Jugular vein

Technique

Sampling from the jugular vein can be used with all strains but requires a high degree of competence to avoid moderate or significant harm to the rat. Its use should be limited, for instance, to studies where blood collection is required immediately after dosing (e.g. inhalation and infusion studies) or where a sampling site distal to the dosing site is required (e.g. intravenous studies). Warming of the rat is not required.

One person is required to take the blood sample and another to restrain and monitor the rat. The rat's forepaws are tied to a sloped restraint board with cotton cord tethers and the rat held in dorsal recumbancy with one person holding the abdomen and legs. Care needs to be taken in applying the restraint to prevent damage to the fore limbs. The person taking the blood sample controls the head by the use of a head cap. Blood is taken from a small triangle just under the scapula. The head is tilted at an angle in the head cap, which makes the site of sampling prominent.

The rat is restrained in an unnatural position, which can cause stress. The ties used to hold the forepaws can cause to damage to the limbs and nerves in this area, causing lameness. Tilting the head of the rats in the head cap can cause haemorrhage to the ears. The rat can also lose consciousness. The duration of restraint should be kept to a minimum. The rat's respiration should be observed continuously by the person restraining the animal and the ties used to restrain the forepaws should be tightened carefully. Care should be taken when tilting the head in the head cap.

Sampling should be carried out aseptically. 0.1 - 2 ml (normally 0.1 - 0.3 ml) of blood can be collected per sample and, depending on the sample volume and scientific justification, up to eight samples in a 24-hour period. The number of needle sticks at each attempt should be a limited to three. If more samples are needed, then surgical cannulation or temporary cannulation of a different blood vessel should be considered. Use of local anaestheic cream (e.g. EMLA cream) applied to the site 30 minutes prior to sampling can help relieve any pain.

Blood flow should be stopped before the rat is returned to its cage by releasing the cords tied to the fore limbs, turning the animal over and applying gentle pressure to the blood sampling site for ten seconds.

Summary

Number of samples No more than eight blood samples should be taken in a 24-hour period.
Sample volume 0.1 - 2 ml (normally 0.1 - 0.3 ml)
Equipment 23G (preferably 1" long) needle
Staff resource Two people: one to take the blood sample and another to restrain and monitor the rat.
Adverse effects
  • Bruising
  • Infection <1%
  • Haemorrhage <1%
Other Rats are restrained in an unnatural position, which can cause stress. A high degree of competence is required to perform this technique.

Resources and references

Jugular vein sampling in other animals

Click here for information on jugular vein blood sampling in the dog

All blood sampling techniques in the rat

Click here for information on blood vessel cannulation in the ratClick here for information on tail vein blood sampling in the ratClick here for information on saphenous vein blood sampling in the ratClick here for information on retro-orbital blood sampling techniques in the ratClick here for information on using a temporary cannula for blood sampling in the ratClick here for information on abdominal/thoracic blood vessel blood sampling in the ratClick here for information on cardiac puncture blood sampling in the ratClick here for information on schedule 1 stunning followed by decapitation for blood sampling in the ratClick here for information on decapitation blood sampling techniques in the rat