SOP 7.4 - Rodent Post-operative Care (Mice)

University Animal Care Committee Standard Operating Procedure

Document No: 7.4

Subject: Rodent Post-operative Care (Mice)

Date Issued: July 23, 2015

Revision: 2

Location: Queen’s University

Responsibility: Principal Investigators, Research Staff, Veterinary Staff

Purpose: The purpose of this Standard Operating Procedure (SOP) is to describe the common protocol for post-operative care of rodents (Mice).

1. Introduction and Definitions:

It is the researcher's responsibility to ensure that adequate post-operative / post-anesthetic care is provided. The individual providing post-operative care must be trained appropriately.

It is important to note that these guidelines are MINIMUM STANDARDS ONLY.

An uneventful recovery and a healthy animal are desirable both from the researchers’ perspective and from the standpoint of animal welfare. Healthy animals provide more reliable data and decrease cost of treatment. The type of care required during the recovery period depends on two major factors. The first is the stage of recovery; more intensive care is required until the animal regains full consciousness. The second is the degree of invasiveness of the surgical procedure and the probability of post-operative complications. Postoperative care begins immediately following surgery and can extend up to 10 days. These factors must be considered together when formulating a plan for recovering an animal from anesthesia.

The goals of this SOP are to provide guidance:

  • for a rapid, smooth and minimally painful recovery
  • to reduce the likelihood of complications
  • to identify and correct, as quickly as possible, any complications that arise

 

Abbreviations

subcutaneous SC, intravenous IV, intraperitoneal IP, intramuscular IM, per os PO

 

2. Materials:

*All drugs, fluids, suture material and autoclaved items cannot be used if passed their expiry date*

  • Heat source
  • Oxygen/induction chamber
  • Paper towel, large gauze, small towel
  • Clean recovery cage
  • Eye lubricant and sterile swabs
  • Lactated Ringers solution or 0.9% sodium chloride
  • Hydrogel, fruit, or moist chow
  • Weigh scale
  • Surgical log book, cage cards

3. Procedures:

  • Weigh and record the animal’s weight on the day of surgery. Record the surgical procedure, all injections and any other standard procedure on the cage card. This information must also be included in the surgical log book (if used). Calculate the animal’s 15% BW loss and record this on their animal card for quick access later on.
  • Provide surgical analgesics as indicated in the protocol (typically for 72 hours post-surgery). It is recommended the initial dose is given shortly before surgery, for preemptive analgesia. Surgical patients can develop a heightened sensitivity to pain if it is left untreated. Neuropathways communicate pain sensations from the surgical site to the brain. Once that pathway is well worn, postsurgical pain can become more challenging to alleviate. Pre-emptive pain management helps patients avoid this scenario.
  • Once the surgical procedure is complete and anesthesia has been discontinued (if recovery surgery), administer 30ml/kg of room temperature Lactated Ringer’s solution or 0.9% sodium chloride SC. Place the animal on a paper towel, gauze or towel in a clean, dry cage free from other animals. The paper towel will prevent the animal from inhaling bedding during recovery.
  • Place half the cage on top of a heat source to facilitate maintenance of average normal body temperature; alternatively, suspend a heat lamp above half the recovery cage.
  • Observe the following every 5 minutes until the animal regains its righting reflex. Do not leave unattended.
    • Respiration: ensure that the animal continues breathing and does not show signs of respiratory distress such as increased (laboured) respiratory rate or rapid shallow breaths. If this occurs, place the animal in the induction chamber with just the oxygen flowing until normal rate and depth of breathing occurs.
    • Coloration of eyes for albinos (the eye colour should remain red – opaque or blue-tinged indicate distress).
    • Color and moisture of the mucous membranes – these should be pink and moist with a capillary refill time of < 2 sec.
    • Temperature: palpate the extremities (feet or tail) and/or take a rectal temperature to insure that temperature does not go outside of physiologic parameters.
  • Until the blinking reflex has returned, ensure eye lubricant is instilled.
  • If recovery is >5 minutes turn animal every 5 minutes. This stimulates the animal and also alternates the side of the chest (and lung) which the animal is laying on, thereby facilitating respiration.
  • Put a measured amount of food, fruit and/or hydrogel at the bottom of the cage. Alternatively, moist chow can be provided during the post-operative period to encourage appetite and facilitate hydration.
    *Moist chow: fill a small bowl or petri dish ¾ full with warm water and top up with a few (2-3) food pellets. Let sit for 10 minutes to allow water to be absorbed before placing in the animals cage.*
  • Only return animals that have recovered their righting reflex and are ambulatory to an animal room or cage-mates.
  • Examine animal daily for signs of grooming, general appearance, posture and locomotor activity. If any signs of dehydration occur (ruffled coat, sunken eyes, prolonged skin tenting), administer 30 ml/kg of sterile Lactated Ringer’s solution or 0.9% sodium chloride SC daily until the animal’s condition improves.
  • Ensure the animal is eating, drinking and eliminating normally.
  • Measure and record post-operative body weight daily, for a minimum of three days.
  • All procedures and drugs must be recorded on cage cards. A surgical logbook is recommended, easily accessible by the veterinarian team (e.g. stored in an anteroom or treatment room). However, if all the information found in the book is recorded on the cage card, the Principal Investigator can forego this secondary documentation. General parameters to be recorded for rodent surgery includes:
    • Sx (front of card),
    • baseline and post-op Day 1, 2, 3 weight,
    • injectable anaesthetics (dose, rate, frequency),
    • all pre-op and post-op analgesics and fluids (dose, rate, frequency).
  • Any irregularities in recovery must be brought to the attention of the clinical veterinarian. Continued weight loss, dehydration and lethargy are NOT acceptable. Refer to the Humane Interventions within the Animal Use Protocol (and the veterinarians) for guidance.
  • Monitor animal daily for signs of surgical complications such as (but not limited to) pain, paralysis, or seizures.
  • Examine the surgical site daily for signs (such as redness, swelling or discharge) of inflammation, infection, and/or dehiscence for at least 5 days. Apply antibiotic ointment to incision as required.
  • Remove the sutures or staples after 7 to 10 days, or as per protocol.
     
  • It is important to remember that the above represents minimum standards only.  Animals experiencing complications require more frequent monitoring and care.

Date New Version
02/28/19 Triennial Update 
05/23/19 Update
12/06/21 Updated SOP format

SOP 7.4 - Rodent Post-operative Care (Mice)

Download SOP 7.4 (PDF 92 KB)