What are the main causes of death in rats? - briefly
Rats commonly succumb to bacterial infections, neoplastic tumors, and respiratory diseases, while predation, physical trauma, and age‑related organ failure also contribute significantly to mortality.
What are the main causes of death in rats? - in detail
Rats succumb to a limited set of physiological and environmental threats that account for the majority of observed mortality. Understanding these factors is essential for researchers, veterinarians, and laboratory personnel who manage rodent populations.
Common natural and disease‑related causes include:
- Neoplastic diseases – malignant tumors of the mammary gland, lung, and liver develop spontaneously in older animals and frequently lead to death.
- Cardiovascular disorders – myocardial infarction, hypertension, and atherosclerosis arise with age or genetic predisposition, impairing circulation and causing fatal organ failure.
- Respiratory infections – bacterial agents such as Streptococcus pneumoniae and viral pathogens like Sendai virus produce pneumonia, edema, and hypoxia.
- Renal failure – chronic kidney disease, often secondary to hypertension or toxin exposure, results in electrolyte imbalance and uremia.
- Gastrointestinal complications – severe ulceration, ileus, and neoplasia of the gastrointestinal tract disrupt nutrient absorption and can precipitate septicemia.
Environmental and management‑related factors also contribute significantly:
- Heat stress – prolonged exposure to temperatures above the thermoneutral zone induces hyperthermia, dehydration, and organ collapse.
- Cold exposure – hypothermia compromises metabolic function, especially in young or immunocompromised individuals.
- Nutritional deficiencies – lack of essential vitamins (e.g., vitamin E, B12) or minerals (e.g., calcium) leads to metabolic bone disease, anemia, and immune suppression.
- Toxin ingestion – accidental consumption of pesticides, heavy metals, or improperly stored feed introduces acute hepatotoxic, nephrotoxic, or neurotoxic effects.
- Trauma – injuries from cage fixtures, handling, or inter‑animal aggression cause internal bleeding, fractures, and secondary infections.
Predatory stress and psychological factors, while less quantifiable, elevate cortisol levels and can exacerbate existing pathologies, accelerating mortality in susceptible individuals.
Effective mitigation requires regular health monitoring, appropriate environmental controls, balanced diets, and stringent biosecurity measures to limit pathogen introduction. Early detection of disease markers, coupled with prompt veterinary intervention, reduces the impact of these primary lethal agents.