The table below lists the maximum acceptable needle size for administration or sampling. Select the smallest gauge possible for injections and sampling, to minimize stress to the animal, and the chance of leaking from puncture site after the needle is withdrawn.
Approximate volumes for fluid replacement therapy by intraperitoneal or subcutaneous administration
Species | Method | Needle Size | Site | Volume |
---|---|---|---|---|
Mouse | SQ | 25 gauge | Scruff of neck | 1-1.5mL at 2-3 sites |
IM | 25 gauge | Quads, post, thigh | 0.03mL | |
IP | 25 gauge | 1-2mL | ||
IV | 25 gauge | Lateral tail vein | 0.2-0.4mL | |
Gavage | 22 gauge, 2-3 cm, feeding needle | 5-10mL/kg (1mL/mouse) | ||
Rat | Sub-Q | 25 gauge | Scruff, back | 5-10mL (2-3 sites) |
IM | 25 gauge | Quads, post, thigh | 0.03mL | |
IP | 25 gauge | 4-5mL | ||
IV | 23 gauge | Lateral tail vein | 0.5mL | |
Arterial | 25 or 27 gauge | Ventral tail | withdraw only | |
Gavage | 18 gauge, 6-8 cm long | 5-10mL/kg(3mL/rat) | ||
Rabbit | Sub-Q | 23 or 22 gauge | Scruff, back | 30-50mL (2sites) |
IM | 23 or 25 gauge | Quads, lumbar muscles | 0.5-1.0mL | |
IV | 23 gauge | Marginal ear vein | 1 - 5ml (slowly) withdrawn only |