What diseases affect field mice? - briefly
Field mice are susceptible to bacterial infections such as Salmonella and Yersinia, viral agents including hantavirus and lymphocytic choriomeningitis virus, parasitic infestations by fleas, mites, helminths, and fungal diseases like dermatophytosis.
What diseases affect field mice? - in detail
Field mice are susceptible to a range of bacterial, viral, fungal, and parasitic agents that can cause morbidity and mortality in wild and laboratory populations.
Bacterial infections commonly observed include:
- Mycoplasma pulmonis – primary cause of murine respiratory disease; symptoms involve nasal discharge, sneezing, and bronchopneumonia. Transmission occurs through direct contact and aerosolized secretions.
- Yersinia pestis – agent of plague; fleas act as vectors, leading to sudden septicemia and hemorrhagic pneumonia. Outbreaks can decimate local rodent colonies.
- Salmonella spp. – produce enteritis and septicemia; spread via contaminated food, water, or fecal contact.
- Bordetella bronchiseptica – contributes to respiratory distress; often co‑infects with Mycoplasma, exacerbating clinical severity.
Viral pathogens affecting these rodents comprise:
- Hantaviruses – maintained in asymptomatic carriers but can cause hemorrhagic fever with renal syndrome in humans; mice shed virus in urine, feces, and saliva.
- Lymphocytic choriomeningitis virus (LCMV) – transmitted vertically and horizontally; leads to neurological signs and immunosuppression.
- Mouse adenovirus – produces conjunctivitis and hepatic lesions; spreads through bodily fluids.
Fungal diseases, though less frequent, include:
- Candida albicans – opportunistic overgrowth in immunocompromised individuals; manifests as oral and gastrointestinal candidiasis.
- Aspergillus spp. – inhalation of spores can cause pulmonary mycosis, especially in densely populated enclosures.
Parasitic infestations are diverse:
- Ectoparasites: fleas (e.g., Orchopeas spp.), ticks, and mites cause anemia, skin irritation, and act as vectors for bacterial and viral agents.
- Endoparasites: nematodes such as Heligmosomoides polygyrus and Syphacia muris reside in the gastrointestinal tract, leading to weight loss, diarrhea, and impaired nutrient absorption.
- Protozoa: coccidia (Eimeria spp.) produce enteric disease with bloody stools; infection intensity correlates with environmental contamination.
Clinical presentation varies with pathogen load and host condition. Respiratory signs dominate bacterial and viral infections; gastrointestinal disturbances predominate in parasitic and fungal cases. Mortality rates rise sharply when co‑infections occur, as synergistic effects compromise immune defenses.
Control measures focus on biosecurity, habitat sanitation, and targeted therapeutics. Antimicrobials (e.g., tetracyclines for Mycoplasma), antiparasitic agents (e.g., ivermectin for ectoparasites, benzimidazoles for nematodes), and antifungal drugs (e.g., fluconazole) are employed based on diagnostic confirmation. Vaccination programs exist for select viral agents in laboratory colonies but are not widely applicable to wild populations.
Understanding pathogen spectra, transmission dynamics, and clinical outcomes is essential for managing health risks in field mouse communities and preventing zoonotic spillover.