Surgery - Rodent Blood Loss (Informational Sheet)

Informational Sheet: The IACUC has provided a set of guidance documents (Policies, Guidelines, and Informational Sheets) for use when planning animal procedures at the University of Iowa. Informational Sheets provide information about frequently asked questions and represents guidance for best practices. Deviation from the recommendation(s) does not require specific justification.

Purpose: The purpose of this document is to provide guidance on estimating surgical blood loss for use in IACUC-approved Animal Protocols.

An animal’s total blood loss should be estimated post-operatively.

• No more than 1% of an animal’s body weight should be lost in a 24 hour period (200g Rat is 2ml of blood).
•  If blood loss exceeds 1% of an animal’s body weight, replacement fluids should be given and OAR veterinary staff should be contacted.
• When total fluid loss is estimated after surgery an equal volume of commercial (pharmaceutical grade) sterile saline for injection (NaCl), lactated ringer’s solution, or other physiologic appropriate sterile fluid may be given subcutaneously.
  • Subcutaneous injections can be administered with a syringe in areas of loose skin i.e., the interscapular region.

Refer to Table 1 for the blood volumes associated with saturation of common hemostatic tools used in rodent surgery. As an example, 25 saturated cotton applicator tips would exceed the blood loss limit of a 200g rat.

Table 1:  Blood volumes associated with saturation of common hemostatic tools used in rodent surgery

Last reviewed by the IACUC: 2/14/2024