I understand that this is pretty dangerous stuff.
This is a product which has, until recently, been widely available. It was used for the treatment of the more stubborn parasites such as fish lice, anchor worm, leeches etc. It was used at a dose
rate of 1 gm to 660 gallons of water at 55 F, up to a dose of 1 gm to 87 gallons of water at higher temperatures. It is however illegal and has been withdrawn from sale in the U.K. which has
led to hobbyists using similar remedies which are NOT SUITABLE FOR THE TREATMENT OF FISH. These are: Dipterex, Naled etc. Masoten is not suitable for short term baths or dips.
Beware of residual toxicity
Beware of overdosing
Do not store when mixed"
Koi parasite Skin fluke
Gyrodactylus - The Skin Fluke. (left)
Koi suffering from infestations of gill flukes may suffer respiratory problems as the flukes begin to damage the delicate gill tissues. Secondary bacterial infection often occurs in koi left suffering from these parasites, due to the physical damage caused by the anchors.
Chemical control of both types of fluke can be achieved with Chloramine T, Malachite Green and Formalin , Potassium Permanganate or Supaverm. In order to kill all generations, repeat treatments may be necessary, the frequency being dependent on temperature and chemical used.
In our experience, Potassium Permanganate is the best 'legal' treatment for flukes, but one dose of Supaverm will eradicate flukes very effectively. Masoten can also be added to Malachite and Formalin to make this a more effective Fluke treatment.
If the life cycle of Gyrodactylus and Dactylogyrus is full understood treatment becomes much or effective and predictable, it must therefore be understood that save one treatment a single treatment alone will not eradicate gill fluke, so we must employ multiple sequenced treatments the time span of which will be determined by the water temperature, since we are aiming to catch the emerging hatchling fluke as well as the parent,
The parent is easily dealt with by many treatments, potassium permanganate, formalin, chloramines T or Masoten, The latter of which is restricted in its use being an organophosphate, but ultimately has been over used by the Japanese breeders in their endeavour to over come fluke infestations and as such we have seen a mutation of fluke that can survive Masoten exposure
Formalin whilst being effective treatment in many ways is a very efficient consumer of valuable pond water oxygen, and therefore as the koi may have compromised gill function would not be a first line choice of treatment.
(Antibiotics do not eliminate flukes or any other parasites) just I case you were wondering, they only work against bacteria.
Gill and skin flukes are common external parasites of koi presented to the Fish Health Service at the University of California, Davis. Therapeutic compounds commonly employed by koi hobbyists in attempt to treat external fluke infestations include salt, potassium permanganate, formalin (alone or in combination with malachite green), Fluke Tabs®, organophosphates (such as malathion, trichlorfon or Masoten®, Dylox®) and praziquantel (Droncit®). There are various difficulties encountered with these agents.
- presence of gill flukes on the gills and body
- labored breathing
- swimming in jerky motions
- gill hyperplasia and increased mucus
- long periods of rest at the bottom of the pond with clamped fins
- reddening of some focal areas
- can create entry points for secondary bacterial infections, which in turn can lead to gill diseases and ulcers
- gill flukes are more difficult to treat than skin flukes
- regular salt baths, as well as special treatments with malachite green and formalin may produce results; masoten may be required for severe cases
Gill and skin flukes are common external parasites of koi. Therapeutic compounds commonly employed by koi hobbyists in attempt to treat external fluke infestations include salt, potassium permanganate, formalin (alone or in combination with malachite green), Fluke Tabs®, organophosphates (such as malathion, trichlorfon or Masoten®, Dylox®) and praziquantel (Droncit®). There are various difficulties encountered with these agents.
Problems with commonly used treatments center around efficacy (i.e., a compound may not work effectively) and potential toxicity (to either the fish, the person applying the treatment, or the aquatic environment downstream). As examples of the former, we have increasingly observed salt and formalin to be ineffective for fluke eradication. This is presumably due to increasing resistance amongst strains of flukes that have been chronically exposed to these treatments. Potassium permanganate regimens, while usually effective, are sometimes complex for individual hobbyists to implement, and carry a fair degree of risk if excessive doses are delivered accidentally. Praziquantel is effective but expensive, and therefore is not usually a practical treatment for fluke infestations in the pond setting. Organophosphates, either used alone or in combination with a carbamate (as in the Fluke-Tab® product), have the multiple problems of developing resistance in the flukes (decreasing efficacy), potential toxicity to the fish if over-dosed, and environmental concerns (as well as safety concerns for the person applying the treatment).