Blood vessel cannulation

Please read the general principles of blood sampling and catheterisation pages before attempting any cannulation procedure.


Cannulation should be considered when repeated samples are required as it avoids multiple needle entries at any one site and can therefore minimise distress in potentially aggressive animals such as ferrets. It is suitable for use in all strains of ferret and can be used to take blood from the carotid artery and femoral vein. Surgery is required and appropriate anaesthesia, analgesia and aseptic technique should be used to minimise pain. Ferrets should be allowed to regain their pre-operative body weight before blood samples are taken.

For recovery work the cannula is exteriorised at the nape of the neck and secured by a crepe bandage. The use of a subcutaneous access port or button should be explored since these can eliminate the need for the bandage. For terminal work, the cannula is not exteriorised.

Cannulated ferrets are usually housed singly. The caging, bedding and environmental enrichment needs to be appropriate to prevent the bandage becoming entangled and the wound contaminated.

Small cannulas will increase the risk of blood clotting (large cannulae can abrade the blood vessel wall). To prevent this, the cannula requires regular maintenance (e.g. regular flushing with an appropriate lock solution. See our preventing thrombosis page for more information).

Blood should be collected aseptically. Usually, 0.1 - 0.5 ml can be taken per sample. Depending on the sample volume and scientific purpose, up to six samples over a two hour period or up to 20 samples over a 24-hour period may be taken. Sterile saline with anticoagulant should be flushed into the cannula after blood sampling to prevent the blood from clotting. A pin is then inserted into the exteriorised end of the cannula, which stops the blood from flowing. A sterile locking solution can be used to lock the cannula after a series of samples have been taken, allowing flushing to be avoided for a number of days.

The following should be checked daily

  • The bandage should be checked for tightness.
  • If a jacket is used, this should be checked for tightness and the skin in contact with the jacket checked for abrasion.
  • Wound sites should be checked for infection/bruising/swelling/haemorrhage.
  • The cannula should be checked for patency (without blockage).
  • The weight of the ferret should also be monitored.

Changes in any of the above may require veterinary advice or treatment, or may indicate that a humane endpoint has been reached and appropriate action should be taken.


Number of samples Up to 20 samples may be taken in a 24-hour period, depending on the sample volume.
Sample volume 0.5 ml
Equipment 19G cannula
Staff resource Two people are required: one to take the blood sample and another to restrain the ferret.
Adverse effects
  • Infection 1-5%
  • Haemorrhage 1-5%
  • Blocked cannula 1-5%
Other Ferrets should be at their pre-operative weight before blood sampling starts.

Resources and references

Blood vessel cannulation technique in other animals

Click here for information on blood vessel cannulation in the mouseClick here for information on blood vessel cannulation in the ratClick here for information on blood vessel cannulation in the guinea pig 

All blood sampling techniques in the ferret

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