Wm. Kirk Suedmeyer, DVM
Manual and chemical restraint of ratites, including emus (Dromaius novaehollandiae) is universally employed to obtain blood specimens for analysis.1-5 Restraint often alters the results of the complete blood count (CBC), creatinine phosphokinase (CPK), and aspartate aminotransferase (AST) in emus and other avian species.1-5 In addition, safety concerns arise for the handler and the bird when restraint is employed.1
We devised a method for obtaining blood samples from emus without restraint. Blood specimens obtained in this manner may accurately reflect true blood values rather than those influenced by restraint. In our case, we obtained blood from the right jugular vein in three clinically healthy, manually restrained emus, and in the same three emus more than 6 months later with this new technique. In each case, values for CPK, AST, and CBC were significantly different from those values obtained without restraint.
With restraint, blood is obtained from the right jugular vein or medial metatarsal vein.1-5 The basilic vein in emus is difficult to access due to the size of the vestigial wing.3,4
We utilized a standard 19 or 23 ga vacutainer system (Becton Dickinson Vacutainer Systems, Franklin Lakes, NJ, USA) for obtaining blood samples. A lithium heparin tube or an EDTA tube is taped in an upright position on the medial aspect of the tarso-metatarsus along with the butterfly catheter. Lithium heparin is the preferred collection tube for plasma chemistries, and EDTA is preferred for hematology, as lithium heparin may interfere with leukocyte counts, and EDTA can interfere with calcium levels.2 Some laboratories have better success analyzing ratite samples stored in citrated tubes.3
The medial metatarsal vein is visualized, cleansed, and accessed with the butterfly needle. After a step or two by the emu, the opposite end of the extension set is inserted in the vacutainer and blood freely flows into the tube. An added benefit is that the emu usually walks away, thereby mixing the blood adequately. After filling, the tube is removed, and the sample processed routinely.
We have found that values in unrestrained emus are statistically different from manually restrained emus, and may reflect more accurate baseline values in emus. We believe this method can also be employed in ostrich (Struthio camelus).
Advantages of this technique are generally increased safety, less manpower, and a more accurate reflection of blood values. Disadvantages include uncooperative patients and some risk for being kicked by the emu. Fractious birds should only be handled by experienced handlers or sedated for blood sampling.1
1. Blue-McLendon A. Basic techniques of ratite restraint and handling. In: Proceedings of the Association of Avian Veterinarians. 1994:309–310.
2. Campbell TW. Hematology. In: Ritchie BW, Harrison GJ, Harrison LR, eds. Avian Medicine: Principles and Application. Lake Worth, FL: Wingers Publishing; 1994:176–198.
3. Fudge AM. Clinical hematology and chemistry in ratites. In: Tully TN, Shane SM, eds. Ratite Management, Medicine, and Surgery. Malabar, FL: Kreiger Publishing Co.; 1996:105–106,111.
4. Fudge AM. Avian clinical pathology-hematology and chemistry. In: Altman RB, Clubb SL, Dorrestein GM, Quesenberry K, eds. Avian Medicine and Surgery. Philadelphia, PA: W.B. Saunders; 1997:143–150.
5. Fudge AM. Blood testing artifacts: interpretation and prevention. Sem Avian Exotic Pet Med. 1995;3:2–4.