It used to be that you should only inject some medications into the front legs, because otherwise they would be either a) filtered out by the kidnesy or b) could be toxic to the kidneys. This is not true anymore. The notion that forelimb and hind limb injections are equivocal is gaining acceptance. If you need to give injections over a longer period of time, discuss with your veterinarian where to give them so that you can vary the injection sites. (It's also usually easier to inject in the rear legs.) Make sure you distinguish between subcutaneous (under the skin), intramuscular (into the muscle), and intravenous (into the blood stream) injections. In any case; if you are going to inject your turtle, discuss it with your veterinarian and make sure s/he shows you exactly what and how to do it. Here are some references: Holz P, Barker IK, Burger JP, Crawshaw GJ, Conlon PD: The effect of the renal portal system on pharmacokinetic parameters inthe red-fared slider (Trachemys scripta elegans). J.Zoo.Wildlife.Med. 1997;V28:386-393. Holz P, Barker IK, Crawshaw GJ, Dobson H: The anatomy and perfusion of the renal portal system in the red-eared slider (Trachemys scripta elegans). J.Zoo.Wildlife.Med. 1997;V28:378-385. Holz P, The reptilian Renal portal system and its effect on drug kinetics. D.V.Sc. dissertation, Univ. of Guelph, 1994 Holtz P, Chapter 32: Reptilian Renal Portal System: Influence on Therapy. In: Fowler, ME and Miller, RE (eds) Zoo and Wild Animal Medicine: Current Therapy 4, W.B. Saunders 1999 Beck K, Loomis M, Lewbart G, Spelman L, Papich M: Preliminary comparison of plasma concentrations of gentamicin injected into the cranial and caudal limb musculature of the eastern box turtle (Terrapene carolina carolina). J.Zoo.Wildlife.Med. 1995;V26:265-268. Benson KG, Forrest LJ: Characterization Of The Renal Portal System Of The Common Green Iguana (Iguana Iguana) With Digital Subtraction Imaging. J.Zoo.Wildlife.Med. In Press