Most of the time. Cant when the fish you are buying are in the bottom of a black AP tub or when ordering fingerlings on line, etc.
Bringing something out of the river has the odd risk but generally its exactly as Johnno said worms/flukes which is why I bothered to mention praziquantel and kusuri in my previous post. Johnno referenced another product Internal Parasite Clear... does the same thing.
When you pull in a fish you dont know 100% about its state of health but you look for a few things: obvious skin/scale/fin growths or damage, eyes are clear and seem normal, belly looks full... its obviously eating if it smashed your bait or lure. Bream or other estuarine species from the swan arent going to have ich...
Fish are pretty safe from the river normally.
Edited by malawiman85, 27 January 2016 - 07:53 AM.