Bacterial liver parenchymal infections in dogs are rarely documented, and their imaging characteristics are scarce in the veterinary literature, especially in Computed Tomography (CT). This retrospective multicentric study aimed to describe the CT characteristics of parenchymal bacterial liver infection and abscessation in dogs and compare them with the human literature. Twenty dogs met the inclusion criteria. All dogs, except one, showed discrete hepatic lesions consistent with pyogenic liver abscess (19/20). A single case showed diffuse liver changes, which was diagnosed with granulomatous bacterial hepatitis (1/20). Multifocal lesions were associated with the presence of abdominal pain (p = 0.023). CT characteristics of pyogenic liver abscesses in our study resemble those described in the human literature, with multifocal (14/19) or single (5/19), round or ovoid (19/19), hypoattenuating hepatic lesions, which are better visualised in post-contrast images. Pyogenic liver abscesses can also show features such as the “cluster sign” (8/19), transient arterial segmental enhancement (6/10), rim enhancement (6/19), and intralesional gas (4/19). Additional CT findings, such as local lymphadenomegaly (18/20), peritoneal fat stranding (14/20), and peritoneal fluid (13/20), are also commonly observed.

Otitis externa (OE) is a common condition in dogs. Otoscopic examination is the standard diagnostic procedure, but not all external ear canal structures can be assessed otoscopically. Computed tomography (CT) has become a gold standard in the assessment of middle ear disease. This study aimed to assess the validity of CT for canine OE and to compare CT‐specific and otoscopy‐specific findings that are consistent with OE. CT studies of dogs referred for suspected OE were blindly reviewed by three observers for ear canal wall mineralization, thickness, and contrast enhancement. Otoscopic findings were used as the reference standard. The sensitivity and specificity of CT for the diagnosis of OE were 98.2% (95% confidence interval [CI]: 90.4%–99.7%) and 60.0% (95% CI: 10.7%–76.6%), respectively. The positive predictive value (PPV) was 84.4%, and there was substantial agreement (weighted κ = 0.65) between CT and otoscopic diagnosis of OE. There was moderate agreement (weighted κ = 0.47) between the presence of CT ear canal wall contrast enhancement and the degree of erythema otoscopically, and moderate agreement (weighted κ = 0.58), comparing the consensus CT grade for ear canal wall thickness to the grade of ear canal stenosis on otoscopic examination. The presence of external ear canal wall mineralization on CT was independent of disease ( p = 0.49) and disease duration ( p = 0.26), indicating mineralization of the external ear canal wall on CT is not necessarily related to chronic OE. There is substantial agreement between CT and otoscopy, supporting its use as a diagnostic technique for OE.

Mast cell tumors (MTCs) are a common splenic neoplasia in cats, although their ultrasonographic characteristics have been reported to be nonspecific and overlap with those of other proliferative diseases. The objective of this study was to describe ultrasonographic findings of the spleen and metastatic sites in a large cohort of cats with cytologically or histopathologically confirmed primary or disseminated splenic involvement by MCTs with high-frequency transducers, and to determine whether specific ultrasonographic characteristics could be identified. Cats with available ultrasonographic images and cytological or histological confirmation of splenic involvement by MCTs were retrospectively included in a multicenter study. Forty-one cats met the inclusion criteria. A linear transducer was used for the majority of cats (80%). Splenic abnormalities were identified in 85% of cats. The most common finding was diffuse splenomegaly (63%) with irregular margins (46%) and homogeneously hypoechoic parenchyma (24%). Specific patterns were uncommon, with a reticulonodular pattern present in 27% and a marbled appearance in 12% of cats. Discrete nodular lesions or masses were present in 44%. The liver was sampled in 66% of cats, and hepatic disseminated disease was confirmed in 59%; however, the liver was ultrasonographically normal in the majority of those cases. For the cats with hepatic MCTs and ultrasonographic abnormalities, diffuse hepatomegaly with abnormal echogenicity or echotexture was observed. Lymph node metastasis was confirmed in 20% of cats. Only one cat had confirmed gastrointestinal involvement by MCTs, and gastrointestinal ulceration was ultrasonographically noted in 7% of cats. In conclusion, to the authors’ knowledge, this is the largest study describing findings in splenic MCTs in which images were acquired predominantly using a high-frequency linear transducer. Nonspecific ultrasonographic splenic changes were associated with this disease. A normal ultrasonographic spleen or liver did not exclude mast cell tumor (MCT) involvement. Cytology or histopathology remains warranted when an MCT is suspected, particularly in the presence of splenomegaly in combination with suspicion of disseminated disease and a cutaneous MCT. Lymph node metastasis, gastrointestinal involvement by MCTs, and gastrointestinal ulceration were uncommon findings.