Dorsal coccygeal vein
Easier in males than in females, as males have longer and thicker tails. The tail
is extended and the needle is inserted with a 45-90° angle in the dorsal midline,
aiming to the coccygeal vertebrae. Once a vertebra is touched, start making
negative pressure with the syringe while the needle is slowly pulled back until
the vein is reached.
Subcarapacial vein or sinus
Easy to find in many individuals, particularly those which retract the head
inside the carapace. The needle is inserted in the midline area of the skin, dorsal
to the neck and very close to the junction of the skin with the carapace, and
directed dorsally, towards the junction between the cervical vertebrae and the
interior aspect of the carapace.
Jugular vein
Difficult to find in some species, particularly freshwater turtles. More appropriate in tortoises, although the vein is still difficult to notice or palpate.
In some species there are dorsal and ventral jugular veins. The head is extended and the needle is inserted with a very low angle in the neck, at the level of a parallel line that includes the dorsal edge of the tympanic membrane (dorsal jugular vein) or the ventral edge of the tympanic membrane (ventral jugular vein). The carotid artery is associated with the jugular vein and when sampled(incidentally or purposely) the syringe fills quickly with bright red blood.