What are the correct medication methods for fish?

Administration of drugs

The drugs used to prevent and treat fish diseases mainly include halogens (bleaching powder, sodium chloride, iodine, etc.), heavy metal salts (copper sulfate and ferrous sulfate, copper chloride, potassium dichromate, etc.), sulfonamides (sulfadiazine, sulfathiazole, sulfaguanidine, etc.), furans (nitrofurazone, furazolidone, etc.), organophosphate insecticides (trichlorfon, etc.), antibiotics (penicillin, streptomycin, chloramphenicol, chlortetracycline, oxytetracycline, erythromycin, etc.), Chinese herbal medicines (, , garlic, Euphorbia humifusa, Acalypha australis, etc.), as well as other dyes with bactericidal effects such as malachite green and methylene blue, quicklime, sulfur, borax, potassium permanganate, etc.

There are usually the following 4 methods of drug administration:

① Hanging bag (basket) method.

A bag or basket containing the drug is hung in the water body around the feeding tray or feeding ground of the fish pond, forming a drug action zone. Within the range of drug concentration that the fish can tolerate, the fish automatically enter and leave this zone and are affected by the drug, so as to kill pathogens on the body surface and gills. It is generally used for prevention or early treatment. Copper sulfate and ferrous sulfate are commonly hung in bags to prevent and treat grass carp wheel disease, Chinese anchor worm disease, etc., and bleaching powder is hung in baskets to prevent and treat red skin disease, gill rot disease, etc. of black carp and grass carp.

② Dipping and washing method.

The fish are immersed in a container with a relatively high concentration of the drug, and the drug is forcibly administered for a shorter time, thereby killing pathogens on the fish body surface or gills without harming the fish itself. Common salt at a 2% concentration and nitrofurazone at a 20 ppm concentration are commonly used to prevent and treat myxobacterial white head and white mouth disease, gill rot disease, etc., and potassium permanganate at a 10-20 ppm concentration is used to prevent and treat gyrodactylosis, dactylogyrosis, etc.

③ Broadcast sprinkling method.

It is the most commonly used method. That is, a drug concentration that has a killing effect on a certain pathogen but is safe for the fish itself is sprinkled throughout the fish pond to kill pathogens on the fish body surface, gills and in the water body. When using this method, the volume of pond water and the dosage must be calculated accurately. A mixture of copper sulfate 0.5 ppm and ferrous sulfate 0.2 ppm is commonly used to treat wheel disease, ichthyobodosis, chilodonelliasis, Chinese anchor worm disease, etc.; rhubarb at a 2.5-3.75 ppm concentration is used to treat myxobacterial white head and white mouth disease, gill rot disease, etc.; crystalline trichlorfon at a 0.25-0.5 ppm concentration is used to treat dactylogyrosis, argulosis, etc.

④ Oral administration method.

The drug is mixed into the bait to make palatable pellets and fed to the fish. This is a method of drug prevention and treatment for diseases of internal organs. Raw garlic and salt, or sulfaguanidine, are commonly used to prevent and treat enteritis in black carp and grass carp, and a mixture of sulfathiazole or sulfur powder and iodine tablets is used to prevent and treat coccidiosis in black carp.

⑤ Injection method

For example, vaccines are injected to prevent some viral or bacterial fish diseases, and penicillin or streptomycin is injected to treat printing disease and postpartum injuries in broodstock of grass carp, silver carp, and bighead carp.