Mediastinectomy for management of chronic pyogranulomatous pleural disease in dogs.

The medical records of 12 dogs with chronic pyogranulomatous pleural disease unresponsive to medical management were reviewed retrospectively. Resection of the mediastinal pleura (mediastinectomy) was performed through a median sternotomy to remove all diseased and surgically accessible mediastinal pleural tissue. Dogs were re-examined two weeks postoperatively, and long-term outcome was evaluated by contacting owners by phone. Twelve dogs underwent mediastinectomy; additional surgeries included subtotal pericardiectomy (8), lung lobectomy (4) and partial diaphragmatic resection (2). Histology of resected tissue consistently revealed neutrophilic, pyogranulomatous cellulitis/serositis. Foreign material was evident in the mediastinal tissue of five dogs and microorganisms were recovered from three dogs. Two dogs developed pneumothorax immediately postoperatively; one dog developed haemothorax one month postoperatively and was euthanased. Median follow-up time was eight months (range: 6-43 months); eleven dogs were alive and considered to be symptom-free by their owners. Mediastinectomy resulted in complete resolution of symptoms in most dogs (92 per cent) and was associated with a low incidence of major complications. The results of this study indicated that mediastinectomy results in favourable outcome for dogs with chronic pleural pyogranulomatous pleural disease unresponsive to medical management.

Prognostic significance of specific magnetic resonance imaging features in canine nasal tumours treated by radiotherapy.

OBJECTIVES: To investigate the prognostic significance of the magnetic resonance (MR) findings of meningeal hyperintensity of the olfactory bulbs and tumour extension into the caudal nasal recess (CNR) in dogs with nasal tumours treated by radiotherapy. METHODS: MR images of 41 dogs with nasal tumours treated with radiotherapy were reviewed. The occurrence of neurological signs and survival of patients with and without meningeal hyperintensity of the olfactory bulbs and tumour extension into the CNR were analysed together with possible confounding factors including intracranial extension and patient age. RESULTS: There was no significant association between the presence of meningeal hyperintensity or CNR involvement and the occurrence of neurological signs. Although there was a tendency towards shorter survival in dogs with tumour extension into the CNR, multivariable analysis showed no significant difference in survival between dogs with/without CNR involvement, meningeal hyperintensity or intracranial tumour extension (P=0.12, 0.50 and 0.57, respectively). CLINICAL SIGNIFICANCE: In dogs with nasal tumours treated with radiotherapy, tumour extension into the cranium is not necessarily associated with shorter survival in patients without neurological signs at time of diagnosis. Although a definite influence of CNR involvement on case outcome could not be demonstrated, studies with a larger population are warranted.