I’m very sorry to hear about the problem you’re having with your seahorse, but it’s very difficult to say what may be causing the trouble with so little to go on.
Seahorses will sometimes increase their protective slime coat and form excess mucus to protect themselves from external parasites, and many of these protozoan parasites attack the gills as well as the skin of the fish, so that could possibly have something to do with why your seahorse is sloughing excess slime from her head. A heavy infestation of these parasites will impair the breathing ability of the seahorse.
However, excess slime production and breathing difficulties can also occur if the pH in a marine aquarium is out of whack, and a spike in the ammonia or nitrite levels in your aquarium can also result in lethargy, generalized weakness, and respiratory distress.
And accidental poisoning can also cause the sort of lethargy, respiratory problems, and symptoms you have reported.
In other words, duckabut, we need to know more about the conditions in your seahorse tank and the aquarium itself in order to be of much help. How big is your seahorse tank? What sort of filtration system and equipment do you have on the aquarium? How long has it been up and running? Have you added any new specimens to the aquarium recently or made any other changes (added a new decoration, used any water additives or supplements, etc.)? What kind of seahorses do you have?
Please list all of the current aquarium inhabitants and tell me the current aquarium readings for the following water quality parameters:
Ammonia (NH3/NH4+) =
Nitrite (N02) =
Nitrate (N03) =
specific gravity or salinity =
water temperature =
Without any further information to guide us, the only thing I can recommend at this time would be to perform a major water change or a series of partial water changes in your seahorse tank, and then to treat the female seahorse with methylene blue to ease her breathing, as discussed below:
Commonly known as "meth blue" or simply "blue," this is a wonderful medication for reversing the toxic effects of ammonia and nitrite poisoning (commonly known as "new tank syndrome"). Since hospital tanks are usually without biological filtration, and ammonia and nitrite can thus build up rapidly (especially if you are not doing water changes during the treatment period), it’s a good idea to add methylene blue to your hospital ward when treating sick fish.
Methylene blue also transports oxygen and aids breathing. It facilitates oxygen transport, helping fish breathe more easily by converting methemoglobin to hemoglobin — the normal oxygen carrying component of fish blood, thus allowing more oxygen to be carried through the bloodstream. This makes it very useful for treating gill infections, low oxygen levels, or anytime your seahorses are breathing rapidly and experiencing respiratory distress. It is the drug of choice for treating hypoxic emergencies of any kind with your fish.
In addition, methylene blue treats fungus and some bacteria and protozoans. Methylene blue is effective in preventing fungal infections, and it has antiprotozoal and antibacterial properties as well, by virtue of its ability to bind with cytoplasmic structures within the cell and interfere with oxidation-reduction processes. A "must" for your fish-room medicine cabinet. However, be aware that it is not safe to combine methylene blue with some antibiotics, so check your medication labels closely for any possible problems before doing so.
If you can obtain the Kordon brand of Methylene Blue (available at most well-stocked local fish stores), the instructions for administering it as a very brief, concentrated dip are as follows:
For use as a dip for treatment of fungus or external parasitic protozoans and cyanide poisoning:
(a) Prepare a nonmetallic container of sufficient size to contain the fish to be treated by adding water similar to the original aquarium.
(b) Add 5 teaspoons (24.65 ml) per 3 gallons of water. This produces a concentration of 50 ppm. It is not recommended that the concentration be increased beyond 50 ppm.
(c) Place fishes to be treated in this solution for no longer than 10 seconds.
(d) Return fish to original aquarium.
When you administer such a dip, hold the seahorse in your hand throughout the procedure and time it closely so that the dip does not exceed 10 seconds.
And here are Kordon’s instructions for administering the methylene blue in a hospital tank if longer-term treatment seems appropriate to reverse more severe cases of nitrite poisoning and ammonia toxicity or exposure to high-level of nitrates:
As an aid in reversal of nitrite (NO2-) or cyanide (CN-) poisoning of marine and freshwater aquarium fishes:
(a) Remove carbon filter and continue to operate with mechanical filter media throughout the treatment period.
(b) Add 1 teaspoon of 2.303% Methylene Blue per 10 gallons of water. This produces a concentration of 3 ppm. Continue the treatment for 3 to 5 days.
(c) Make a water change as noted and replace the filter carbon at the conclusion of the treatment.
See the following link for more information on treating with Kordon’s Methylene Blue:
Click here: KPD-28 Methylene Blue
If you obtained a brand of methylene blue other than Kordon, just follow the instructions the medication comes with. Remember that methylene blue will have an adverse impact on the beneficial bacteria that carry out the nitrogen cycle, so don’t use it in your main tank — rather, use the methylene blue as a quick dip or for treating the seahorses for a prolonged period in your hospital tank.
So treat the ailing seahorse with methylene blue as soon as possible, and concentrate on improving the water quality in your seahorse tank through a series of water changes. If possible, transfer the seahorse to a hospital tank and administer a long-term regimen of the methylene blue.
Please get back to me with the additional information I requested as soon as possible, duckabut.