DISEASE SUMMARY PAGE

Osteomyelitis in Lagomorphs and Cranes

Summary Information
Diseases / List of Bacterial Diseases / Disease summary
Alternative Names  
Disease Agents
In Lagomorphs
  • Various bacteria, particularly Pseudomonas spp. (B602.35.w35) also Pasteurella multocida. (B600.16.w16)
  • Following either traumatic injury or surgery, associated with avascularity of bone, contamination of the wound (more than 105 organisms per gram tissue) and a suitable environment - e.g. a haematoma. (B602.35.w35)
  • Dental disease, particularly periapical abscesses. (B600.8.w8)
    • Malnourishment can exacerbate abscessation. (B600.8.w8)
  • Secondary to Ulcerative Pododermatitis in Lagomorphs. (B600.9.w9)
In Cranes
Infectious Agent(s)
Non-infectious Agent(s) --
Physical Agent(s) --
General Description
Clinical signs
In Lagomorphs
  • In a rabbit following fracture repair: fluctuant swelling of the foot, inability to bear weight on the affected foot. On incision of the swelling, thick, partially inspissated pus was released. The fracture failed to heal despite wound flushing and appropriate systemic antibiotics. (J4.185.w7)
  • Mandibular swelling, bony. (J196.70.w1)

(B602.35.w35)

In Cranes
  • In birds, usually no sign of systemic illness, but failure of fracture healing, with the fracture site filling with purulent, caseous material while the ends of the bone become sclerotic. (B12.42.w5)
Pathological findings
In Lagomorphs

Gross pathology

  • Affected mandible grossly and irregularly enlarged, containing a 2.5 cm diameter well-circumscribed holly bony mass, the inner wall of which was lined with inspissated pus, and a fistulous tract through the bone. (J196.70.w1)

Histopathology

  • In a rabbit following fracture repair: 
    • Fracture site abscessation, extending into the medullary cavity of the affected metatarsal, with little overlying cellulitis. (J4.185.w7)
  • In a rabbit with mandibular osteomyelitis: hollow bony mass with a fibrous capsular wall, acute and chronic inflammatory cells and inner degenerative heterophils. Numerous irregular exostoses with degenerative (lytic) changes. Throughout the affected mandible, fibrosis and inflammatory cell infiltration. (J196.70.w1)
Further Information
Susceptibility
In Lagomorphs
  • Open fractures are more likely to develop infection leading to osteoarthritis in rabbits than in most other species. (B601.17.w17, B602.35.w35)
  • Compromised blood supply to the bone increases the risk of infection. (B602.35.w35, J4.185.w7)
In Cranes
  • In general, bacterial diseases are seen in cranes which are predisposed to infection due to population or environmental stressors. (B336.20.w20)
Transmission
In Lagomorphs
  • Infection may be from gross contamination or blood-borne spread from another site of infection in the rabbit. (B602.35.w35, J4.185.w7)
In Cranes
  • Open fractures may become contaminated. (B115.8.w4)
  • Spread of infection from soft tissues in cases of Bumblefoot. (B115.8.w4)
Diagnosis
In Lagomorphs
  • Clinical signs.
  • Radiographic findings.
    • In osteomyelitis of the mandible, bony proliferation around central osteolytic areas. (J196.70.w1)
    • Periosteal reaction and osteolysis; sometimes an involucrum. (B602.35.w35)
    • Radiography is important to show the extent of bone (and joint) involvement and destruction. (B600.8.w8)
      • The prognosis is poor if osteomyelitis affects more than one limb. (B600.8.w8)
  • Culture of pus and sensitivity testing is required. (J4.185.w7)
    • Send samples for both aerobic and anaerobic culture. (B602.35.w35)
  • Differential diagnosis for dental-related facial osteomyelitis swellings includes neoplasia. (B600.8.w8)
In Cranes
  • On radiography, initially the bone shows a hazy structure and roughening of the trabecular outline. Later, there is simultaneous radiographic evidence of bone resoption and formation of reactionary bone. (B115.8.w4)
  • There may be raising of the periosteum, with formation of reactive bone under this. (B115.8.w4)
  • There may be obvious areas of osteolysis, particularly in association with a foreign body - this may be e.g. an intramedullary pin or a bone screw. (B115.8.w4)
  • If the infection is spreading, there may be an increase in the size of the area of osteolysis, an active periosteal response, loss of joint space, or evidence of soft tissue swelling. (B115.8.w4)
Treatment
In Lagomorphs
  • Aggressive treatment is required; treatment of osteomyelitis in rabbits appears to be more difficult than in most other species and is not always successful. (B601.17.w17, B602.35.w35, N12.38.w1)
  • Surgical drainage and debridement followed by appropriate antibiotic treatment. (B602.35.w35, J196.70.w1)
    • Infected bone and any foreign bodies (including elongated tooth crowns, if these are penetrating tissue) must be removed, as well as infected tooth roots in osteomyelitis associated with apical abscesses. (B600.8.w8)
    • All sinuses and tracts must be thoroughly explored to detect deeper connecting abscesses. (B600.8.w8)
    • Antibiotic treatment should be based on culture and sensitivity, using an antibiotic which is effective against the causal agent and reaches therapeutic levels in the affected tissues. (B600.8.w8)
    • Antibiotic-impregnated beads, containing appropriate antibiotics at appropriate concentrations, may be implanted under sterile conditions. (B602.35.w35)
      • This provides a high concentration of antibiotic at the required site. (B600.8.w8)
      • As an added advantage, some owners may find the stitched-up wound more aesthetically pleasing than an open cavity which is receiving topical treatment. (B600.8.w8)
      • Note: care is required. If the abscess capsule is not intact (i.e. the abscess is not fully walled off), there may be leakage of antibiotic into the surrounding tissues and thereby the systemic circulation. If this occurs, the usual considerations apply regarding possible effects of antibiotics on the rabbit's gut flora. (V.w65)
  • Repeated surgery may be required. (N12.38.w1)
  • Amputation may be an option if extensive bone destruction affects one limb only. (B600.8.w8)
    • Note: following amputation, there is an increased risk of development of ulcerative pododermatitis in the remaining limbs, due to increased pressure. (B600.8.w8)
  • Improve general health by good husbandry including a good diet, companionship, comfortable bedding and appropriate exercise opportunities. (B600.8.w8)
In Cranes
  • Antibiotics, chosen based on culture and sensitivity testing (or anti-fungals if culture indicates fungal infection). (B115.8.w4)
    • Antibiotics commonly used in cranes are listed in Drugs used in the treatment of Cranes
    • Successful treatment can be monitored radiographically as cessation of osteolysis and gradual return of normal bone structure.
    • Possible complications include delayed fracture union and development of bone sequestrae. (B115.8.w4)
Prevention
In Lagomorphs
  • Ensure strict sterile technique during orthopaedic surgery, as well as careful tissue handling, good haemostasis and good anatomical closure. (B602.35.w35)
Associated Techniques
Host taxa groups /species
Disease Author Dr Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referees John Chitty BVetMed CertZooMed MRCVS (V.w65)

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