In this issue – June 2011

Computer model predictions and field observations of anthelmintic resistance in sheep · Dangers of off‐label use of barium selenate · Elbow luxation in dogs and cats · Prognosis of joint infections in adult horses · Omentalisation for mediastinal abscess in a dog · Adenoviruses in lizards     

Retrospective study of 60 cases of feline lymphosarcoma

Objective To characterise epidemiological and clinical findings, and diagnostic procedures undertaken, in cats with lymphosarcoma at a veterinary teaching hospital.
Design Retrospective case study.
Procedure Hospital records were reviewed for 7159 cats, sick or healthy, examined during a 10-year period (1984 to 1994). Sixty cats with lymphosarcoma were identified and classified by anatomical location of the tumour. Data on breed, age, sex, clinical signs and diagnostic procedures were collated.
Results The prevalence of feline lymphosarcoma in the hospital population was 0.84%. Siamese cats appeared predisposed to lymphosarcoma but other purebreds were not. Males were somewhat overrepresented amongst affected cats. Similar numbers of cases (12 to 18) were seen in each of the four anatomic categories (multicentric, mediastinal, alimentary and extranodal). Cats with mediastinal lymphosarcoma were mostly young and Siamese. Clinical signs in affected cats were varied, usually multiple and often nonspecific. Two of 22 cases tested positive for feline leukaemia virus antigen in blood and 6 of 13 were positive for feline immunodeficiency virus antibody.
Conclusions Extranodal lymphosarcoma seemed more prevalent in this study than reported elsewhere. Siamese cats in the study population may have had a genetic predisposition to lymphosarcoma. Limited evidence suggested feline leukaemia virus may be less important, and feline immunodeficiency virus more important, in the local population than indicated in overseas reports. Additional studies are needed to investigate breed predisposition and feline leukaemia virus and feline immunodeficiency virus status in Australian cats with lymphosarcoma.     

Bacterial Culturing for Prediction of Postoperative Complications Following Open Fracture Repair in Small Animals

Swab specimens for bacterial culturing were obtained from 82 consecutive dogs and 13 cats undergoing open reduction and internal fixation of 110 fractures. Bacteria were isolated from 51 wounds. When the data were analyzed by stepwise logistic regression, it was found that bacterial contamination of wounds was associated most often with open fractures and with tibia or radius/ulna fractures. Contaminated wounds were five times more likely to develop complications than those without bacterial contamination. Regardless of results of bacterial culturing, postoperative complications developed significantly more often in animals that were febrile (>39.4° C [103° F]). Postoperative complications did not develop in animals that did not have bacterial contamination of wounds and were not febrile.     

Osteosarcoma at the Site of a Cortical Bone Allograft in a Dog

An osteosarcoma developed in the proximal femur of a 9-year-old female Great Dane. The femur had been fractured 5 years previously and was stabilized with plate fixation with the incorporation of a frozen cortical bone allograft. The dog recovered without complications after the surgery and had normal use of the leg before the osteosarcoma developed. The tumor had metastasized to the lungs, spleen, and ipsilateral popliteal lymph node.