Fast animals for 12-24 hours prior to anesthesia to decrease incidence of regurgitation since MS222 can cause GI response. The action of MS222 as an anesthetic varies widely between species and is affected by water temperature, hardness, and size of the individual animal. Preliminary tests are recommended to determine concentration and exposure time for each application to assure sufficient anesthetic depth and safe recovery. Allow animal to reach appropriate level of anesthesia for planned procedure. There are narrower margin of safety in young fish, and soft, warm water. Maintain adequate oxygenation of the animal throughout induction, anesthesia and recovery. Oxygenation of the water can be accomplished by supplying pure oxygen via diffusers or similar devices. Aeration can be accomplished when biomass in the anesthesia container is low by supplying clean air via an air pump and air stone, or similar devices. In amphibians, anesthesia induction can be in a water bath. When inducing a terrestrial amphibian in an immersion anesthetic bath, keep the animal’s head and nares above the water line to prevent accidental drowning. In some cases, anesthesia with MS222 can be maintained by dripping a dilute solution of this drug over the skin or by covering animals with a paper towel moistened with the anesthetic. Higher concentrations of MS222 result in rapid anesthesia with shorter maximum tolerated exposure times, which are recommended for induction. Lower concentrations of MS222 result in longer induction times and longer maximum tolerated exposure times, which are recommended for maintenance of anesthesia. After procedures are completed place animals in well oxygenated/aerated, water or in a container lined with wet towels (terrestrial amphibians). Closely monitor fish/amphibians recovering from anesthesia until they are swimming/moving normally and completely regained their righting response. Recommended Dosages for Anesthesia Taxonomic Rank Dosage Comments Fish 15-50 mg/L Sedation 50-200 mg/L Induction 50-100 mg/L Maintenance 1 g/L Spray – large fish on gills directly Amphibians 50-200 mg/kg Most species – intracoelomic injection Frogs/Salamander 0.5-2 g/L Bath to effect/induction in 15-30 min Leopard Frogs 100-200 mg/L Intracoelomic injection Bullfrogs 100-400 mg/L Intracoelomic injection
Fast animals for 12-24 hours prior to anesthesia to decrease incidence of regurgitation since MS222 can cause GI response. The action of MS222 as an anesthetic varies widely between species and is affected by water temperature, hardness, and size of the individual animal. Preliminary tests are recommended to determine concentration and exposure time for each application to assure sufficient anesthetic depth and safe recovery. Allow animal to reach appropriate level of anesthesia for planned procedure. There are narrower margin of safety in young fish, and soft, warm water. Maintain adequate oxygenation of the animal throughout induction, anesthesia and recovery. Oxygenation of the water can be accomplished by supplying pure oxygen via diffusers or similar devices. Aeration can be accomplished when biomass in the anesthesia container is low by supplying clean air via an air pump and air stone, or similar devices. In amphibians, anesthesia induction can be in a water bath. When inducing a terrestrial amphibian in an immersion anesthetic bath, keep the animal’s head and nares above the water line to prevent accidental drowning. In some cases, anesthesia with MS222 can be maintained by dripping a dilute solution of this drug over the skin or by covering animals with a paper towel moistened with the anesthetic. Higher concentrations of MS222 result in rapid anesthesia with shorter maximum tolerated exposure times, which are recommended for induction. Lower concentrations of MS222 result in longer induction times and longer maximum tolerated exposure times, which are recommended for maintenance of anesthesia. After procedures are completed place animals in well oxygenated/aerated, water or in a container lined with wet towels (terrestrial amphibians). Closely monitor fish/amphibians recovering from anesthesia until they are swimming/moving normally and completely regained their righting response. Recommended Dosages for Anesthesia Taxonomic Rank Dosage Comments Fish 15-50 mg/L Sedation 50-200 mg/L Induction 50-100 mg/L Maintenance 1 g/L Spray – large fish on gills directly Amphibians 50-200 mg/kg Most species – intracoelomic injection Frogs/Salamander 0.5-2 g/L Bath to effect/induction in 15-30 min Leopard Frogs 100-200 mg/L Intracoelomic injection Bullfrogs 100-400 mg/L Intracoelomic injection
Guidelines_for_the_Preparation_and_Use_of_MS222_Feb14_Final.docx