Blood vessel cannulation

Technique

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 and analgesia 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 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.

The ferret is held for restraint and the bandage may be used to restrict movement. 0.5 ml of blood can be taken, and depending on the sample volume and scientific justification, up to 20 samples can be taken in a 24-hour period. An aseptic technique should be used. 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 to stop the blood from flowing. The wound site and cannula should be checked, and the ferret weighed, daily.

The cannula is small which can promote blood clotting. To prevent this, the cannula requires regular maintenance, (e.g. daily or twice daily flushing). Ferrets can show signs of dullness and ataxia after flushing, possibly as a result of alcohol in the anti-coagulant solution, and to minimise this, flushing should be carried out slowly. Use of heparin-bonded cannulae can help reduce the incidence of cannula blockage.

Summary

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