Betta (Siamese fighting fish)

Clinical context for betta dosing

Fish are usually dosed through the water or through medicated feed rather than by injection, so a dose is often a concentration in the system — milligrams per litre for a set immersion time — and depends on the volume being treated, the temperature, and water chemistry as much as on the weight of the fish. Check the unit before anything else: an immersion concentration used as a per-kilogram dose is a serious overdose, and the reverse is a treatment failure. Uptake for immersion agents is largely across the gill, so respiratory rate and oxygenation drive both effect and risk. For any fish that may be eaten, withdrawal periods apply.