STEP 1: EQUIPMENT

First lay out all the equipment required:

• Protective clothing - apron and gloves.
• Curved scissors or clippers.
• Antiseptic solution such as Hibiscrub or Pevidine.
• Cotton wool or swabs.
• Industrial methylated spirit.
• Blood tubes (see Key Notes: Blood Tube Colour Codes).
• Syringe and needle (size chosen according to the size of the patient). NB A vacutainer may be used rather than separate blood tubes, syringe and needle
• Assistant to restrain the patient.

STEP 2: PROCEDURE

1. Collect together the equipment as specified in Step 1.
2. Don protective clothing and ask the assistant to restrain the animal.
3. Select a suitable vein: frequently used are:
   Jugular (neck)
   Cephalic (forelimb)
   Saphenous (hindlimb)
   Femoral (hindlimb)
4. Position the animal.
5. Clip the site for venipuncture with curved scissors or clippers, ensure that the area is neat.
6. Clean the site for venipuncture with an antiseptic scrub solution such as Hibiscrub or Pevidine, working from the middle to the outsides discarding the dirty swabs as you go (continue until no further dirt is visible on the swabs).
7. Apply spirit to ensure that no water remains on the site; water may cause osmotic changes leading to haemolysis of the sample.
8. Use digital pressure to occlude the vein and locate its position.
9. NEEDLE & SYRINGE METHOD
   A suitable needle (usually 23-21g x 5/8) is attached to a 2ml, 5ml or 10ml syringe depending on the quantity of blood required. The needle is carefully introduced into the vein, and the plunger slowly and steadily pulled back in order to draw blood into the syringe. Once the desired amount of blood is collected, remove the needle from the vein, cease digital pressure and apply a swab to the venipuncture site to stem further bleeding. Remove the needle from the syringe and gently expel the blood into the collection tubes filling to the level marked upon the side. Replace the lids and roll or invert to mix the anticoagulant with the blood (never shake as this may cause haemolysis).
   
   VACUTAINER METHOD
   Take a double ended needle and the appropriate vacutainer. Push one end of the needle into the rubber bung, taking care not to much it all the way through or you will lose the vacuum. Insert the other end of the needle into the vein, then push the vacutainer further onto the needle. The vacuum will then draw blood into the tube. This method is advantageous in that it offers more sterility than the needle and syringe technique. The main disadvantage is that excessive pressure may cause the vein to collapse. Invert or roll the tube to mix the sample with the anticoagulant.
10. Label the sample with the date, owner's surname, animal's name or identification and the name of the veterinary surgeon in charge of the case.
11. If the sample is to be sent to an external laboratory, complete a submission form and package the sample as per Module 3 - The Dispatch of Samples To External Laboratories.
12. Ensure that the sample is correctly stored in the refrigerator or freezer if necessary.
    
    NB Serum collection requires a plain tube; wait for 1-2 hours for the blood to clot and then pipette the serum off. Plasma collection is collected in a tube containing anticoagulant; the sample is centrifuged and then the plasma may be drawn off with a pipette.