Marginal ear vein/artery

Please read the general principles of blood sampling page before attempting any blood sampling procedure.

Technique

Removal of blood from the marginal ear vein or artery is one of the most common and least invasive methods of talking blood from a rabbit. This technique can be used with all strains and for single and repeat samples. Use of the artery is normally used for larger volume samples or for arterial blood, but carries a greater risk of haematoma and bruising.

Slides and video for sampling from the central ear artery are available on the website of the Norwegian Reference Centre for Laboratory Animal Science and Alternatives.

The rabbit should be restrained and it can be helpful to wrap the animal in a large cloth to avoid inadvertent movement. Restraint can cause stress, therefore the duration of restraint should be minimised. Blood is taken from the tip of the ear, away from the base of the ear. Serial blood samples can be taken by moving towards the base of the ear on the same vein and by alternating ears. The ear should be warmed in order to dilate the vessel. This can be done by gently stroking; it should not be necessary to use a heat lamp. The dorsal surface of the ear should be clipped.Please note that hair removal by shaving with a scalpel blade is no longer recommended as it removes the epidermal layers of the skin. An aseptic technique should be used. Anaesthesia is not necessary but may be used on welfare grounds for animals that are difficult to hold.  The vein is normally occluded distally (away from the animal) before the needle is inserted.

Depending on the size of the rabbit and the frequency of sampling, 0.5 - 10 ml of blood can be collected. Up to eight samples can be collected in any 24-hour period, depending on sample volume and scientific justification. In order to minimise damage to the ear the number of attempts to take a blood sample should be minimised (no more than three needle sticks in any one attempt).

Blood flow should be stopped before the animal is returned to its cage or pen by applying finger pressure on the soft tissue placed at the blood sampling site for approximately two minutes.

Summary

Number of samples Up to eight samples may be taken in any 24-hour period, depending on sample volume.
Sample volume Up to 0.5 - 10 ml, depending on the size and strain of the rabbit.
Equipment 19G - 23G butterfly needle, depending on the strain and size of the rabbit.
Staff resource Two people: one to restrain the rabbit and the other to take the blood sample.
Adverse effects
  • Bruising/haemorrhage <1%
  • Infection <1%

Resources and references

Marginal ear vein/artery sampling in other animals

This technique is only appropriate for use in the rabbit

All blood sampling techniques in the rabbit

Click here for information on cardiac puncture blood sampling in the rabbit