- Resources and references
- Blood vessel cannulation technique in other animals
- All blood sampling techniques in the guinea pig
Cannulation should be considered when repeated samples are required as it avoids multiple needle entries at any one site. It is suitable for use in all strains of guinea pig and can be used to take blood from the femoral vein, carotid artery and vena cava. Surgery is required and appropriate anaesthesia and analgesia should be used to minimise any pain caused. Guinea pigs should be allowed to regain their pre-operative body weight before blood samples are taken.
The cannula is exteriorised at the nape of the neck (through a jacket and tether system). The jacket can cause swelling and skin abrasion and guinea pigs require regular and detailed observation to identify any problems. The use of a subcutaneous access port may be more appropriate because they eliminate the need for tethering systems during periods when animals are not being sampled from.
The jacket and tether system can restrict free movement and the guinea pigs may need to be housed singly after surgery. The caging, bedding and environmental enrichment need to be appropriate to prevent the tether becoming entangled and the wound contaminated. In addition, the bedding needs to be sange free.
The cannula is small which can promote blood clotting (larger cannulae can abrade the blood vessel wall). To prevent this, the cannula requires regular maintenance, (e.g. flushing with an anticoagulant).
Blood should be collected aseptically. 0.1 - 0.5 ml can be taken per sample and, depending on the sample volume and scientific justification, up to six samples can be taken over a two hour period. 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 skin in contact with the jacket should be checked for abrasion
- The jacket should be checked for tightness
- Wound sites should be checked for infection/bruising/swelling/haemorrhage
- The cannula should be checked for patency
- The weight of the guinea pig (for recovery work)
|Number of samples||Up to six samples may be taken in a two hour period, depending on sample volume.|
|Sample volume||0.1 - 0.5 ml|
|Equipment||23G - 25G cannula|
|Staff resource||One person is required to take the blood sample. Further staff resource is required for surgery, post-operative care for up to 5 days after surgery, and daily animal observations post-surgery.|
|Other||Guinea pigs should be at their pre-operative weight before blood sampling starts.|
- A good practice guide to the administration of substances and removal of blood, including routes and volumes.
- Gunaratna PC, Kissinger PT, Kissinger CB, Gitzen JF (2004), An automated blood sampler for simultaneous sampling of systemic blood and brain microdialysates for drug absorption, distribution, metabolism and elimination studies. Journal of Pharmacological and Toxicological Methods. 49(1), pp 57-64
- Lucas RL, Lentz KD, Hale AS (2004), Collection and preparation of blood products. Clinical Techniques in Small Animal Practice. 19(2), pp 55-62
- Guo Z, Zhou L (2003), Dual tail catheters for infusion and sampling in rats as an efficient platform for metabolic experiments. Lab Animal. 32(2), pp 45-48
- Impact of chronic catheterisation and automated blood sampling (Accusampler) on serum corticosterone and fecal immunoreactive corticosterone metablitues and immunoglobulin A in male rats.
- De Jong WH, Timmerman A, Van Raaij MTM (2001), Long term cannulation of the vena cava of rats for blood sampling: local and systemic effects observed by histopathology after six weeks of cannulation. Laboratory Animals. 35(3), pp 243-248
- Removal of blood from laboratory animals and birds.
- Kucharski J, Jana B (2003), The cannulation of the caudal caval vein through the femoral vein in the pig for endocrine research. Polish Journal of Veterinary Science. 6(2), pp 87-92
- Lichtenberger M (2004), Transfusion medicine in exotic pets. Clinical Techniques in Small Animal Practice. 19(2), pp 88-95