Unfortunately treatment for TB seems to be either ineffective or not
cost-effective although there must be some situations with very expensive
or hard to replace fish where it would be worth trying.
One of the problems would be getting the drug into the fish in sufficient
doses to be effective as it would have to be swallowed or injected I think.
Sick fish don't usually eat as well as well ones. In human medicine the
treatment usually needs to be administered for a very long time to be sure
of preventing recurrences also.
Regards,
Bruce.
Bruce Hansen, ANGFA, caring for our aquatic ecosystems.
Please visit us at http://www.ozemail.com.au/~fisher/angfa.htm
----------
> From: Adrian R. Tappin <atappin at ecn.net.au>
> To: rainbowfish at pcug.org.au
> Subject: [RML] Blackhead disease update
> Date: Saturday, 28 February 1998 16:43
>
> I thought that I would update you all on the pathology results of some
fish
> I had examined...
>
> Six specimens of Melanotaenia oktediensis were examined by our resident
> Fishician, Dr. Stephen Pyecroft. All six specimens had what I call
> "Blackhead Disease" in varying degrees. This disease presents itself as a
> black darkening of one side of the head only. Two of specimens also had
> small skin eruptions (pimples) on one side of the body and one also
showed
> the darkening skin colouration along one side of the posterior portion of
> its body. This was the first specimen that I've seen with body
> discolouration. In my experience I've only ever seen just the head
> discolouration.
>
> The most severely affected fish would swim with their head up and tail
down
> and showed an increased respiratory rate. This disease (blackhead) seems
to
> be fairly common among rainbowfishes as I have seen it often and many
other
> hobbyists have also spoken to me about this disease. It also seems to be
> particularly prevalent among Goyder River trifasciata.
>
> Stephen found that most of the fish had enlarged kidneys, which had a
> granulated pale colour and protruded beyond their normal position.
> Granulomas were also present in the spleens and around abdominal organs.
> Acid fast (Ziel-Neilson) stains were preformed on impression smears from
> most of the affected organs and the presence of acid fast bacteria was
> confirmed.
>
> The Diagnose: Disseminated granulomous inflammation - nephritis,
hepatitis
> and peritonitis.
>
> Stephen commented "As we have discussed before, the dark areas on the
skin
> are most likely due to a malfunctioning in either the pigment cells or
the
> nerves that control the pigment cells in that area of the skin. The
findings
> of a generalised infection with Mycobacteria sp. would be suggestive that
> the localisation of the dark pigmentation is due to the formation of
local
> abscesses which are then causing the expression of the major clinical
sign.
> Most of the cases of "blackhead syndrome" in rainbow fish that I have
> investigated have had a primary infection with Mycobacteria spp. There
may
> be other primary causes of this distinct clinical sign but in these fish
it
> was piscine TB.
>
> Adrian.
> ...............................................................
> Adrian R. Tappin
> "Home of the Rainbowfish"
> http://www.ecn.net.au/~atappin/home.htm
> ...............................................................
>