Why higher temps AFTER metro. treatment?

[discusdave]

I recently completed the Metronidazole treatment on some new discus and was wondering why we need to keep the temp at 92 or so for a week after the treatment is over? Does it help the fish or hurt the hexamita or something? Thanks.

Dave

[Barb Newell]

Hi Dave, some do that. My guess is that it's to encourage them to start eating again.

Barb

[Jeckel]

Quoting from an article by Dr. Gottfried Schubert in the book "All About Discus" by Herbert Axelrod (pp. 90-91):
"At the Zoological Institute, Hohenheim University, a large number of discus were kept for study of this condition (Spironucleus). I touched the water one day while feeding and discovered that the temperature had risen because of a thermostatic malfunction. Corrections were made and I thought no more about the occurrence until I killed a fish a few days later to show the flagellates to a colleague. There were none, nor were there any in two other fishes that were dissected, whereas all had previously been heavily infested.
"...It was found that discus could endure 104 degrees for only a few hours but tolerated 100 degrees for several days and were comfortable at 95 degrees temperature. The parasites could not survive longer than three days at 100 degrees, and at the safer 95 degree temperature none persisted at the end of a week."

I think Spironucleus is usually responsible for the symptoms we generically attribute to Hexamita in discus, and this passage indicates that the flagellated protozoa are killed by high temperatures. Also, heat tends to accelerate the effects of medication by speeding up the pathogens' metabolism. Although 92 degrees seems to be the standard for "hexamita" treatment, some references recommend 96. I've kept discus at 96 degrees for over a week with no ill effects.