Long term survival in two German shepherd dogs with Aspergillus-associated cavitary pulmonary lesions.

We read with interest the case report by Kulendra and others (2010). We note that the case described decompensated suddenly and was euthanized 13 months postoperatively, with some evidence for bacterial airway infection but without post-mortem examination to establish the reason for decompensation. We wish to draw the attention of interested readers to two cases of cavitary pulmonary lesions associated with Aspergillus sp. infection that we have seen that, not only have very striking similarities to the published report, but for which longer follow up is available, documenting survival for several years when removal of the affected lung lobe was followed with systemic antifungal therapy. Both cases were adult male neutered German shepherd dogs, presenting to referral institutions following several weeks of antibiotic therapy for a chronic cough that had progressed to haemoptysis. Notable clinical findings on haematology and biochemistry screens included moderate eosinophilia 4.5 x 10/L (reference range 0 to 1.25 x 10/L) in one dog and a mild increase in band neutrophils 0.46 x 10/L (reference range 0-0.3 x 10/L) with mild hyperphosphatemia 3.6 mmol/L (reference range 0.8 to 1.6 mmol/L) in the other. Thoracic radiographs showed a large cavitary lesion in the left cranial lung lobe, with diffuse alveolar densities in other areas of the left lung lobes in both dogs. Bronchoscopy showed blood arising from the bronchus supplying the left cranial lung lobe in both dogs with rivulets of blood in other tertiary bronchi throughout the thorax in one dog. Bronchoalveolar lavage (BAL) revealed a mixed inflammatory response dominated by neutrophils and macrophages. In one dog the macrophages showed erythrophagia and a solitary filamentous structure with pale borders was embedded within the mucus and neutrophils. Bacterial and fungal cultures of BAL fluid were negative in both dogs. Left cranial lobectomy and removal of the associated lymph node was performed in both dogs. Adhesions were present to the parietal pleura in one dog and mediastinum in the other. In both dogs the resected lung lobe was grossly discoloured and contained a large cavitated lesion. Histopathology showed that the lining of the cavity was composed of a thick layer of granulating and sometimes fibrous tissue covered with necrotic debris in which numerous fungal hyphae were present. Additional changes were local bronchiolitis obliterans, atelectasis and peribronchial inflammatory infiltrates. The local lymph nodes were reactive. In both dogs lung tissue yielded a heavy growth of Aspergillus sp. The species was determined to be Aspergillus fumigatus in one dog and not further classified in the other. The final diagnosis was cavitary pulmonary lesion associated with Aspergillus sp. infection in both dogs. Fungal culture of the urine was negative in one dog and not performed in the other. Postoperative recovery was unremarkable and both dogs received postoperative treatment with itraconazole (Sporanox; Janssen-Cilag Ltd.) at 5mg/kg orally once daily for 6 weeks in one dog and 5mg/kg twice daily for 4 weeks in the other. Follow up clinical and radiographic assessment at 4 weeks postoperatively showed no evidence of recurrence in either dog. One dog is still doing well 3 years postoperatively and the other dog died of unrelated causes 6 years postoperatively. These two additional cases may suggest that German shepherd dogs are predisposed not only to disseminated aspergillosis but also to this specific manifestation of localised Aspergillus infection, documented as Aspergillus fumigatus in two out of the three dogs. It is remarkable that all three dogs presented with haemoptysis and that the lesion appeared confined to the left cranial lung lobe in all dogs. The reason for acute decompensation at 13 months postoperatively in the case reported by Kulendra and others (2010) was not determined, but local recurrence or recrudescence of Aspergillus infection (as can happen after this time period in nasal aspergillosis) would certainly have to be considered as a differential. Therefore, potential for survival beyond this time in the absence of antifungal therapy is unknown. However, based on the long term follow-up in the two dogs we have seen, surgical removal of affected tissue followed by at least 4 weeks of itraconazole therapy has potential to be curative.