Scapular osteomyelitis in an immature domestic shorthair cat

Abstract

Case summaryA 12-week-old, male, domestic shorthair cat was presented with severe left thoracic limb lameness. Investigation included physical examination, diagnostic imaging with radiography and CT, histopathology and microbiological culture. Physical examination revealed a large, firm mass on the left scapula. Radiography and CT showed a monostotic spherical expansile bone lesion in the infraspinatus fossa of the left scapula. The histopathological description was a central acute suppurative osteomyelitis with reactive fibrosis and new bone formation at the periphery. Aerobic and anaerobic cultures were negative and the underlying cause of the osteomyelitis could not be identified. The use of broad-spectrum antibiotics for 8 weeks proved effective with full clinical recovery and no signs of relapse during the follow-up time of 8 months.Relevance and novel informationThis report describes the management and outcome of a rare case of osteomyelitis with severe deformation of scapular bone morphology in an immature cat that was treated successfully with full recovery of limb function and restored integrity of the scapula.

An uncommon case: feline tail post-traumatic osteomyelitis

“…Most of it report the OM cases in dogs (Dunn et.al., 1992), occasionally including cats, and seldom other species. Beside well described cases of OM in dogs and cats located in distal phalanges of the extremities (Šehić, 2000), there are occasional reports of OM in other rare locations like scapula (Viskjer and Rapp, 2016), jaw (Rodrigues de Farias, 2012), nasal bone (Johnson et.al., 2006), or pelvis (Doolitle, 2017). We found no report about tail OM either in dogs or cats.…”

“…Other skeletal involvement such as vertebral infections and discospondylitis are most often caused by a haematogenous spread from elsewhere in the body whereas OM of the jaw in cats is often associated with periodontal disease and caused by a broad range of bacteria, most of which are normal oral flora (Johnson et al, 2006). Haematogenous OM is uncommon in dogs and cats, and typically affects young animals (Viskjer and Rapp, 2016). Posttraumatic OM presents as spread of unrestricted infection from the infected soft tissue to the periostea, epiphysis, metaphysis and bone marrow.…”

“…Often cultures may contain more than one organism, and the presence of a gram-positive and gram-negative organism is quite common (Hatzenbuehler and Pulling, 2011). Staphylococcus is the most commonly cultured organism, isolated in up to 74% of bone infections reported in small animals (Bubenik, 2005), followed by Streptococcus, Escherichia coli, and Proteus species (Viskjer and Rapp, 2016).…”

“…Neglected bite wounds and abscesses, periodontal infection and chronic paronychia are common initiating cause of OM (Sia and Berbari, 2006). Normal, healthy bone in an immune-competent animal is highly resistant to infection, but injury and infection of adjacent soft tissue may induce a posttraumatic OM subsequent to a bite or scratch (Viskjer and Rapp, 2016). However, if the immune-competence of an injured animal is further compromised, as it is with many outdoor cats, the infection spreads easily affecting bone structures underneath inflamated soft tissue.…”

Sterile osteomyelitis in the ulnar diaphysis of a young indoor cat

“…It might be that this case could have a similar cause as the previously reported case of scapular osteomyelitis in a young cat. 13 As the lameness completely resolved, the owner declined further investigations. From our point of view, further imaging would have been ideal to document ongoing healing and to identify any deterioration in case of ongoing disease.…”