Maggot like beasts on dead Achilles in QT

[Deinonych]

Here's an example of what happens when it is dosed incorrectly: http://www.advancedaquarist.com/blo...ally-kills-100-reef-fish-with-fluke-treatment

 

[ThRoewer]

Dylox is truly a last resort. It's extremely nasty stuff, and I would hesitate to use it. Sometimes the cure is worse than the disease.

There are quite a few monoganeans that tolerate Praziquantel just fine (see list in Noga). For some of those Trichlorfon is the only effective treatment, while others can be killed off with hyposalinity (= salinities below 15 ppt).

These guys are not ich or velvet where you are dealing with strains of a specific parasite species, but rather a whole class of parasites with several sub classes, at least 50 genera and thousands of species. Some species only live in freshwater, some only in saltwater and some in both.
As diverse as the class are also the required treatments.

My future approach will be to start with hyposalinity.
If that doesn't help I will add PraziPro to the tank. The lower salinity should help to keep enough oxygen in the tank for the fish.
If that still doesn't help ...