In reply to Shrimpy ……. Depends on whether or not one has a suitable quarantine tank. One with algae growth and periphyton, well cycled for at least a month, preferably with thriving plants. And don’t pretreat.

Elise ….. After four weeks the tank should be just fine. All pathogens should have died down to non-pathogenic levels. Just make sure you are prepared with a shotgun approach of medications in case history repeats itself.

In reply to Mark B …. 1, The epidemiology of capillaria is not that simple. If you examine the feces in a tank you will fined easily 50% of the fish have capillaria eggs. I only treat when fish start exhibiting symptoms such as not eating and hollow belly.

2, The worms can only feed in the belly of the fish. So they die outside the belly even if the paralyzing medication has worn off.

Here in the “Quarantine Tanks” chapter I see “…“deworming” the new arrivals with Fenbendazole (or levamisole) and praziquantel in the food for worms for their remaining stay in the quarantine aquarium. …Deworming medications only need to be fed once every two weeks for the whole quarantine period. Deworming typically takes at least six weeks to be effective.”

Question 1: if I put new fish into my quarantine tank that (unbeknownst to me) have capillaria, and feed them Fenben and Prazi prophylactically, would I be putting off the inevitable to not dose at the stronger/longer capillaria regimen?

Question 2: Fenben and Levamisole paralyze the jaws of the worms and they lose their grip and pass out of the fish, where instructions tell us to vacuum them out. Inevitably, some worms are lost in the filter or substrate. No one says what happens to them. Are their jaws paralyzed permanently? And if not, would it make sense to add Levamisole (the only water-soluble anthelmintic) to the water to keep their jaws paralyzed till they starve?

Thank you, Mark B

Fish can slow down their eating or even stop eating for a variety of reasons. Necropsies on dead fish with “no eating” or “food spitting” show the following incidence:

40% have “hexamita” (“internal parasites”, treat with metronidazole and Epsom salts)
30% have capillaria (“worms”, treat with Fenbendazole or Levamasole)
20% have bacterial infections (treat with antibiotic)
10% have no apparent pathogen

Other symptoms such as hollow belly and bloat also have this “multifactorial etiology” and, like “not eating”, need to be treated with what is basically a shotgun approach with multiple medications. Treatment is difficult and typically involves pipetting or shallow baths. More about it can be found at the following article: http://tankstartguide.com/index.php/11-15-fish-not-eating/

In reply to Howard ….. Only thing to do in Canada is to use left over human antibiotics.