While mice, rats and other<unk>  are by far the most widely used<unk> s in biomedical research, recent studies have highlighted their limitations. For example, the utility of the use of<unk>  in testing for sepsis, burns, inflammation, stroke, ALS, Alzheimer’s, diabetes, cancer, multiple sclerosis, Parkinson’s disease and other illnesses has been called into question by a number of researchers. Regarding experiments on mice in particular, some researchers have complained that “years and billions of dollars have been wasted following false leads” as a result of a preoccupation with the use of these<unk> s in studies. Mice differ from humans in several immune properties: mice are more resistant to some toxins than humans; have a lower total neutrophil fraction in the blood, a lower neutrophil enzymatic capacity, lower activity of the complement system, and a different set of pentraxins involved in the inflammatory process; and lack genes for important components of the immune system, such as IL-8, IL-37, TLR10, ICAM-3, etc. Laboratory mice reared in specific-pathogen-free (SPF) conditions usually have a rather immature immune system with a deficit of memory T cells. These mice may have limited diversity of the microbiota, which directly affects the immune system and the development of pathological conditions. Moreover, persistent virus infections (for example, herpesviruses) are activated in humans, but not in SPF mice, with septic complications and may change the resistance to bacterial coinfections. “Dirty” mice are possibly better suitable for mimicking human pathologies. In addition, inbred mouse strains are used in the overwhelming majority of studies, while the human population is heterogeneous, pointing to the importance of studies in interstrain hybrid, outbred, and nonlinear mice. An article in The Scientist notes, “The difficulties associated with using<unk>  models for human disease result from the metabolic, anatomic, and cellular differences between humans and other creatures, but the problems go even deeper than that” including issues with the design and execution of the tests themselves. For example, researchers have found that many rats and mice in laboratories are obese from excess food and minimal exercise which alters their physiology and drug metabolism. Many laboratory<unk> s, including mice and rats, are chronically stressed which can also negatively affect research outcomes and the ability to accurately extrapolate findings to humans. Researchers have also noted that many studies involving mice, rats and other<unk>  are poorly designed, leading to questionable findings. One explanation for deficiencies in studies of<unk>  housed in laboratory cages is that they lack access to environmental agency and thus the ongoing freedom to make decisions and experience their consequences. By housing<unk>  under extreme impoverished conditions, these captive<unk> s bear diminished resemblance to humans or their wild conspecifics. Some studies suggests that inadequate published data in<unk>  testing may result in irreproducible research, with missing details about how experiments are done are omitted from published papers or differences in testing that may introduce bias. Examples of hidden bias include a 2014 study from McGill University in Montreal, Canada which suggests that mice handled by men rather than women showed higher stress levels. Another study in 2016 suggested that gut microbiomes in mice may have an impact upon scientific research.
Animal testing on rodents
Laboratory developed test
Animal testing on non-human primates
Animal testing on invertebrates
Aquatic toxicology databases
Functional molecular infection epidemiology
WHO model list of essential in vitro diagnostics
EPA list of extremely hazardous substances