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View Full Version : Help! - Possible Fish Tuberculosis outbreak



Chris McMahon
Mon Feb 14, 2005, 10:56 PM
I think I might have an outbreak of Fish TB in my main 5x2x2 tank.

Yesterday I noticed one of the adult bristlenoses with several body lesions approximately 10mm in size. At first I though something had attacked it as it looked like several bites had been taken out of it. The lesions are white and look necrotic, ie missing fresh.

Later that day I noticed a Royal Whiptail with a blood red stain on he side of it's body, and blood around the vent. I euthanized the whiptail and put it down to it possibly eating a sliver of glass from a decent broken light over the tank (broken MH light cover due to a splash a few weeks ago).

I tried to remove the Bristlenose at the same time but the tank is well planted and I lost it amongst the plants.

Late last night I did a bit of searching and came across this image:
http://www.fishpalace.org/ttuberculosis_noodles.jpg
It's a perfect match for the stains my Whiptail had. Unfortunately that image is described as "tuberculosis infection, with classic appearance (http://www.fishpalace.org/Disease.html#TB)"

I waited until the early hours 2-3am, in the dark, for most of the fish to go to sleep and managed to get the affected bn into a bucket. It's alive and I'd like to take it to someone who could confirm or deny my suspensions of fish TB.

Can anyone recommend a vet or person who could give me a firm diagnosis of TB or not on the Gold Coast?
Please email me asap if you do. chrismc@bigpond.net.au

Given the lack of treatment for fish TB, it looks like I'll lose everything in the tank if it is present, including 6 discus. Not to mention possible cross contaimination with my other 7 tanks, fully of adult discus pairs.

wyldchyld01
Tue Feb 15, 2005, 02:11 AM
chris,

don't know a vet sorry, but thought i should point out that tb can be contracted from fish so be very very careful, the mycobacteria that causes it is the same in fish as in humans

as last i heard if you fear tb you should sacrifice all fish in the tank and thoroughly disinfect all equipment, substrate, tank, ornaments etc...seriously disinfect and then start from afresh

if you have access to a microscope you can view the tb cysts by taking samples from the gut, gill bladder etc to confirm whether or not it is tb (looking for a small solid yellowy circular fellow)

good luck and here's fingers crossed it's not tb

brenton

leanne31
Tue Feb 15, 2005, 05:36 AM
hi Chris just browsing simplydiscus.com and came up on a section on fish tuberculosis and thought of your post,theres also a lot of links there to you may like to check it out it says you should isolate all sick fish and wear gloves as it can be passed on to humans I hope it helps and good luck Leanne

Chris McMahon
Tue Feb 15, 2005, 06:01 AM
Update: I called several LFS asking for recommendations for vets. No luck. I called a couple of vets looking for referrals but kept getting referred to a vet who moved to Tasmania years previously.

I even tried the RSPCA, who I thought would surely know of someone - nope.

Finally I contacted the Department of Primary Industries and Fisheries (DPI). I managed to get a Dr Roger Chong, who specialised in Fish Health. I packed up the bn in a bucket with a portable air pump, and headed up to Brisbane, roughly a 160km round trip.

Now I have to wait for the results of the autopsy. If the fish was alive (I didn't check before handing it over) I would get a result in a few days to a week. If it was dead, then a culture would need to be made which can take up to 8 weeks, and might not work at all.

There is also ~ $100 fee for the test, which I didn't think too bad as a pathology lab would have been ~$300. Registered primary producers get the service for free - and no, fish breeders aren't covered, I asked.

So that's it. There's a good chance that if it is TB, every fish in the tank is either infected, or a carrier. The tank is my main 5x2x2 display tank with everything from neon tetras to 5" adult discus in it. Maybe $600-800 to restock.

From what the DPI guy said, there's no treatment for TB so there's not much I can do. Tomorrow I'll need to buy new nets, hoses, etc hope that it doesn't spread to my other tanks with the adult discus pairs.

Merrilyn
Tue Feb 15, 2005, 06:42 AM
Chris, this is awful. I hope you find that this is just some bacterial infection, and not TB. We're all keeping our fingers crossed for you.

weird
Tue Feb 15, 2005, 07:02 AM
Ammonia poisoning can cause red streaks to appear on fins of fishes.

Dave76
Tue Feb 15, 2005, 07:02 AM
Sorry to hear about the trouble you are having Chris :(

I recall reading ages ago about some success treating TB with certain antibiotics fed or injected directly into fish - I'm sorry I can't remember where it was tho - I just tried a quick google but couldn't find it - I'll see if I have it saved down in a favourites list somewhere when I get home tonight.

Regards

Dave

Aurora
Tue Feb 15, 2005, 07:11 AM
Gee Chris, you really dont have much luck do you?

First one of your tanks breaks destroying carpet, power boards and a computer. Now a potential TB outbreak might wipe out all your fish.

The gods are certainly putting obstacles in your path :(

Chris McMahon
Tue Feb 15, 2005, 07:26 AM
Chris, this is awful. I hope you find that this is just some bacterial infection, and not TB. We're all keeping our fingers crossed for you.Thanks.


Ammonia poisoning can cause red streaks to appear on fins of fishes.Unfortunately the large sections of missing fresh is a little harder to explain. It looks like something took several large bits out of it. While this could indeed be true, I find it hard to believe a otherwise healthy bn would just site there while a clown loach or rainbow had a meal of its back.


I recall reading ages ago about some success treating TB with certain antibiotics fed or injected directly into fish - I'm sorry I can't remember where it was tho - I just tried a quick google but couldn't find it - I'll see if I have it saved down in a favourites list somewhere when I get home tonight.I found something like that myself. Seems to be a one off. The general consensus is the fish TB is untreatable.


Gee Chris, you really dont have much luck do you?

First one of your tanks breaks destroying carpet, power boards and a computer. Now a potential TB outbreak might wipe out all your fish.

The gods are certainly putting obstacles in your path :(You forgot the fly spray mass die off. Sometimes I come close to giving this hobby up. I've had more bad luck in 10 months than most people have in a decade. Then a few weeks pass and I see some new discus in a shop and can't help myself.

While the financial loss of replacing equipment and stock isn't insignificant, I hate the suffering I'm putting these fish though more. I hate it when a fish dies, even a single platy. To lose the discus, rainbows, platies, neons, bns, whiptails, corys and clowns in the main tank would be heart breaking.

I wish it was just a simple matter of someone saying buy product X and everything will be ok.

kalebjarrod
Tue Feb 15, 2005, 09:06 AM
i wish i could have helped you but alas i have as many vet fish contact as you :cry:

wyldchyld01
Wed Feb 16, 2005, 04:14 AM
chris,

sorry to hear all of the fish have the infection,

sent you a pm

brenton

Merrilyn
Mon Feb 21, 2005, 03:27 AM
Chris, have you had any results from the tests back yet? We're all thinking of ya mate.

Chris McMahon
Mon Feb 21, 2005, 01:07 PM
Chris, have you had any results from the tests back yet? We're all thinking of ya mate.Thanks ladyred.

I got the results of the necropsy last Friday.


History
Private aquarium with a community of tropical ornamental fish. Royal whip tail (catfish) culled which had skin red blood spots and bleeding at the vent. Bristle nose corydora (catfish) with circular skin ulcers. Discus appear sick following. Owner concerned about fish TB or mycobacteriosis.

Necropsy
1 bristle nose corydora submitted live for diagnosis. Length 10 cm. 3 large skin ulcers on the head /nose and sides of the pectoral area. Nose ulcer bleeding. Wet mount – gills normal, skin lesion showed moderate amounts of Saprolegnia type fungal hyphae. No obvious internal lesions.

Histology
Liver – some fat deposition. Spleen – mild congsetion. Muscle/skin – inflammation and localised necrosis of dermis and muscle fibres. Kidney – mild calcium deposition in the renal tubule lumens.

Bacteriology
Skin lesion – mixed culture, no significant isolates.

Kidney – no isolates.

Diagnosis
There is no evidence of mycobacteriosis in the fish. The skin lesions are associated with Saprolegnia fungal infection. This is commonly related to organically enriched water/tank environment from either the build up of fish feces and feed wastes or high density of fish and inadequate water exchange or filtration. The calcium deposition in the kidney is a symptom of chronic exposure to elevated levels of carbon dioxide in the water.

Thankfully it isn't fish TB. I was surprised at the "water exchange or filtration" result. I do a weekly sand vacuum on the tank, and do a single 45-50% water chance once per week. I would have thought that as aquariums go, that's more than the average person does.

The high levels of CO2 also surprised me as I don't add any CO2 to the tank, although it is fairly heavily planted. I'd assume then that the high levels of CO2 are from either fish respiration or plant respiration or both.

Management Options

1. Improve the tank environment – regular removal of organic waste build up in the gravel bed. Perform regular water exchanges. Reduce stocking density to control carbon dioxide levels in the water. The more fish in the tank, the higher the production of carbon dioxide gas. Maintain good aeration and avoid excessive feeding.I've doubled my maintenance on the tank, going from weekly 50% water changes to bi-weekly, with vacuuming at the same time.

2. Salt at 3-5 parts per thousand (ppt) gradually added to the tank as a prolonged immersion to inhibit the spread of Saprolegnia. Use lower dosage of salt for sensitive species such as catfish and discus. Salt is useful to reduce the osmotic stress of fish that have ulcerated wounds. If you are concerned about salt on the discus and catfish – you may separate these fish and treat them at lower doses. Using 3-5 ppt salt is to treat the tank against the fungus. Lower doses may not be effective against the fungus. Note : 3 ppt salt = 3 grams of salt /litre of water. Seawater contains 35 ppt salt. 3% salt = 3 g/100 ml = 30 g/L = 30 ppt = nearly seawater. 3% salt is not the same at 3 ppt salt. Use a hydrometer to accurately measure the salinity of the tank so that the salt level is maintained to inhibit the fungus.I got preliminary results within 24 hours of dropping the specimen off. At the time it was suggested that I add the salt. I queried the level of salt with a LFS. Normally the maximum level of salt I put in my tanks is 1 teaspoon per 10 litres. 3ppt is 30g per 10 litres, which seems very high to me. For the affected tank (460L) this works out to 1.38kg of salt!! Opinions?

3. The long term control of fungus is in minimising the organic matter in the tank. Treatment with other chemicals such as formaldehyde (formalin), malachite green are usually temporary measures, as the fungus will recur if the hygiene of the tank environment is suboptimal and high stocking densities are maintained.I talked over the fungus diagnosis with the LFS and they recommended a 1/2 rate does of 3-day white spot cure (active ingredients malachite green and formaldehyde) to control the fungus. I asked the lab what they thought of this as a possible cure.

4. Both formalin and malachite green are potentially toxic to fish and formalin will damage the biofiltration. Formalin should not be used in fish with open wounds. Note : malachite green is carcinogenic (has a risk of causing cancer in people when overexposed to it).

Am I over stocking?

The tank is a 5x2x2. Nominal capacity 550L, actual capacity (taking into account 3D background, sand, height of water vs tank height etc) 460L.

Filtration is 2x Pro Aqua CF-1500 canister running in series (rated 1500L per hour, up to 600L tank - each)

Ammonia 0ppm
Nitrite 0ppm
Nitrate <10ppm

Stock list:
1x adult 12cm discus (Red/White)
3x juvenile 7cm discus (Blue Diamonds)
8x adult 6cm congo tetra
10x adult 8cm rainbows
3x 7cm SAEs
5x 10cm Royal Whiptails
4x 10cm Clown Loaches
10x 3cm platies
6x adult 10cm bristlenoses

I lost on of my 7cm juvenile discus on Saturday. It had turned black (it was a Blue Diamond) in the last few days (it had been dark for a couple of weeks - alternating between looking dark and looking normal) and was fairly thin. Two of remaining Blue Diamonds are darker than normal and looking sick still. I'm worried about losing them too.

Sunday I lost an adult Congo tetra. It appeared to "puff up", sort of like bloat but evenly over the entire body, it swelled maybe 10-15% in size.

So far I've added 1 teaspoon of salt /10L. Dosed 1/2 rate whitespot and have been treating the tank with Pimafix anti-fungal. Apart from 2 dark BD discus, all other fish appear healthy.

I'm still concerned that I might have something other than fungus in the tank. Over the last couple of months I've tried:
-Melafix
-Pimafix
-Tri-sulfa at 1tab/40L and 1tab/20L
-Metronidazole