This archive report was first published on 3 May 2021.
Lab rats have been a crucial part of medical research for decades, helping scientists test the safety and efficacy of new medicines and vaccines. But have you ever wondered why lab rats are mostly white and not cats?
According to Jacques Kabaru, an associate professor at the University of Nairobi's School of Biological Sciences, lab rats are preferred for medical research due to their genetic similarity to humans. 'Mice and rats have similar genetics, anatomy, hormones, and physiology to humans, making them ideal models for researching on obesity, respiratory problems, cataracts, seizures, heart diseases, HIV, high blood pressure, and spinal injuries,' Kabaru explains.
Lab rats are also easy to handle, cost-effective in feeding and housing, and reproduce quickly, making them a valuable resource for scientists. 'Mice reproduce faster; in two months they are ready to get pregnant again,' Kabaru says.
The University of Nairobi's School of Biological Sciences has been breeding white mice and rats for research for over 50 years. The commonest strain used is the Wistar rat, which is kept and fed in well-lit and aerated rooms with a cage holding about 10 mice.
But why are lab rats mostly white and not cats? Kabaru explains that white mice and rats are easier to mark for identification and are less likely to develop genetic diseases. 'If you have a sister mating a brother in a small knit environment, then you are bound to get genetic diseases,' Kabaru says.
The University of Nairobi's animal house is equipped with the highest international standards, and the lab rats are kept in clean housing with their bedding changed often. 'The husbandry is very important, the cages they stay in are of the highest international standards, the food they eat is aflatoxin free,' Kabaru says.
It's not just the lab rats that are well-cared for; the animal house attendant, Joshua Oduor, ensures that the rats have enough water and food, and checks for any sick animals daily.
Lab rats have been used in various research studies, including testing the efficacy of diabetes drugs and parasitic diseases like sleeping sickness and malaria. 'When a drug is tested, you want to verify if it works or is poisonous, and this includes for diseases like cancer,' Kabaru explains.
The University of Nairobi's School of Biological Sciences breeds its own stock of lab rats, but sometimes borrows from the Kenya Medical Research Institute (Kemri) and the Kenyatta National Hospital. 'We donate some to them and this way we avoid genetic defects,' Kabaru says.
Lab rats are not just used in medical research; they are also used in psychological experiments. 'Mice and rats are social as human beings, and are useful in behavioural studies,' Kabaru explains.
So, the next time you hear about lab rats being used in medical research, remember that they are not just test subjects, but also play a crucial role in helping scientists develop new medicines and vaccines.
