Overview and Clinical Importance
Pasteurellosis is one of the most significant bacterial diseases affecting domestic rabbits, caused by Pasteurella multocida. This multisystemic disease is highly prevalent, with 30-90% of apparently healthy rabbits being asymptomatic carriers. Understanding pasteurellosis is critical for the NAVLE as it represents a common clinical challenge in rabbit medicine and has important zoonotic implications for veterinarians and pet owners.
| Clinical Form |
Clinical Signs |
Key Features |
| Upper Respiratory Disease (Snuffles) |
Serous to mucopurulent nasal discharge
Sneezing, snorting
Matted fur on forepaws
Nasal stridor |
Most common manifestation. Rabbits wipe nasal discharge with forepaws creating characteristic matted fur. May progress to sinusitis and pneumonia. |
| Conjunctivitis and Dacryocystitis |
Mucopurulent ocular discharge
Conjunctival hyperemia
Epiphora with facial scalding
Nasolacrimal duct obstruction |
Second most common manifestation. Chronic epiphora leads to stenosis of nasolacrimal ducts. May occur independently or with rhinitis. |
| Pneumonia |
Dyspnea, tachypnea
Moist rales on auscultation
Anorexia, depression
May die acutely without signs |
Can be acute or chronic. Chronic pneumonia often asymptomatic in caged rabbits with minimal respiratory demands. Radiographs show cranioventral consolidation and abscesses. |
| Otitis Media and Interna |
Head tilt (torticollis)
Rolling, circling
Nystagmus
Ataxia, loss of balance |
Infection spreads from nasopharynx via eustachian tube. Tympanic bullae filled with inspissated pus. Occurs in approximately 15% of rabbits with otitis media when vestibular apparatus involved. |
| Subcutaneous Abscesses |
Firm subcutaneous swellings
Thick, creamy, caseous exudate
May have draining tracts
Most common on head and shoulders |
Result from contaminated wounds, bite injuries, or hematogenous spread. Rabbit abscesses are thick-walled and do not drain well. Surgical excision en bloc is preferred over drainage. |
| Genital Infections |
Females: Serous to mucopurulent vaginal discharge, metritis, pyometra, infertility, abortion
Males: Orchitis, epididymitis, decreased fertility, enlarged firm testicles |
Transmitted venereally. Infected does may transmit to offspring during birth. May present as reproductive failure in breeding operations. |
| Septicemia |
Peracute death without premonitory signs
Depression, anorexia
Fever, hypothermia |
Secondary to pneumonia or rhinitis. Post-mortem findings: serosal and endocardial hemorrhages. Type D strains more commonly cause septicemia. |
Etiology
Organism Characteristics
Pasteurella multocida is a Gram-negative, non-motile, non-spore-forming coccobacillus belonging to the Pasteurellaceae family. The organism is pleomorphic and facultatively anaerobic with fermentative metabolism.
Capsular Types and Virulence
P. multocida strains are classified into five capsular serogroups (A, B, D, E, F) and 16 somatic serotypes. In rabbits: