• Too much blood collected at any one time may cause hypovolemic shock, physiological stress and even death. If smaller volumes are collected too frequently, anemia may result.
• As a general rule, 10% of the total blood volume can be collected at one time every 2-4 weeks, or 1% at more frequent intervals of 24 hours or more. The total blood volume can be calculated as approximately 7.5% of body weight.
• The estimated volume at exsanguination is approximately half of the total blood volume.

EXAMPLE

Average Adult Weight	Total Blood Volume	Maximum Sample in ml every 2-4 Weeks	Estimated Volume at Exsanguination
100 gm	7.5 ml	0.75 ml	3.75 ml

• An equal volume of warmed saline is recommended as fluid replacement if maximum blood volume is collected from rodents.
• Use aseptic technique.
• To improve vasodilation effects in rodents, it is helpful to warm the entire patient. This can be accomplished in 10-15 min at 40^o C with a heat lamp or a special commercially available warming chamber. Care should be taken to prevent overheating.
• Physiological effects of the anesthetics, such as hypotension, can make blood collection difficult in rodents. The choice of anesthetic should be made in consultation with a LARC Veterinarian.
• If not experienced in blood collection techniques, trainingtraining is recommended. If you have questions or comments about any of the above techniques, contact an LARC veterinarian at 476-2204.

Collection Site	Advantages	Disadvantages
Orbital Sinus or Plexus	Large quantities of blood can be collected	Anesthesia is required Requires training
Cephalic Vein	Anesthesia not required	For collection of small quantities of blood only
Lateral Saphenous Vein	Anesthesia not required Excellent technique for serial blood sampling Small – moderate quantities of blood can be collected	Requires training Some specialized equipment needed
Anterior Vena Cava	Large quantity of blood can be collected	Requires anesthesia Requires training Risk of cardiac tamponade
Cardiac Puncture	Maximum volume of blood can be collected	Requires deep anesthesia Non survival procedure