Veterinary Systemic Pathology Online

H-B02 - Cervical lymphadenitis (lumps) - Lymph node - Guinea pig

Morphologic Diagnosis:   Lymph node, cervical (per contributor): Lymphadenitis, necrosuppurative, chronic, focally extensive, severe (abscess), with cellulitis, guinea pig (Cavia porcellus), rodent

Etiologic Diagnosis:   Streptococcal lymphadenitis

General Discussion:

• The most common cause of cervical lymphadenitis in guinea pigs is Streptococcus equi subsp. zooepidemicus, Lancefield’s group C, a gram-positive encapsulated coccus that produces beta hemolysis on blood agar plates
• Occasionally, cervical lymphadenitis is caused by Streptobacillus moniliformis
• Females are more susceptible to the disease than males
• Stress increases susceptibility to infection

Typical Clinical Findings:

• The presence of bilaterally enlarged cervical lymph nodes in otherwise healthy guinea pigs is the usual and only sign
• The acute septicemic form causes depression, anorexia, pyrexia, or sudden death
• Torticollis is seen with middle and inner ear infections
• Dyspnea, cyanosis, and nasal/ocular discharge occur with pneumonia