Low-field magnetic resonance changes in the paravertebral musculature of dogs with acute intervertebral disc extrusion.

OBJECTIVES: To describe the MRI features and prevalence of paravertebral muscle signal intensity changes in dogs with acute intervertebral disc extrusion and to search for associations between the signal changes and clinical history, signalment, neurological examination, serum creatine kinase activity and MRI characteristics of the disc herniation. MATERIALS AND METHODS: Medical records and MRI examinations from 688 dogs with surgically confirmed acute intervertebral disc extrusion were reviewed retrospectively. T2-weighted and STIR MRI sequences were available for 276 cases and were examined for paravertebral muscle signal intensity changes. When present, extension, lateralisation and signal characteristics of these changes were recorded. Exclusion criteria were muscle injections 24 hours before MRI scan, trauma and previous spinal surgery. RESULTS: Nineteen dogs met the inclusion criteria. There were signal changes in the multifidus muscle, mostly in the thoracolumbar region and often extending caudally from the level of the intervertebral disc herniation. Two cases had paravertebral muscle signal intensity changes in the cervical region. MRI signal changes were seen more frequently in the muscles of non-ambulatory dogs. Clinical history and neuro-examination did not allow differentiation between dogs with and without paravertebral muscle signal intensity changes. CLINICAL SIGNIFICANCE: Paravertebral muscle signal intensity changes were observed infrequently in the epaxial musculature of 6.9% dogs with acute intervertebral disc extrusion in both the thoracolumbar and cervical regions. The pathophysiological processes responsible for these MRI changes remain unknown.

Primary penile adenocarcinoma with concurrent hypercalcaemia of malignancy in a dog.

A 13-year-old male neutered Siberian husky crossbreed dog was presented with a 3-week history of haematuria and penile swelling. Clinical examination and computed tomography demonstrated a soft-tissue mass located at the base of the penis without signs of other primary tumours or metastasis. Clinicopathological findings revealed paraneoplastic hypercalcaemia. Fine-needle aspiration cytology of the mass suggested an epithelial tumour with several criteria of malignancy present. Following surgical excision of the mass, the hypercalcaemia resolved. Histopathology and immunohistochemistry revealed features consistent with an adenocarcinoma. Despite thorough examination, no perineal or anal sac tumour was found. To the authors' knowledge, this is the first reported case of a penile adenocarcinoma with hypercalcaemia of malignancy.

Diagnostic value of MRI in dogs with inflammatory nasal disease.

OBJECTIVES: To determine the value of low-field magnetic resonance imaging in differentiating sino-nasal aspergillosis from lymphoplasmacytic rhinitis in dogs. METHODS: A retrospective study of 41 dogs (25 with lymphoplasmacytic rhinitis and 16 with sino-nasal aspergillosis) that underwent magnetic resonance imaging scan of the nasal cavity was conducted. On magnetic resonance imaging, turbinate destruction was classified as mild, moderate or severe. The cribriform plate and vomer destruction were classified as present or absent. The intensity of fluid accumulation and turbinates was classified on T1-weighted and T2-weighted images as hypointense, hyperintense and isointense based on the brightest area on the same slice. RESULTS: Turbinate destruction was significantly (P=0·005) associated with sino-nasal aspergillosis. On T1-weighted images, sino-nasal aspergillosis was associated with turbinate hyperintensity, while lymphoplasmacytic rhinitis was significantly (P=0·007) associated with hypointensity. On T2-weighted images, this feature was shown not to be relevant. CLINICAL SIGNIFICANCE: This study has demonstrated that turbinate destruction is the most reliable feature to differentiate sino-nasal aspergillosis from lymphoplasmacytic rhinitis and that T1-weighted image was the most useful sequence.

Histopathology inflammation scoring and classification in 34 dogs with inflammatory nasal disease.

The aims of this study are to suggest a histological classification and a scoring system (0-12) for dogs with inflammatory nasal disease, and to compare and determine statistical associations between histopathology findings and lymphoplasmacytic rhinitis (LPR) or aspergillosis. Twenty-one LPR cases and 13 aspergillosis cases were reviewed and classified at the Queen's Veterinary School Hospital of the University of Cambridge. Statistical analysis was performed using SPSS V.17 and the level of significance accepted was P<0.05. The suggested classification includes the name of the two most common inflammatory cells found, duration of disease, lesion distribution, severity of epithelial and goblet cell hyperplasia and presence of oedema and fungi. The inflammation score was calculated according to the number of inflammatory cells present, and revealed that half the cases had moderate nasal inflammation and that most of the cases (67.6 per cent) were lymphocytic rhinitis. As far as the statistical associations were concerned, only fungal presence was proven to be associated with aspergillosis (P=0.04). The two conditions were found to have similar histological appearance. Implying that the histological diagnosis can sometimes be difficult and that the clinician should always consider the results from other diagnostic tests to reach a final diagnosis.