hey aaron--could king have gotten worms or parasities from the puppy?
zack had bloody diarrhea off and on for a month when he was 4 months old, my experience of a lot of meds was that tylan was the best, and tylan was a good anti-diarrheal which eases inflamation in the bowel, could take a coupld of days to work. Didn't you use it before? Flagyl does the same thing, independent of their antibiotic properties, which may or may not work, depending on if there's a susceptable organism. I've read that people on these boards, sometimes give something like kaopectate, kaolin?
Belle was given that by her vet when she had bad diarrhea not long ago. It worked very fast.
i hope something helps and he gets over it.
if your vet prescribes salicylamide, discuss the common side effect of damage to tear production with them. it can be short term, longer term or permanent, but usually is short term. But cavaliers seem to be prone to tear issues already so if it's ever prescribed for zack again (as it was for colitis) i would ask about alternative medications, since zack did have the side effect. the vet immediately reduced the dosage when she saw that he was having eye symptoms from it. his tears have been worse ever since, although i don't don't know if this would've happened anyway. When i first got him, i was happy that he didn't have big tear stains like belle had, but since the salicylamide he has them but they come and go and it may be unrelated, who knows.
i hope King's better by now, how worrisome. good luck!