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 25-28 September, 2018 | Singapore
5. Use lithium heparin tubes (green top) for bio- chemistry and Na EDTA tubes (purple top) for haematology, unless your lab makes a different recommendation.
6. Ensure the blood and anti-coagulant are mixed immediately by rolling the tube along the palm of your hand or gently inverting the tube 10 times. Do not shake the sample, as this may result in haemolysis.
7. If sample processing is likely to be delayed more than a few hours, centrifuge the lithium sample and separate the plasma from the red cells. Decant the plasma and place in another lithium heparin bottle. This prevents artefacts associated by prolonged contact time with the erythrocytes.
8. Avoid over-interpretation of results. Look for significant elevations or decreases, not changes that could be within the range of error or normal variations for the machine or patient. Be aware of artefactual changes affecting some parame- ters e.g. hyperkalaemia due to haemolysis.
9. Always treat your patient, not your test results!
Blood collection and handling
Birds: Blood can be collected from the right jugular vein (the left jugular vein is accessible, but is much smaller), the basilic vein (on the medial aspect of the elbow)
or the medial tibiotarsal vein (in large birds). The right jugular vein is usually preferred in companion birds because of the relatively easy access; it lies under an apteryla and, with practice, a sole operator can both restrain the bird and perform the venepuncture. It must be remembered that avian veins have thin walls and tear easily. Coagulation in birds usually relies on extrinsic clotting pathways requiring tissue thromboplastin, rather than the intrinsic clotting pathways utilized by mammals. Care must therefore be taken to prevent accidentally tearing the vein wall, which can lead to a rapidly fatal haemorrhage. It is advisable to apply digital pressure to the venepuncture site for 30–60 seconds to minimize haematoma formation. Using a 25–29-gauge needle minimizes the iatrogenic trauma to the vein, but the smaller the needle bore the more likely haemolysis
is to occur during collection. Once the needle has entered the vein, avoid using excessive pressure to draw back; this will prevent both collapsing the vein and haemolysing the sample. It is sometimes advantageous to use a heparinised syringe for blood collection.
Reptiles: Blood can be collected from most reptiles with varying degrees of difficulty.
1. Snakes – collect from the ventral tail vein or, if unsuc- cessful, from the heart
2. Lizards – collect from the ventral tail vein. Be careful of autonomy in skinks and geckos
3. Turtles – collect from the jugular vein or the dorsal sub-carapacial venous sinus
Small mammals: There are a number of venepuncture sites that can be used in small mammals
The reasons why blood results may vary from reference intervals
Haematologic or biochemical parameters in the blood can be influenced by either physiological or pathological processes. Physiological variations can be due to
age, sex, body fat to muscle ratio, nutritional status, reproductive status and species. However, pathological processes, including cellular damage or abnormal function of an organ system (or systems), often produce significant changes in parameters.
There are three major causes of abnormal laboratory results:
· Normal variation between species and individuals · Artefacts
· Pathology
Normal variation between species and individuals
We are dealing with three classes of exotic pets, with hundreds of species presented for veterinary care. There are major differences in anatomy, physiology, form and function. Some are carnivorous, some are herbivorous, and some are omnivorous. It is unrealistic to expect that they would all conform to a relatively narrow range of haematologic and biochemical values.
Other variations arise between individuals of the same species. These variations occur because of differences in age, sex, diet, husbandry, etc. For this reason some clinicians recommend establishing a set of normal values for individual animals during annual health examinations, and then using these values as a comparison should the animal become ill.
  Guinea Pig
   Rat and mouse
   Marginal ear vein
   Anterior vena cava
   Lateral saphenous
   Lateral tail
     Orbital venous sinus

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