What illnesses affect rats? - briefly
Rats commonly contract bacterial infections (e.g., Salmonella, Streptobacillus), viral diseases (e.g., Sendai virus, rat coronaviruses), parasitic infestations (mites, fleas, helminths), and neoplastic conditions such as mammary tumors. Clinical signs include respiratory distress, diarrhea, weight loss, and palpable masses.
What illnesses affect rats? - in detail
Rats are susceptible to a wide range of pathogens that can affect multiple organ systems. Bacterial infections frequently involve the respiratory tract, gastrointestinal tract, and skin. Common agents include Mycoplasma pulmonis, causing chronic respiratory disease with nasal discharge and labored breathing; Streptobacillus moniliformis, the cause of rat‑bite fever, which produces fever, arthritis, and rash after a bite; Salmonella spp., leading to diarrhea, dehydration, and septicemia; and Leptospira spp., which may result in renal failure and jaundice.
Viral illnesses are prominent in laboratory and pet colonies. The sialodacryoadenitis virus produces swelling of the lacrimal and salivary glands, conjunctivitis, and transient fever. Rat coronavirus (RCV) induces enteric disease with watery diarrhea and weight loss. Sendai virus causes severe pneumonia, especially in immunocompromised individuals. These viruses spread rapidly through aerosol or direct contact and often persist in the environment.
Parasitic disorders affect both internal and external systems. Gastrointestinal helminths such as Hymenolepis nana and Syphacia spp. cause weight loss, anemia, and intestinal irritation. Protozoan infections like Giardia duodenalis produce watery stools and malabsorption. Ectoparasites—mites (Myobia musculinus), lice (Polyplax serrata), and fleas—induce pruritus, alopecia, and secondary bacterial skin infections.
Fungal agents are less common but can cause serious disease. Dermatophytes (e.g., Trichophyton mentagrophytes) lead to crusty lesions and hair loss. Systemic mycoses such as Candida or Aspergillus may develop in immunosuppressed rats, presenting with organ dysfunction and septicemia.
Metabolic and nutritional disorders appear when diet is inadequate or when physiological stress interferes with homeostasis. Vitamin C deficiency, though rare, can cause scurvy‑like symptoms: hemorrhages, joint pain, and impaired wound healing. Calcium deficiency results in osteomalacia and skeletal fragility. Excessive fat intake predisposes to hepatic lipidosis and obesity‑related cardiovascular strain.
Neoplastic conditions become more prevalent with age. Mammary adenocarcinomas, lymphomas, and sarcomas manifest as palpable masses, organ enlargement, or weight loss. Early detection relies on regular physical examination and imaging when available.
Common clinical signs across these diseases include:
- Respiratory distress (nasal discharge, wheezing, labored breathing)
- Gastrointestinal upset (diarrhea, vomiting, weight loss)
- Dermatologic lesions (alopecia, crusts, pruritus)
- Systemic signs (fever, lethargy, anorexia)
- Neurological abnormalities (tremors, ataxia)
Effective management requires accurate diagnosis through culture, PCR, serology, or necropsy, followed by targeted antimicrobial, antiviral, antiparasitic, or supportive therapy. Hygiene, quarantine of new arrivals, and vaccination where available reduce outbreak risk in both research facilities and household settings.