Anemia

• Kidney/Renal disease
• Chronic disease (e.g., lengthy course of illness, lymphoma, leukemia)

Abdomen enlarged/bloated

• Bacterial or Viral illness
  
• Congestive Heart Failure
  
• Megacolon
  
• Tumor growth
• Pyometra
• Abscess
• Organomegaly (organ enlargement such as: spleen, liver)
• Obesity
• Clostridial enteropathy (e.g., Tyzzer’s in weaned rats)
• Pregnancy (see: Breeding Guide)
• Obesity

Ascites

• Right-sided Heart Failure
• Disease involving the liver
• Abdominal tumors
• Renal disease/failure

Inappetence/Anorexia

• Diseases of the mouth
• Malocclusion
• Poor diet
• Systemic disease
• Pain

Circling/Head Tilt

• Otitis media/interna (ear inflammation or infection)
• Pituitary tumor
  
• Brain abscess
• Meningitis (inflammation of the membrane that covers the brain and the spinal cord)
• Encephalitis (inflammation of brain parenchyma)

Diarrhea

• Antibiotic induced
• Environmental stress
• Dietary issues
• Endoparasites (e.g., helminths, protozoa)
• Liver disease

Eye lesions / bulging

• Cataracts
• Keratitis due to infection (e.g., coronaviruses)
• Corneal abrasions
• Luxation/subluxation
• Retrobulbar abscess

Facial Swelling

• Salivary gland swelling – Corona virus infections (e.g., RCV/SDAV)
• Abscessed lymph nodes
• Dental abscess
• Neoplasia (e.g., Zymbal’s Gland Tumor)

Hairloss (Alopecia)

• Alopecia (skin intact)
  • Barbering
  • Hereditary/Congenital/Age

• Alopecia (skin abraded, red, crusted, ulcerated)
  • Dermatitis
  • Ectoparasites

Itching/Scabs

• Allergies
• Bacterial/fungal infections of skin
• Endocrine diseases (e.g., Diabetes)
• High protein diet
• Parasites (e.g., mites, lice)

Lumps, large nodules

• Abscesses
• Cysts
• Tumors
• Seroma (subcutaneous lump/mass)¹
• Hematoma (subcutaneous lump/mass)¹

Paralysis

• Brain/Pituitary tumors (usually front leg paralysis/stiffness)
• Degenerative Radiculomyelopathy (hind limb paralysis)
• Degenerative Spondylosis (condition of the spine e.g., osteoarthritis)
• Stroke (usually one side and rapid onset)

Sneezing/Wheezing/Gasping

• Allergies
• Heart Failure (cardiomyopathy, congestive heart failure)
• Respiratory infections
• Respiratory irritants
• Stroke (usually one side and rapid onset)

Tail constrictions/Bumps/Necrosis

• Bacterial or Viral infections
• Degloved
• Poor Hygiene
• Ringtail
• Neoplasia (e.g., squamous cell carcinoma)

Urinary Bleeding/Discharge/Odor/Volume

• Bacterial infection
• Bladder stones
• Neoplasia
• Diabetes (increased amount of urine)
• Renal disease (increased amount of urine)

Vaginal discharge

• Pyometra (e.g., bacterial infection)
• Neoplasia (e.g., uterine / ovarian tumors)
• Dystocia (e.g., ineffective uterine contractions in birthing; a labor emergency!)

*Note: female rats normally experience estrus every 4-5 days (go into “heat” at fairly regular times- year round), they do not menstruate (shedding of / expelling blood).

Testicular Issues

• Neoplasia (e.g., firm mass felt in addition to testes)
• Cryptorchidism (e.g., one or both testes absent, or are retained permanently in the abdomen)

References

1. Keeble, E. J., & Meredith, A. (2009). BSAVA manual of rodents and ferrets.(pp.342), Quedgeley: British Small Animal Veterinary Association.
2. Keeble, E. J., & Meredith, A. (2009). BSAVA manual of rodents and ferrets.(pp.335-337), Quedgeley: British Small Animal Veterinary Association.