Blood collection and intravenous injections in Alpaca
Alpaca veins, especially those of the neck, are difficult to access compared to moat other livestock species. You cannot feel the vein when raised because of a thick muscle layer over the jugular vein that is not present in most other species.
There are two spots on the alpaca neck that one can obtain blood or inject intravenously, the high site and the low site.
High Site:
A line is drawn between the bottom of the jaw and the neck (fig 1C) to determine the point of collection.
The advantage of this site is that the jugular vein and the carotid artery are separated making penetration of the artery less likely. This is important when administering drugs where arterial administration could be fatal. e.g. Anaesthetics, sedatives.
The disadvantages of this site are that the skin is thicker and that small movements of the head make collection more difficult.
Low site:
In the lower neck there are a couple of bony processes that can be felt on most alpacas (fig.1D). These processes are the landmarks for palpating the presence of the jugular vein. A thumb is placed below either process to engorge the vein, and then the needle is inserted slightly towards the middle of the neck.
The advantages of this site are that the skin is thinner and that movement of the head has less of an influence on successful collection.
The disadvantage is that the carotid artery and jugular vein sit on top of each other, meaning that arterial penetration is quite common. This is less significant if blood collection is the aim but a serious problem if certain drugs wish to be administered intravenously.