Rhinitis in Rabbits

See also:

• Pasteurellosis in Lagomorphs
• Bordetella bronchiseptica Infection in Hedgehogs, Bears and Lagomorphs
• Staphylococcosis (with special reference to Waterfowl, Hedgehogs, Bears and Lagomorphs)

• Usually Pasteurella multocida, but sometimes other bacteria including Bordetella bronchiseptica, and Staphylococcus aureus. (B600.13.w13, B602.17.w17)
  • Infection with Bordetella bronchiseptica may be asymptomatic but act as a predisposing factor for Pasteurella multocida infection. (B602.17.w17, J60.6.w1)
  • Some strains of Bordatella bronchiseptica are more pathogenic. (B602.17.w17)

Additional factors include:

• Sudden fluctuations in environmental temperature.
• High ammonia levels (associated with poor sanitation and/or feeding of diets too high in protein).
• Stress.
• Low humidity - e.g. in centrally heated houses - with associated increased dust particles in the air.
• Cigarette smoke or aerosols which may damage/irritate the respiratory mucosa. 

(J60.6.w1)

• Bordetella bronchiseptica (Bordetella (Bacteria Genera))
• Pasteurella multocida
• Staphylococcus aureus

• Ventilation - inadequate (Physical Factors Summary)
• Temperature - high ambient (Physical Factors Summary)
• Temperature - low ambient (Physical Factors Summary)

Clinical signs

• Repeated sneezing and snorting.
  • Exudate may come from the nares at this time.
• Less commonly also coughing (rare in rabbits).
• Nasal discharge, initially serous and later mucopurulent - thick and white, later yellow.
  • Crusts of discharge may be found on the skin around the nose.
• Ocular discharge may be present.
• Wiping of the nose with the forepaws.
• Matting and discolouration of the fur on the forepaws.
  • Check the paws if no nasal discharge is visible, since it may have been wiped off. (B601.7.w7)
• Noisy respiration - nasopharyngeal noise which may be described as "wheezing". 
• Dacrocystitis. (J60.6.w1)
• Sometimes conjunctivitis. (B602.17.w17)
• Anorexia.
  • This may be associated with problems of breathing while eating, or possibly related to a decreased sense of smell.
• Ungroomed coat due to problems breathing while grooming.
• Clinical pathology: heterophilia may be noted with acute infection, or leucopaenia with chronic infection. (B601.7.w7)

(B600.13.w13, B601.7.w7, B602.17.w17, J60.6.w1, P3.2000b.w2)

Pathological findings

• URT: 
  • Nasal cavity and sometimes paranasal sinuses filled with pus in advanced disease; this becomes inspissated. Mucous membranes ulcerated, infected turbinates atrophied and eroded (osteomyelitis).
  • In acute disease, mucosal oedema and inflammation. (B602.17.w17)

(B600,13.w13)

Susceptibility / Transmission

• Young, recently acquired rabbits may develop disease having been infected at their breeding establishment then subjected to the stresses of weaning, transport and change in husbandry routine. (B600,13.w13)
• Increased susceptibility where a rabbit is kept in a shed or outhouse with several other rabbits. (B600,13.w13)

Diagnosis

• Clinical signs are suggestive, also consider the rabbit's history regarding susceptibility and transmission. (B600,13.w13)
• Auscultation of the trachea -  rales and rattles. (B602.17.w17)
• A deep nasal swab should be taken and sent for bacteriological culture and sensitivity testing. Insertion of the swab will generally require sedation or anaesthesia. (B600,13.w13)
  • Swab both nares. (B601.7.w7, B602.17.w17, J60.6.w1)
  • Insert at least 1 cm into each nares, further if possible (1 - 4 cm). (B601.7.w7, B602.17.w17)
  • A small swab is required, such as a no. 4 calcium alginate swab. (B601.7.w7, B602.17.w17)
  • For Pasteurella multocida, immediately inoculate onto blood agar and incubate in aerobic or microaerophilic conditions for a minimum of 48 hours. (B601.7.w7)
• Visual examination plus radiography to diagnose any underlying dental problems. (B600,13.w13)
• Radiography can be used to assess nasal structures as well as the teeth. Look for any erosion of the ethmoturbinates, or opaque conchal sinuses indicating exudate. Note: a periapical abscess or foreign body may be the cause of bacterial infection and turbinate erosion; finding exudate and erosion does not rule out these diseases. (B600,13.w13)
  • Careful positioning is important. (B602.17.w17)

Differential Diagnoses

• Differential diagnoses include dental disease (particularly in older pet rabbits), nasal foreign bodies (Nasal (and other URT) Foreign Bodies in Lagomorphs), and Myxomatosis (especially if aerosol-spread). (B600,13.w13)

Treatment

• Antibiotic therapy based on culture and sensitivity testing if possible. (J60.6.w1)
• For Pasteurella multocida, usually one of the following:
  • Enrofloxacin (B601.7.w7, B602.17.w17) 10 mg/kg once daily. (J60.6.w1) 5 mg/kg subcutaneously twice daily for 14 days; in chronic infection 5-10 mg/kg orally every 12 hours for as long as 2-3 months. (B602.17.w17)
  • Chloramphenicol. (B601.7.w7, B602.17.w17, J60.6.w1) 50 mg/kg orally twice daily. (B602.17.w17)
    • Treatment for 2-3 months may be needed. (B602.17.w17)
  • Gentamicin. (B601.7.w7, J60.6.w1)
  • Tetracycline (B601.7.w7, B602.17.w17), 30 mg/kg once daily. (J60.6.w1)
  • Trimethoprim-Sulphonamides (B601.7.w7, B602.17.w17) 30 mg/kg twice daily. (J60.6.w1)
  • Penicillin G. (B601.7.w7) 
    • 400 IU/kg subcutaneously once daily for 14 days then every 48 hours for two weeks or more. (B602.17.w17)
  • Ciprofloxacin 20 mg/kg orally once daily for five days. (B602.17.w17)
• For Bordatella bronchiseptica infection, appropriate antibiotic therapy is needed. (B602.17.w17)
• Note: consider the flora of the rabbit's gut when choosing an antibiotic. Dysbiosis is less likely to occur with Trimethoprim-Sulphonamides, fluroquinolones (e.g. Enrofloxacin), Chloramphenicol or tetracyclines. If penicillin is to be used, this side-effect is less likely if the drug is given parenterally rather than orally. (B602.17.w17) 
  • If the rabbit develops diarrhoea or anorexia during antibiotic treatment, stop treatment with that drug and try a different antibiotic. (B602.17.w17)
• Adjunct therapy: See: Treatment and Care
  • Analgesics as required. (J60.6.w1)
  • Fluid therapy as required. (J60.6.w1)
  • Ensure a good diet. (J60.6.w1)
  • Vitamin C. (J60.6.w1)

• Environmental Assessment
• History & Documentation
• Physical Examination of Mammals
• Necropsy of Mammals
• Imaging in Lagomorph Diagnosis and Treatment
• Clinical Pathology of Lagomorphs
• Treatment and Care
• Environmental and Population Management
• Preventative Medicine for Mammals
• Chapter 2 - B36 Field Manual of Wildlife Diseases - Specimen Collection and Preservation
• Chapter 3 - B36 Field Manual of Wildlife Diseases - Specimen shipment
• Appendix A - B36 Field Manual of Wildlife Diseases - Sample specimen history form

• Oryctolagus cuniculus domesticus - Domestic European rabbit