1st complete prazipro treatment

Hello all so I have a 55 gallon freshwater room temp. tank. The tank has been cycled and everything has been fine water stays around 75-77 and all specs have been fine. I have a 6" bluegill is infected with skin and gill flukes(hes a wild fish.) I have been treating with prazipro and did a full 7 day treatment his symptoms have gone down. My question is that he still does a slight "cough" motion but does not shake or "cough" violently anymore, is this a reflex from being infected for so long? I plan to do a follow up treatment in 3 days. My second question is I also have a gold gourami(gets along with the bluegill verywell no agression) he seems to have a black mark on one of his pectoral fins. I cannot tell if it is part of his black and gold pattern or if it is something to worry about. The pectoral fin also is also a little bit red at the base and there are some slight redness on the fin. im not shure if this came with the fish when i bought it from the LFS but he seems to eat find and is doing very well besides this.

yes it is possible, I have school all day till later so it will probably happen tommorro. As for the temp. the bluegill came out of a warm lake so im not that worried about high temp. Although i was a bit concerned about the gourami but from what i gathered gouramis are fine for 73+. He had a very very long aclamation time so not to stress him either. Both fish eat and act healthy(except for 2 things listed above.) I believe he has gill and skin flukes because i would see him shaking his head violently and "coughing" violently 2. He would also shake his body and fins. his fins were clamped until i started doing prazi treatments and salt baths.