Low dose chloroquine phosphate

[Halal Hotdog]

I have received a new batch of tangs and they are currently in QT. I QT all my fish with chloroquine phosphate. When I introduce tangs at higher level of CP ~ 60-80mg/gallon I notice significant appetite suppression. Even at 40 mg/gallon I have noticed lethargic behavior. This time around I put my fish into QT and the initial dose of cp is 16-18mg/gallon. My question is why is 40mg/gallon the standard recommended dose? Has anyone had experience running fish through lower doses? The fish are hitting the 48 hour mark and almost all of them are eating well with little to no signs of lethargy. I am debating about raising the concentration up to 40mg/gallon.

 

[Halal Hotdog]

@Humblefish any idea?

 

[Halal Hotdog]

Does anyone know where that 40mg/gallon recommendation come from?

 

[Halal Hotdog]

@4FordFamily @HotRocks any thoughts on this.

 

[4FordFamily]

40mg has failed me, we use 60mg minimum. I’d use 80. Appetite suppression for a few days isn’t abnormal, but it’s more likely that ammonia is also contributing. Prime is your friend for this.

 

[robert]

My question would be, In the absence of ich, velvet or something else specific, why would you subject your fish to CP? Chronic exposure likely is not without consequence to the fish. Other than appetite suppression, I might expect retinal damage as a possibility.

The range of 16-18mg would seem to be much closer to the dose given in humans to prophylactically suppress malaria.

 

[Halal Hotdog]

40mg has failed me, we use 60mg minimum. I’d use 80. Appetite suppression for a few days isn’t abnormal, but it’s more likely that ammonia is also contributing. Prime is your friend for this.

Wow surprised 40mg failed you but based on your posts you have quarantined a TON of fish. I imagine you absolutely had pharmaceutical quality. Which parasite made it through?

 

[Halal Hotdog]

My question would be, In the absence of ich, velvet or something else specific, why would you subject your fish to CP? Chronic exposure likely is not without consequence to the fish. Other than appetite suppression, I might expect retinal damage as a possibility.

The issue is introducing a fish with a subclinical infection to my DT. Observing in QT has never worked for me, and I find CP to be one of the mildest treatments for the largest spectrum of parasites. I have a very high regard for my animals and losing them due to something that could have been prevented is unacceptable.

In terms of retinal damage, I have no clue. This is the first I am reading about it. I wouldn't consider 2-4 weeks to be chronic exposure

 

[4FordFamily]

Wow surprised 40mg failed you but based on your posts you have quarantined a TON of fish. I imagine you absolutely had pharmaceutical quality. Which parasite made it through?

Velvet. The issue with CP is there are so many unknowns. Light, biofilter, organics (life in general), and a myriad of other things absorb it, we don’t know how much.

More testing is needed.

We’ve used it successfully, however.

 

[Halal Hotdog]

Velvet. The issue with CP is there are so many unknowns. Light, biofilter, organics (life in general), and a myriad of other things absorb it, we don’t know how much.

More testing is needed.

We’ve used it successfully, however.

That's terrible. How long was it in CP for? Can you provide more into on the situation? Definitely going to bump up CP concentration tomorrow with water change.

 

[4FordFamily]

That's terrible. How long was it in CP for? Can you provide more into on the situation? Definitely going to bump up CP concentration tomorrow with water change.

Honestly too many factors to be sure but it was dozens of fish not one. Very bad, happened too quick to save them in observation. A bad bad day.

We suspect that the poly in the filter cartridges removed some, so that is another factor. Although recently we had velvet survive 1.75 PPM copper so there are a lot of questions out there. Perhaps that CP batch isn’t what failed, perhaps it was copper. We had some fish in CP others in Copper and when we combined them in to a giant 125 observation tank everything grenade when velvet came swinging back.

We assumed it CP but we just had velvet make it through on copper at 1.75PPM. 2.0 next.

 

[Gareth elliott]

Could try a mixture of seachem’s entice and selcon or fish oil.

Add the entice to the water itself for hanging nori grazing and the selcon or fish oil for the more regular feedings.

 

[robert]

10mg/liter is the dose I seen used and recommended by various sources for ornamental fish. Usually as an initial dose with a followup after seven days if necessary. Bio accumulation is an issue as is an increase in toxicity at higher pH, not to mention that a resistance to the drug has been observed in some targets.

Something to watch for...

"Chloroquine retinopathy was produced experimentally in the eye of the albino corydoras (one of the tropical fish) by daily administration of chloroquine (0.1 mg per os). The enucleated eyes were examined from the 14th day to 3 months after the beginning of drug administration under light and electron microscopy. The first change of retina was the appearance of membraneous cytoplasmic body (MCB) in the cytoplasm of ganglion, amacrine, bipolar and horizontal cells...."

Just be vigilant...It might be best to treat in reduced light and watch for photo sensitivity if your going to exceed 10mg liter for any length of time.

Quite apart from this discussion - did you know that brine shrip hatchlings eat the daylights out of Amyloodinium ocellatum? I mean they have a serious appetite for the stuff...

 

[Halal Hotdog]

Honestly too many factors to be sure but it was dozens of fish not one. Very bad, happened too quick to save them in observation. A bad bad day.

We suspect that the poly in the filter cartridges removed some, so that is another factor. Although recently we had velvet survive 1.75 PPM copper so there are a lot of questions out there. Perhaps that CP batch isn’t what failed, perhaps it was copper. We had some fish in CP others in Copper and when we combined them in to a giant 125 observation tank everything grenade when velvet came swinging back.

We assumed it CP but we just had velvet make it through on copper at 1.75PPM. 2.0 next.

That does sound like a terrible day. Will be raising the concentration today to 60mg/gal and will feed heavy before the transition.

10mg/liter is the dose I seen used and recommended by various sources for ornamental fish. Usually as an initial dose with a followup after seven days if necessary. Bio accumulation is an issue as is an increase in toxicity at higher pH, not to mention that a resistance to the drug has been observed in some targets.

Something to watch for...

"Chloroquine retinopathy was produced experimentally in the eye of the albino corydoras (one of the tropical fish) by daily administration of chloroquine (0.1 mg per os). The enucleated eyes were examined from the 14th day to 3 months after the beginning of drug administration under light and electron microscopy. The first change of retina was the appearance of membraneous cytoplasmic body (MCB) in the cytoplasm of ganglion, amacrine, bipolar and horizontal cells...."

Just be vigilant...It might be best to treat in reduced light and watch for photo sensitivity if your going to exceed 10mg liter for any length of time.

Quite apart from this discussion - did you know that brine shrip hatchlings eat the daylights out of Amyloodinium ocellatum? I mean they have a serious appetite for the stuff...

Will definitely watch out for any unusual eye sensitivity that develops.

Wow had no idea brine shrimp had an appetite for parasites. Can you provide more info on this? Is there an article I can read that discusses further?

 

[robert]

"Wow had no idea brine shrimp had an appetite for parasites. Can you provide more info on this? Is there an article I can read that discusses further?"

I give links here:
https://www.reef2reef.com/threads/bioremediation-can-brine-shrimp-stop-velvet.578380/#post-5893283