Re:Parasites/using the WRONG products!

Pete Giwojna

Dear fishfinder:

Yikes — I’m very sorry to hear about the unfortunate circumstances that led to the demise of your seahorses! You have all of my condolences for the tragic events that claimed the lives of your seahorses.

I am not familiar with Kordon’s Ick Attack so I cannot comment on the safety or efficacy of the product. But I can tell you that seahorses typically tolerate formalin baths or prolonged immersion in formalin at the typical therapeutic dosages without any problems, as we will discuss later in this post, and that it may have been the ammonia spikes that occurred which ultimately caused the death of the seahorses. A spike in the ammonia or nitrite levels in the aquarium can kill seahorses quickly via asphyxiation, under certain circumstances, and you should be aware of the symptoms of ammonia poisoning and nitrite toxicity for future reference. (Yes, it is quite possible that the ingredients in the Ick Attack had an adverse impact the nitrifying bacteria in the aquarium and caused the spike in the ammonia levels.)

The most obvious symptoms of ammonia poisoning and nitrite toxicity are a loss of equilibrium, hyperexcitability, increased respiration and oxygen uptake, and increased heart rate. At extreme ammonia/nitrite levels, fish may experience convulsions, coma, and death. Seahorses exposed to less extreme ammonia/nitrite levels will struggle to breathe. They will be lethargic and exhibit rapid respiration. They may appear disoriented, periodically detaching from their hitching posts only to sink to the bottom.

Ammonia poisoning and nitrite toxicity are completely reversible providing the seahorses weren’t exposed to toxic levels for too long, and the best first aid you can provide for ammonia/nitrite poisoning is to immediately transfer the seahorses into clean, well-aerated saltwater with zero ammonia and zero nitrite.

Exposure to moderate levels of ammonia and nitrite, or high levels of nitrates, can change the normal hemoglobin in the seahorse’s blood stream to a form (i.e., methhemoglobin) that is no longer able to transport oxygen. If this becomes severe enough, it will leave the affected seahorse starved for oxygen, which makes it very weak and fatigued. As a result, the affected seahorses may detach themselves from their hitching posts periodically and rest on the bottom, unable to exert themselves in their weakened condition. As you can imagine, being deprived of oxygen really wipes them out in terms of loss of energy and stamina. And it also results in respiratory distress, and rapid, labored breathing as they try to oxygenate themselves and compensate for the lack of normal hemoglobin.

A rise in ammonia or nitrite levels is especially dangerous any time you are using formalin because the formalin basically consumes oxygen and therefore reduces the dissolved oxygen levels in the aquarium. So a spike in the ammonia or nitrite levels that changed some of the normal hemoglobin in the seahorse’s blood stream to methhemoglobin at the same time the formalin was decreasing the dissolved oxygen levels in the aquarium may simply have asphyxiated the seahorses.

Seahorses are more vulnerable to low O2 levels than most fishes because of their primitive gills. Unlike most teleost (bony) fishes, which have their gills arranged in sheaves like the pages of a book, seahorses have rudimentary gill arches with small powder-puff type gill filaments. Seahorses are said to have "tufted" gills because they appear to be hemispherical clumps of tissue on stems. Their unique, lobed gill filaments (lophobranchs) are arranged in grape-like clusters and have fewer lamellae than other teleost fishes. Because of the difference in the structure and efficiency of their gills, seahorse are unsually vulnernable to hypoxia when CO2 levels are high and/or O2 levels are low.

Your instincts were good and you did very well to check the ammonia levels and perform immediate water changes as soon as you noticed that the seahorses were in distress, but the damage may have already been done; if a significant proportion of the hemoglobin in the seahorses’ bloodstream had been converted to methhemoglobin, and was therefore unable to transport oxygen at all, the seahorses may have been unable to recover even though the water quality was improving and the ammonia levels were dropping again.

One of the properties of methylene blue is that it can reverse this process and convert the methhemoglobin in the red blood cells back into normal hemoglobin, which can then pick up and transport oxygen again as usual. That’s why it is so helpful in relieving shipping stress and treating ammonia exposure and nitrite poisoning. For this reason, you may want to pick up some methylene blue at your local fish store and keep it on hand in case it is ever needed (the Kordon brand of methylene blue is best, in my opinion).

In the future, fishfinder, if you feel it is advisable to treat your seahorses for external parasites prophylactically, a freshwater dip or a formalin bath are good ways to cleanse them of ectoparasites, and praziquantel is a very safe medication that can also be used to eradicate external and internal parasites in seahorses. Here are some instructions for performing formalin baths and freshwater dips safely:

Formalin Baths

Formalin (HCHO) is basically a 37% solution of formaldehyde and water. It is a potent external fungicide, external protozoacide, and antiparasitic, and is thus an effective medication for eradicating external parasites, treating fungal lesions, and reducing the swelling from such infections. It is a wonder drug for treating cases of Popeye caused by trematodes, and also eradicates external nematodes.

In my experience, provided it is administered properly, seahorses tolerate treatment with formalin very well at therapeutic dosages. For a long term bath the correct dose is 15 to 25 mg/L. [Note: 25 mg/L equals 1 ml (cc) of 37% formalin per 10 gallons of water.] This is done every other day for 3 treatments.

For a short term bath (dip) the correct dose is 250 mg/L. This would equal 1 ml (cc) of 37% formalin per 1 gallon of water. This should be for about 45 minutes to 1 hour. In my opinion, formalin is a safe, effective treatment for parasitic infections in seahorses providing you don’t exceed these dosages and observe the following precautions for administering the medication properly:

Many commercial formalin products are readily available to hobbyists, such as Kordon’s Formalin 3, Formalin-F sold by Natchez Animal Supply, and Paracide-F, sold by Argent go to top Chemical Laboratories. Or whatever brand of formalin is available at your fish store should work fine, Pam.

A formalin bath simply involves immersing the seahorse in a container of saltwater which contains the proper dosage of formalin for a period of 30-60 minutes before transferring it to your hospital tank. Include a hitching post of some sort in the container and follow these instructions: place the fish in a three-gallon bucket or a similar clean, inert container containing precisely one gallon of siphoned, aerated tank water. Medicate the bucket of water with with the appropriate amount of formalin for a concentrated bath according to the directions on the label. Place an airstone in the bucket and leave the fish in the bath for 30 minutes. If at any time the fish becomes listless, exhausted or loses its balance, immediately place the fish in clean, untreated water in your hospital tank.

I want you to be aware of these precautions when administering the formalin bath:
Formalin has limited shelf life and degrades to the highly toxic substance paraformaldehyde (identified as a white precipitate on the bottom of the solution); avoid using any formalin product which has such a precipitate at the bottom of the bottle.
Formalin basically consumes oxygen so vigorous aeration must be provided during treatment.
Time the bath closely and never exceed one hour of chemical exposure at this concentration.
Observe the seahorse closely during the bath at all times, and it show signs of distress before the allotted time has elapsed, remove it from the treatment immediately.

If you can obtain Formalin 3 from Kordon at your LFS, Liz, these are the instructions you should follow for your formalin dip:

(a) To a clean, non-metallic container (i.e., a plastic bucket), add one or more gallons of fresh tap water treated with Kordon’s AmQuel . For marine fish use freshly prepared saltwater adjusted to the same specific gravity (or salinity) as in the original tank. Make sure the temperature in the container is identical to that in the aquarium
(b) Add 1 teaspoons of Formalin·3. This produces a concentration of 100 ppm. formaldehyde.
(c) Agitate the solution with an airstone and adjust for a moderately strong flow of air.
(d) Remove the fishes to be treated and deposit them in the container for a treatment period of not more than 50 minutes. Immediately after the treatment period, or if signs of distress are noted, remove the fishes to a previously prepared recovery tank. The fishes may be returned to their original tank, but the presence of the original disease-causing agents in the tank water may result in a reoccurrence of the disease condition.
(e) Observe recovering fishes. Make sure that tankmates do not molest them during recovery.
(f) Repeat treatment as needed, every week. Each treatment is very stressful to the treated fishes. Do not reuse the dip solution.

For additional information on treating fishes with Formalin 3 by Kordon, see the following web page:

Click here: KPD-54 Formalin-3

If you get another brand of formalin, just follow the instructions that it comes with for a concentrated bath or dip (not prolonged immersion or a long-term bath) or follow the following directions, courtesy of Ann at the org:

FORMALIN Short-Term BATH Dosage and Preparation Instructions
Active Ingredient: 37% Formaldehyde
Indication: external parasites
Brand Names: Formalin, Formalin-MS
1. Do NOT use Formalin that has a white residue at the bottom of the bottle. White residue
indicates the presence of Paraformaldehyde which is very toxic.
2. "Formalin 3" by Kordon contains only 3% Formaldehyde. Dosing instructions will need to be modified if using this product.
• Fill a small tank with aged, aerated, dechlorinated marine water. Match the pH, temperature, and salinity to that of the tank the Seahorse is currently in.
• Add an artifical hitch and 1-2 vigorously bubbling airlines. Formalin reduces dissolved O2 so heavy aeration is required.
• Add 1ml/cc of Formalin per one gallon (3.8 liters) of tank water. Allow several minutes for the Formalin to disperse.
• Place the Seahorse into the dip water for 45-60 minutes unless it is showing signs of an adverse reaction. If the Seahorse cannot tolerate the Formalin dip, immediately move it back to the hospital tank.
• Observe the Seahorse for 24hrs for signs of improvement.

Likewise, here are the instructions for performing a freshwater dip.

Freshwater Dips

A freshwater dip is simply immersing your seahorse in pure, detoxified freshwater that’s been preadjusted to the same temp and pH as the water the seahorse is accustomed to, for a period of at least 10 minutes (Giwojna, Dec. 2003). It doesn’t harm them — seahorses typically tolerate freshwater dips exceptionally well and a 10-minute dip should be perfectly safe. Freshwater dips are effective because marine fish tolerate the immersion in freshwater far better than the external parasites they play host to; the change in osmotic pressure kills or incapacitates such microorganisms within 7-8 minutes (Giwojna, Dec. 2003). A minimum dip, if the fish seems to be doing fine, is therefore 8 minutes. Include some sort of hitching post in the dipping container and shoot for the full 10 minutes with your seahorses (Giwojna, Dec. 2003).

If you will be using tap water for the freshwater dip, be sure to dechlorinate it beforehand. This can be accomplished usually one of the commercial dechlorinators, which typically include sodium thiosulfate and perhaps a chloramine remover as well, or by aerating the tap water for at least 24 hours to dissipate the chlorine (Giwojna, Dec. 2003).

If you dechlorinate the dip water with a sodium thiosulfate product, be sure to use an airstone to aerate it for at least one hour before administering the dip. This is because the sodium thiosulfate depletes the water of oxygen and the dip water must therefore be oxygenated before its suitable for your seahorse(s). Regardless of how you detoxify the freshwater for the dip, it’s important to aerate the water in the dipping container well beforehand to increase the level of dissolved oxygen in the water. Many hobbyists leave the airstone in the dipping container throughout the procedure.

Adjusting the pH of the water in the dipping container so that it matches the pH of the water in the aquarium is a crucial step. Ordinary baking soda (sodium bicarbonate) will suffice for raising the pH of the water. If there is too much of a difference in the pH, there is a possibility the seahorse could go into shock during the dipping procedure. Preadjusting the pH will prevent that from happening. If you will are unsure about your ability to accurately adjust the pH in the dipping container, avoid this procedure altogether or be prepared to monitor the seahorse very carefully or shorten the duration of the tip to no more than about 4 minutes.

Observe the horse closely during the dip. You may see some immediate signs of distress or shock. Sometimes the horse will immediately lie on its side on the bottom. That’s a fairly common reaction — normal and to be expected, rather than a cause for concern, so don’t be alarmed if this happens. Just nudge or tap the seahorse gently with your finger if it lies down on its side. Normally, the seahorse will respond to the slight nudge by righting itself again and calm down for the duration of the dip. However, if it does not respond, stop the treatment.

Most seahorses tolerate the treatment well and experience no problems, but if you see continued signs of distress — twitching, thrashing around etc. — stop the treatment.

After you have completed the dip and returned the seahorses to the aquarium, save the dip water and examine it closely for any sign of parasites. The change in osmotic pressure from saltwater to freshwater will cause ectoparasites to lyse (i.e., swell and burst) or drop off their host after 7-10 minutes, and they will be left behind in the dipping water. Protozoan parasites are microscopic and won’t be visible to the naked eye, but some of the other ectoparasites can be clearly seen. For example, monogenetic trematodes will appear as opaque sesame seeds drifting in the water (Giwojna, Aug. 2003) and nematodes may be visible as tiny hairlike worms 1/16-3/16 of an inch long. Other parasites may appear as tiny dots in the water. Freshwater dips can thus often provide affected seahorses with some immediate relief by ridding them of these irritating pests and can also aid their breathing by flushing out gill parasites.

If you suspect a problem with parasites, the dip should be extended for the full 8-10 minutes if possible for best results. But if you think it’s rarely a problem with dust or sediment that has settled on the seahorse, then there’s no need to prolong the bath beyond a few minutes.

In short, fishfinder, it’s quite possible that the medication you were using had a negative impact on the biological filtration in your aquarium, which resulted in the spike in the ammonia and/or nitrite levels. The combined effects of the ammonia spike and the formalin suppressing the dissolved oxygen levels in the aquarium may essentially have suffocated your seahorses, particularly if they had blanched or were experiencing signs of severe respiratory distress when you lost them…

If you ever have occasion to treat seahorses for marine ick (Cryptocaryon irritans), hyposalinity will eradicate the parasites without the need to resort to chemotherapeutics.

Thank you very much for taking the time to report this incident and to warn other seahorse keepers about the potentially harmful effects of using Ick Attack in a seahorse tank, fishfinder — you may have saved other hobbyists a great deal of grief by doing so! I very much appreciate your posting about this problem and the warning you have provided for all of us fellow seahorse fanatics.

Pete Giwojna

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