Injection
Manual Injection A prerequisite for injection is that the fish should be anaesthetized; without this precaution injury is likely to be caused to the fish and possibly also to the operator. Intramuscular injection Intramuscular injections are given into the epaxial musculature, normally approximately mid-way between the mid-dorsal line and the lateral line. Intraperitoneal injection Intraperitoneal injections are made into the mid-ventral line just cranial to the vent. This is a widely used route of injection but it can sometimes cause peritoneal adhesions. In consequence intraperitoneal injection should be avoided; the dose is likely to be made into a viscus or the lumen of the gut. Injection into the dorso-median sinus A route of administration which is being recommended for salmonids is into the dorso-median sinus (DMS). The point of insertion of the needle is in the mid dorsal line in the angle at the caudal margin of the cranial dorsal fin. This route is unsuitable for most fish other than salmonids because of their different anatomy. Automatic Injectors Multiple dose syringes are available for injecting drugs into mammals rarely deliver accurate doses of drug volumes to fish. However automatic injectors used for vaccinating poultry are suitable for vaccinating fish. Machine injection Machines are available for the rapid injection of large numbers of fish. In practice this means vaccination by the intraperitoneal route. Anaesthesia is not needed with the machine, but even so use of the machine is safer for the operator than manual procedures with anaesthesia. |