Bacterial infection.

[Jay Hemdal]

@Jay Hemdal

So I could possibly be dealing with two independent issues.

One related to an intestinal abnormality or foreign body, or infection of reproductive system.

And a bacterial infection that appears to be affecting the lateral line region of the specimen.

As this is a newly acquired specimen handled during collection with degassing of swim bladder, using a hypodermic needle. Normally, this is inserted at the region of the anus. I would imagine that it’s possible these issues could be correlated from common bacterial infection, originating from needling, your thoughts?

I cannot see the prolapse in the video, but I can see the elongate lesion above the lateral line. this fish is also breathing too fast.

How do you know the fish was vented through the anus? - commercially collected fish are not vented through the anus, they are de-gassed directly through the side of the fish into the swim bladder. If you went in through the anus, you'd have to go through intestines to reach the swim bladder, virtually assuring peritonitis. Venting through the side only hits muscle tissue, so there is less chance of infection.

Jay

 

[ss88]

@Jay Hemdal
Indeed, the respiration rate does seem elevated.
It’s been a few years since I’ve seen degassing in person. But when diving in the Caribbean in Maldives, I’ve always seen it preformed near the anus. Not to say degassing occurred in this manor.

About the best photo I could possibly obtain of the prolapse in the anus.

Whats the best course of action at this moment? As the condition did not improve with Baytril 19mg/gallon or dosage of 25mg/gallon with neomycin sulfate. Should I consider IM Baytril? Or cipro?

I definitely believe there could be some antibiotic resistance occurring here as the importer used nitrofurazone indiscriminately for a short bath. Also their acclamation methods are not best practice.

 

[Jay Hemdal]

@Jay Hemdal
Indeed, the respiration rate does seem elevated.
It’s been a few years since I’ve seen degassing in person. But when diving in the Caribbean in Maldives, I’ve always seen it preformed near the anus. Not to say degassing occurred in this manor.

About the best photo I could possibly obtain of the prolapse in the anus.

Whats the best course of action at this moment? As the condition did not improve with Baytril 19mg/gallon or dosage of 25mg/gallon with neomycin sulfate. Should I consider IM Baytril? Or cipro?

I definitely believe there could be some antibiotic resistance occurring here as the importer used nitrofurazone indiscriminately for a short bath. Also their acclamation methods are not best practice.

O.K., I can see the prolapse now. If the fish was improperly vented, that could be the cause of this I suppose - but extremely difficult to treat. If the rapid breathing is a result of a systemic internal infection, it becomes even more difficult to deal with.

IP (not IM in this case) Baytril would be the best way to proceed. However, that requires substantial handling of the fish that can compound any problems. Additionally, the dose is fairly narrow, and requires that you know the weight of the fish. The typical dose, as per Lewbert is 5 to 10 mg/kg of fish mass every other day for 15 days. Just guessing here, but your fish probably weighs about 70 grams, so about 0.70 mg at the high end of the dose. You will likely need to do a serial dilution to get down to that amount - lots of math involved!

Jay

 

[ss88]

@Jay Hemdal

As always, thank you for the information.

The immersion treatment with baytril 19mg/gallon appears to be noneffective. The skin lesions expanded in size over 48hrs.

Yesterday, as a last attempt prior to treating with injectables, the enclosure received a 75% water change and was dosed at 250mg/gallon with neomycin sulfate. Neoplex (43% active).

I will review at post 24hr treatment with neomycin sulfate 250mg/gallon for condition of lesions. If no progression or improvement, I will proceed with neomycin 250mg/gallon q24h x 10 with 75% water changes at each interval.

Should post 24hrs not show improvement or lesion size or stabilization. I will proceed with IP Baytril at 10mg/kg q48h x 8 and will weigh specimen to confirm dosage on gram scale while submerged.

Beyond IP Baytril not much else can be done?
Nothing comes to mind for me except culturing bacteria.

I will report of the outcome in a week.

P.S. Fortunately the specimen is still excepting food and is active with energy sufficient to show aggression towards my hand inside the enclosure. So perhaps it has the energy sufficient to pull through this.

 

[Jay Hemdal]

@Jay Hemdal

As always, thank you for the information.

The immersion treatment with baytril 19mg/gallon appears to be noneffective. The skin lesions expanded in size over 48hrs.

Yesterday, as a last attempt prior to treating with injectables, the enclosure received a 75% water change and was dosed at 250mg/gallon with neomycin sulfate. Neoplex (43% active).

I will review at post 24hr treatment with neomycin sulfate 250mg/gallon for condition of lesions. If no progression or improvement, I will proceed with neomycin 250mg/gallon q24h x 10 with 75% water changes at each interval.

Should post 24hrs not show improvement or lesion size or stabilization. I will proceed with IP Baytril at 10mg/kg q48h x 8 and will weigh specimen to confirm dosage on gram scale while submerged.

Beyond IP Baytril not much else can be done?
Nothing comes to mind for me except culturing bacteria.

I will report of the outcome in a week.

P.S. Fortunately the specimen is still excepting food and is active with energy sufficient to show aggression towards my hand inside the enclosure. So perhaps it has the energy sufficient to pull through this.

So - “hunt and seek” is what I call trying one medication after another. With antibiotics, that is problematic because they take 3 to 7 days to work. If you change things up before then, they haven’t had a chance to work. A sensitivity study is really needed to know what class of antibiotics is going to be effective….otherwise, we just do our best guess.

The IP Baytril is attractive to me because it stands the best chance of handling internal bacterial issues.

 

[ss88]

Let me recap.

Continued treatment with enrofloxacin 20mg/g 7 day duration with 100% water change at 24hr interval. Ammonia was problematic without a bio filter. Concluded on 3/21/2024.

Symptom regression 3/23/2024.
Started treatment with enrofloxacin IM. 10mg/kg. Specimen weight 318.18grams. Injectable solution was 22.7mg enrofloxacin per ml.
Treatment started at 0.14ml 3/23/24.
total of 7 treatments now at 13 days.

Symptoms improved but lesion are not fully resolved as seen in video, no redness remains. Should I continue treatment for some additional time past full resolution of the lesion?

Fish appears to be swimming with posterior elevation above the horizontal plane. This condition is a post IM treatment.


Injection location as shown in this image with maximum injection depth of around 0.2" with 23 Ga. Smaller gauge would not easily pierce.

 

[ss88]

Its a decent size specimen.

 

[ss88]

I will also add that I’m currently on day 39 of copper treatment. As my quarantine systems for inverts, fish and corals are all in close proximity 1-2 feet distance. I have as a safety measure assumed i need a full 6 weeks of isolation. Cross contamination is highly possible given the proximity. All tanks are at 80F. Livestock acquisition and addition to quarantine zone occurs on day one, no post additions occur.

 

[Jay Hemdal]

I will also add that I’m currently on day 39 of copper treatment. As my quarantine systems for inverts, fish and corals are all in close proximity 1-2 feet distance. I have as a safety measure assumed i need a full 6 weeks of isolation. Cross contamination is highly possible given the proximity. All tanks are at 80F. Livestock acquisition and addition to quarantine zone occurs on day one, no post additions occur.

Which copper are you using? You can stop coppersafe at around 30 days after the last protozoan symptoms were seen, or at 30 days if preventative.

 

[Jay Hemdal]

I will also add that I’m currently on day 39 of copper treatment. As my quarantine systems for inverts, fish and corals are all in close proximity 1-2 feet distance. I have as a safety measure assumed i need a full 6 weeks of isolation. Cross contamination is highly possible given the proximity. All tanks are at 80F. Livestock acquisition and addition to quarantine zone occurs on day one, no post additions occur.

So - the tanks are within a foot of each other? Horizontal, not vertical, right?
I’ve used plastic sheet or even cardboard to stop aerosol dispersal of parasites between nearby tanks….plus cleaning tank tools and my hands between tanks.

 

[Jay Hemdal]

Let me recap.

Continued treatment with enrofloxacin 20mg/g 7 day duration with 100% water change at 24hr interval. Ammonia was problematic without a bio filter. Concluded on 3/21/2024.

Symptom regression 3/23/2024.
Started treatment with enrofloxacin IM. 10mg/kg. Specimen weight 318.18grams. Injectable solution was 22.7mg enrofloxacin per ml.
Treatment started at 0.14ml 3/23/24.
total of 7 treatments now at 13 days.

Symptoms improved but lesion are not fully resolved as seen in video, no redness remains. Should I continue treatment for some additional time past full resolution of the lesion?

Fish appears to be swimming with posterior elevation above the horizontal plane. This condition is a post IM treatment.


Injection location as shown in this image with maximum injection depth of around 0.2" with 23 Ga. Smaller gauge would not easily pierce.

That’s a lot larger fish than I had thought. Fish weights are tricky - as the length increases linearly, the mass increases more geometrically.
The change in swimming stance may indicate an issue with the swim bladder - are you sure you missed that organ with your injections?

 

[ss88]

So - the tanks are within a foot of each other? Horizontal, not vertical, right?
I’ve used plastic sheet or even cardboard to stop aerosol dispersal of parasites between nearby tanks….plus cleaning tank tools and my hands between tanks.

My logic has been just wait 45 days in copper. I use copper power at 2.10-2.25ppm. I'm sure some small cross contamination occurs.

 

[ss88]

I considered the swim bladder as well. But I don’t think I hit it.
The injection site is above spinal region.
Black dot and arrow are location of Injection site.
Red ellipse, this is my understanding of the swim bladders location.

Is there a better injection location to consider to conclude the next few treatments?

Green square is one of the lesions I was treating for.

 

[ss88]

The specimen just seems slightly positively buoyant. He is still accepting food, in fact never refused from day one.

 

[Jay Hemdal]

I considered the swim bladder as well. But I don’t think I hit it.
The injection site is above spinal region.
Black dot and arrow are location of Injection site.
Red ellipse, this is my understanding of the swim bladders location.

Is there a better injection location to consider to conclude the next few treatments?

Green square is one of the lesions I was treating for.

Swim bladder is a bit higher than the ellipse, but lower than the injection site. You could have hit the posterior kidney though.

 

[ss88]

Should I make subsequent injections higher dorsally and posterior or more dorsal and anterior?

 

[Jay Hemdal]

Should I make subsequent injections higher dorsally and posterior or more dorsal and anterior?

Dorsally and anterior, but also alternate sides. However, you've done 7 injections? I would start to wonder if the bacteria may not be sensitive to enro. Lewbert (in Noga) says you can go up to 14 daily injections with this, but that seems like a lot to me.

Just an opinion - external bacterial infections are disruptive to the skin layers. That must damage the blood flow to the area. That in turn, would likely reduce the effectiveness of any injected antibiotic, and allow for continued reinfection from the bacteria in the tank water. For that reason, I always use antibiotic baths in cases where the bacteria is clearly living on the outside of the fish.

Jay

 

[ss88]

@Jay Hemdal

Thanks for all the support with this specimen.
Let me recap the events and current symptoms.

The specimen originally presented with lesions around the lateral line as well as a prolapse of the anus. I suspected improper degassing, but its unknown.

Both of these symptoms resolved with the treatment of Enrofloxacin 20mg/gallon 7 day treatment duration.

Two days post immersion treatment, several lesions reappeared.

Starting on 3/23/24 I commenced with treatment of Enrofloxacin IM at 10mg/kg q48hr x 8.

3/26/24, lesions appeared to be resolving.

4/1/24 I noticed what I thought appeared to be a slight positive buoyancy in swimming behavior.

4/6/24. buoyancy issue remains unchanged or slightly more pronounced. The lesions are mostly resolved and only discoloration remains.

Fairly sure there is a buoyancy issue. The specimen does not remain still at night even after hours of total darkness.

Its day 14 of treatment with Enrofloxacin IM, IMO continuing treatment with Enrofloxacin IM does not seem justified. Most of the information I found on dosage was 5-10mg/kg 48hr q x 5. I deliberately opted for longer treatment duration because of risk of reoccurrence.

So, what are my options at this point?

1) Wait and see if the positive buoyancy issue resolves in a few days or week?

2) Risk degassing the swim bladder. Its been years since I have seen this done in person. This would only provide temporary relief most likely?


From my understanding, this buoyancy issue can be caused from tissue inflammation of the swim bladder preventing natural pressure equalization, is this correct? Normally caused from bacteria? Or in this instance, possible mechanical damage from improper location of injection? I don’t think I hit the swim bladder like you said, possibly kidney but i was above the spinal region by likely 1cm.

On a positive note, the specimen is still actively eating well.

I guess, wait and see what occurs in the next 72hrs, is likely the best course of action.

Concerning bacterial sensitivity testing, I don’t really have access to bacteria antibiotic sensitivity testing here today, although I can procure the materials this week should that be the next course of action.

 

[Jay Hemdal]

@Jay Hemdal

Thanks for all the support with this specimen.
Let me recap the events and current symptoms.

The specimen originally presented with lesions around the lateral line as well as a prolapse of the anus. I suspected improper degassing, but its unknown.

Both of these symptoms resolved with the treatment of Enrofloxacin 20mg/gallon 7 day treatment duration.

Two days post immersion treatment, several lesions reappeared.

Starting on 3/23/24 I commenced with treatment of Enrofloxacin IM at 10mg/kg q48hr x 8.

3/26/24, lesions appeared to be resolving.

4/1/24 I noticed what I thought appeared to be a slight positive buoyancy in swimming behavior.

4/6/24. buoyancy issue remains unchanged or slightly more pronounced. The lesions are mostly resolved and only discoloration remains.

Fairly sure there is a buoyancy issue. The specimen does not remain still at night even after hours of total darkness.

Its day 14 of treatment with Enrofloxacin IM, IMO continuing treatment with Enrofloxacin IM does not seem justified. Most of the information I found on dosage was 5-10mg/kg 48hr q x 5. I deliberately opted for longer treatment duration because of risk of reoccurrence.

So, what are my options at this point?

1) Wait and see if the positive buoyancy issue resolves in a few days or week?

2) Risk degassing the swim bladder. Its been years since I have seen this done in person. This would only provide temporary relief most likely?


From my understanding, this buoyancy issue can be caused from tissue inflammation of the swim bladder preventing natural pressure equalization, is this correct? Normally caused from bacteria? Or in this instance, possible mechanical damage from improper location of injection? I don’t think I hit the swim bladder like you said, possibly kidney but i was above the spinal region by likely 1cm.

On a positive note, the specimen is still actively eating well.

I guess, wait and see what occurs in the next 72hrs, is likely the best course of action.

Concerning bacterial sensitivity testing, I don’t really have access to bacteria antibiotic sensitivity testing here today, although I can procure the materials this week should that be the next course of action.

I would not try de-gassing a buoyant fish. I've done that hundreds of times and have NEVER fully resolved the issue doing that. I even built a pressure chamber that would resolve the issue - until I bled the pressure off then the issue returned. As long as the fish is still eating, I'd not mess with that.

 

[ss88]

@Jay Hemdal thanks for the information.