parvo...thankfully no parvo was found however he does have coccidia and the beginning stages of giardia. Hes taking albon penacur and keo pectin...eating well and drinking...playful, a little more tired than he was when he first got here 4 days ago, but i mostly attribute that to his nightly activity.how do i make sure he's able to fight this off? any cleaning tips for my carpet, i cant use bleach obviously? oh and one more thing.he doesnt like to be warm, which surprises me because of his breed.hates covers and moves away from heating pad at night. dont want him to catch cold????