Manual surgical monitoring techniques can be tedious for lab technicians as well as animals, given the multiple welfare checks needed per day plus the need for workers to update records accordingly. Further complicating matters, manual monitoring is generally done during daytime work hours, which causes researchers to miss out on valuable nighttime data points and activities. Fortunately, laboratories around the globe have a new tool at their disposal: implantable radio frequency identification (RFID) microchips. This innovative technology monitors rodents’ home cage temperature and activity, “hands-free.”
With RFID microchips, lab animals can now be monitored in a non-invasive, real-time, continuous manner, while housed either singly or in groups. In a recent five-day study, our team at Envigo collaborated with the technology company Unified Information Devices in attempt to both enhance the pre- and post-surgical monitoring of cardiac surgical models and improve animal welfare.
Six groups of rats and six groups of mice were implanted with standard RFID microchips via intraperitoneal injection. Rodents were assigned to either an MI or TAC group and housed in one cage per study group. A wealth of data was generated from this study, bringing to light the many ways RFID technology can provide for more effective animal monitoring.1. RFID microchips effectively monitor temperature 24/7
Over the course of the study, over two million data points were amassed for these rodents. Body temperature was assessed pre-surgery, during surgery and post-surgery over the five-day study period. Animals served as their own controls. Some animals were immediately recovered with post-surgery heat and others were placed on heat a few days after surgery. Temperature and activity were recorded 24/7 and as often as every 0.6 seconds. Data from the study could be viewed in real time and remotely.
Following surgery on the mice, their temperature dropped almost immediately after removal from surgical heating pads. Post-surgery heat significantly improved recovery time in mice and led to increased feeding and drinking. Heat was less important for rats’ post-surgery recovery, because of the rats’ larger body size. The study’s temperature data provided valuable insights into heat loss during surgery and post-surgery and how heat affects animal recovery times.
2. RFID technology provides real-time activity data around the clock
Animal cages were placed on reader plates that gathered information on the activity of specific animals based on their zone and their temperatures. An activity was scored when an animal moved from one zone to another. The study results showed that mice were not very active during the day, but once the lights were turned off at night, their activity increased substantially.
Mice activity also significantly decreased the first two days post-surgery. Mice that were recovered with heat were more active, fed and drank more, and had higher feces and urine output, reflecting their increased food and water intake. Rats recovered with heat were more active than rats recovered without heat.
Mice recovered with heat returned to control activity levels on Day 5 post-surgery, which was quicker than the animals recovered without heat. In rats, activity returned to control levels at Day 3 post-surgery. Without the RFID microchips, researchers would not have had nearly as much information about the rodents’ activity levels.
3. RFID microchips enhance the 3Rs by decreasing animal stress and improving survival rates while providing reliable data
Monitoring of temperature and activity via RFID microchips helps ensure that animals are being handled in accordance with the 3Rs. Once the RFID device is implanted, the need for manual handling to check temperature is obviated.
With help from RFID microchips, researchers now have access to reliable, quality data both pre- and post-surgery. This should reduce the likelihood of having to repeat a study.
Harness the power of RFID technology to benefit your latest study
As of July 2019, Envigo surgically modified rats can have RFID microchips with temperature monitoring implanted. Surgically modified mice can be implanted with RFID microchips, and temperature monitoring can also be requested.
For more information about this study, please refer to our whitepaper. If you need help selecting the most appropriate surgical model, check out our e-book on key considerations for choosing a rodent surgical model or schedule a consultation with one of our experts by contacting us.