6 Simple Ways to Improve Rodent Surgical Outcomes & Results

Are you seizing every possible opportunity to improve your rodent surgical outcomes? During our educational webinar “6 Simple Tips That Will Significantly Improve Rodent Surgical Outcomes,” presenter Marcel Perret-Gentil, DVM, MS, University Veterinarian & Director of the Laboratory Animal Resources Center at The University of Texas, Antonio (UTSA), highlights simple ways to improve rodent surgical outcomes.

According to Perret-Gentil, “If you implement these relatively simple tips – I promise you – you will improve the outcomes of your surgery. You will improve animal care, animal welfare, and data.” So, to make these powerful promises come true, follow Perret-Gentil’s steps, which we consolidate for you below.

The 6 Steps

Acclimation
Aseptic Technique
Temperature Regulation
Hydration
Oxygen Supplementation
Non-Pharmaceutical Methods of Pain Control

Learning objectives:

Improve surgical outcomes that will lessen post-op morbidity and mortality

Improve data yield after rodent surgery

Be able to implement best principles into a rodent surgical program

1. Ensure Proper Acclimation Time to Improve Rodent Surgical Outcomes

Marcel Perret-Gentil emphasizes giving research rodents enough time to acclimate to the facility before conducting research. Why is this advice so essential? Because entering a new facility is very stressful for research animals. It’s exposing them to new sounds, lights, smells, bedding, food, and more! That type of drastic change requires an adequate adjustment period.

Perret-Gentil explains how when research animals experience high stress, their hormonal levels will skyrocket, making them physiologically abnormal. Additionally, stress affects healing. Hence, it’s imperative to give them time to acclimate to their new environment to let their hormone levels regulate before performing surgery! Ensuring that your research rodent is stable is crucial to mitigate unknown variables.

2. Use Aseptic Technique to Increase Successful Rodent Surgical Outcomes

First, let’s review the meaning of Asepsis. When something, such as surgery, is Aseptic, it is free from contamination caused by harmful bacteria, viruses, or other microorganisms. According to Perret-Gentil, there’s no such thing as “perfect” aseptic surgery. Simply, it is just not possible to eliminate all contaminants. However, through a series of rigorous protocols, it’s possible to come close to aseptic rodent surgery.

Why is it crucial to come as close to an aseptic surgery as possible? Because if you don’t, research animals are more likely to develop harmful and sometimes life-threatening and result-altering infections. Furthermore, as Perret-Gentil emphasizes, some contaminations can go unnoticed by the human eye (subclinical infections). And although disease in a research rodent isn’t always visible, it will still impact data.

Poor rodent aseptic surgery results in the following:

Delays to post-op normality

Physiological changes

Alterations in immunity

Affects data yield

Practical Tips on Proper Aseptic Technique

See the webinar for more details about these tips and how to achieve them with “Press’ n Seal (R).”

Surgeon prep in impermeable arm sleeves misted with disinfectant
Rodent surgical draping (sterile, adheres to skin, impermeable, transparent, traps body heat)
A sterilized and organized surgical area setup
Clean post-op recovery cage and bedding
Ensure the surgeon is not touching non-sterile parts with sterile gloves

3. Ensure Safe Temperature Regulation for Rodents

Perret-Gentil emphasizes the importance of temperature regulation during rodent surgery. As he explains, some investigators often overlook it. But the bottom line is, regulating rodent body temperature is essential for improving surgical outcomes. Why? Well, first, anesthetics used during surgery depress thermoregulation. Additionally, during surgery, vasodilation occurs, which causes more heat loss. Lastly, there are some serious risks associated with hypothermic rodents.

Hypothermia prolongs recovery. So, it could take longer for the rodents to recover from surgery. Also, it can lead to hypoventilation and a decrease in platelet function (which is critical to post-operative recovery and bleeding control). Furthermore, it can increase the risk of infection, mortality, and blood viscosity. And as Perret-Gentil points out, all of these issues affect data. Also, he highlights how the laboratory science community must strive for better veterinary care that avoids hypothermia.

4. Use Non-Pharmacological Pain Control for Better Results

What do you do when you have a throbbing headache? You probably reach for the medicine cabinet and take your favorite over-the-counter pain reliever. But there are other things you can do to manage your pain, separate from pharmaceutical options. The same goes for research rodents. Perret-Gentil emphasizes the importance of providing research subjects with non-pharmacological pain control.

Use Non-Pharmacological Pain Control for Better rodent surgical outcomes

What are some ways to mitigate pain for rodents without drugs? Well, fear and anxiety are proven to enhance the pain response. So, as Perret-Gentil explains, providing animals with a stress-free environment should be included in pain management programs. You can minimize stress by providing them with enrichment, such as shelters and nesting materials. If rodents have a place to hide and nest during recovery, it can reduce stress and enhance healing.

5. Hydration is Essential for the Best Rodent Surgical Outcomes

According to Perret-Gentil, hydrating rodents before surgery causes post-op mortality and morbidity rates to go down. Hence, Perret-Gentil’s research program at UTSA requires all investigators to hydrate rodents with Lactated Ringer’s solution or normal saline before surgery. Perret-Gentil recommends that all research programs that perform surgery on rodents should follow suit.

6. Oxygen Supplementation is a Must

Anytime you’re administering anesthesia, it’s crucial to monitor oxygen levels. As you deliver anesthesia, especially injectable anesthesia, oxygen levels can drop dangerously. The higher the dose, the lower the oxygen drops. Decreased oxygen levels can damage the rodent’s major organs, including the brain, heart, and liver. Hence, supplementing oxygen during surgery is an excellent way to ensure the best outcome. Furthermore, at UTSA, providing oxygen to rodents during surgery when administering injectable anesthesia is required.

How to Measure the Success of Your Rodent Surgical Outcomes

Accurately measuring the success of your rodent surgical outcomes is essential for the overall improvement of your research program. According to Perret-Gentil, if you consider the survival of research rodents the only factor for success, you’re not grasping the whole picture. Watch the video below to learn about other ways to measure the success of rodent surgical outcomes.