What do mice die of? - briefly
Mice usually succumb to disease, predation, severe malnutrition, or extreme environmental conditions, with infections, tumors, and trauma being the most frequent lethal factors. Additional causes include dehydration, organ failure, and exposure to toxic substances.
What do mice die of? - in detail
Mice succumb to a range of lethal factors that can be grouped into biological, environmental, and experimental categories.
Pathogenic agents dominate natural mortality. Viral infections such as mouse hepatitis virus, lymphocytic choriomeningitis virus, and murine norovirus cause systemic disease and organ failure. Bacterial pathogens, including Salmonella spp., Staphylococcus aureus, and Pseudomonas aeruginosa, lead to septicemia, pneumonia, or wound infection. Parasitic infestations—Mycobacterium pulmonis (respiratory disease), Eimeria spp. (coccidiosis), and various ectoparasites—induce chronic debilitation and secondary infections. Fungal diseases, notably Candida spp. and Aspergillus spp., result in opportunistic mycoses under immunosuppressed conditions.
Neoplastic processes contribute significantly to death in aged colonies. Lymphomas, mammary adenocarcinomas, and hepatocellular carcinomas progress unchecked in the absence of therapeutic intervention, leading to organ dysfunction and cachexia.
Environmental stressors precipitate fatal outcomes. Extreme temperature fluctuations (hypothermia below 10 °C, hyperthermia above 35 °C) impair thermoregulation and cause cardiovascular collapse. Toxic exposure—heavy metals (lead, cadmium), pesticides, and contaminated feed—produces acute organ toxicity. Dehydration and malnutrition, often secondary to disease or inadequate husbandry, result in electrolyte imbalance and multi‑organ failure.
Predation and accidental injury affect free‑living and laboratory populations. Avian, reptilian, and mammalian predators inflict lethal trauma. Cage‑related hazards—entanglement, crushing, or escape into hazardous areas—cause fatal injuries.
In research settings, humane euthanasia constitutes a controlled cause of death. Approved methods (CO₂ inhalation, injectable barbiturates, cervical dislocation) are employed to terminate suffering or collect tissue samples, adhering to institutional animal care guidelines.
Collectively, these factors account for the majority of mouse mortality across wild, pet, and laboratory environments.