Interthalamic adhesion thickness has been previously described as a parameter for quantifying canine brain atrophy and hypothesized to correlate with brain height or ventricular size. However, studies testing this hypothesis are lacking. This retrospective cross-sectional study aimed to compare interthalamic adhesion thickness, interthalamic adhesion thickness/brain height ratio, and interthalamic adhesion thickness/brain height ratio/lateral ventricle to brain height ratio values in dogs with and without cognitive dysfunction. Medical records for dogs meeting the following inclusion criteria were retrieved from two hospitals: available brain magnetic resonance imaging (MRI) or computed tomography (CT) studies, no cerebral parenchymal lesions, and no prior neurological treatment. For each included dog, values of interthalamic adhesion thickness, interthalamic adhesion thickness/brain height ratio, and interthalamic adhesion thickness/brain height ratio/lateral ventricle to brain height ratio were measured by one observer from transverse CT or MRI images and a consensus was reached. A total of 113 dogs met inclusion criteria. Dogs were divided into three groups based on the following criteria: Young group (no cognitive dysfunction, <9-year-old, n = 43), Aging group (no cognitive dysfunction, ≥9-year-old, n = 61), and Dementia group (n = 9). All three parameters were significantly lower in the dementia group than in the Young and Aging groups. In the Young and Aging groups, there was significant negative correlation of all three parameters with age and positive correlation of interthalamic adhesion thickness and interthalamic adhesion thickness/brain height ratio/lateral ventricle to brain height ratio with body weight, while there was no correlation of interthalamic adhesion thickness/brain height ratio with body weight (P < 0.05). There were no differences in all three parameters according to skull type or gender. Findings from the current study supported the use of interthalamic adhesion thickness, interthalamic adhesion thickness/brain height ratio, and interthalamic adhesion thickness/brain height ratio/lateral ventricle to brain height ratio for quantifying brain atrophy in dogs with cognitive dysfunction.

The purpose of this study was to determine the relationships among body condition score (BCS), radiography, and computed tomography (CT), and to establish a method for body fat assessment on CT in dogs. Thirty eight Beagles with 2 to 7 BCS were examined. Subcutaneous fat thickness (ST) on radiograph and body area (BA), total fat area (TA), subcutaneous fat area (SA), and visceral fat area (VA) on CT were measured at the level of L3 and L6 vertebra. Ratios of each value to the L6 length were obtained (rST, rTA, rSA, rVA) and the correlations with BCS were estimated. The value of VA/SA, VA/TA, TA/BA, VA/BA, and SA/BA were selected for measuring fat and the correlations with BCS were estimated. The rST, rTA, rSA, and rVA were significantly correlated with BCS, and the rTA and rSA were significantly correlated with rST. At the level of L3, rTA and rVA had stronger relationships with BCS than at L6 while rSA had a higher correlation with BCS at L6. The TA/BA, VA/BA, and SA/BA were significantly correlated with BCS, and the upper limits were 15.11, 6.31, and 8.92%, respectively. Our results showed that CT could be useful to assess body fat and TA/BA, VA/BA, and SA/BA are suitable criteria for measuring fat on CT. In addition, L3 was a more suitable location for evaluating total and visceral fat, and L6 was more suitable for evaluating subcutaneous fat.

This study describes magnetic resonance imaging (MRI) results and changes in lateral ventricular size over time in a canine ischemic stroke model. T1- and T2-weighted (T1W, T2W) imaging and fluid-attenuated inversion recovery (FLAIR) sequence MRI were performed at 3 h and 3, 8, and 35 days after brain infarct induction. Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping were performed at 8 and 35 days. A total of 29 brain lesions were induced successfully in 12 of 14 beagle dogs. At 3 h, T2W and FLAIR detected hyperintense lesions in three randomly selected dogs. On T1W, all lesions appeared hypointense to isointense at 3 h, isointense (18/29) or hypointense (11/29) at 3 days, hypointense to isointense with peripheral hyperintensity (24/26) at 8 days, and hypointense (18/26) at 35 days. Infarcts on DWI/ADC were hypointense to isointense centrally, with the periphery hyperintense/hyperintense (17/26) at 8 days and hypointense/hyperintense (19/26) at 35 days. A marked increase in lateral ventricular size was observed in dogs with cerebral infarcts. In conclusion, T2W and FLAIR were useful for detecting early stage (3 h to 3 days) brain infarction. T1W and DWI were useful for detecting neuronal necrosis and providing supplemental information for phase evaluation.

Susceptibility-weighted imaging (SWI) is a magnetic resonance imaging (MRI) sequence used for evaluating traumatic brain injury (TBI). Although SWI is being increasingly used in veterinary medicine, there are no systematic studies regarding its use. We aimed to evaluate TBI lesions by using conventional MRI and SWI in 11 dogs and determine the correlation between clinical status and conventional MRI or SWI findings. The modified Glasgow coma scale (MGCS) at presentation and a previously used MRI grading system (MRGr; grades 1–6) were used to evaluate the brain lesions, and correlations between MGCS score and each MRGr were assessed. Conventional MRI revealed 23 lesions in 11 dogs with variable MGCS scores (range: 11–17). SWI showed comparable findings for all of the lesions except for subdural hemorrhage, and it revealed additional lesions in four dogs. The median MRGr was 2 on both conventional MRI and SWI. The MRGr of the conventional MRI assessments and the MGCS scores showed a significant negative correlation ( r = −0.685). In conclusion, SWI had better TBI lesion-detection ability, but conventional MRI had a better correlation with early clinical status and subdural hemorrhage. Thus, a combination of conventional MRI and SWI examinations can improve TBI diagnosis in dogs.

Pharyngeal collapsibility has been used as diagnostic criteria in dogs, whereas the normal range and quantitative method have not been studied. Dynamic and static computed tomography (CT) was performed in 23 normal Beagle dogs to quantify the nasopharyngeal collapsibility at different locations. Using dynamic CT, maximum and minimum nasopharyngeal cross-sectional areas (CSAs) were measured at the level of the cranial end of the soft palate, pterygoid hamulus, foramen lacerum, bony labyrinth, and caudal end of the soft palate. The ratio of all maximum and minimum CSA to nasopharyngeal CSA at the level of the caudal hard palate (rCSAmax and rCSAmin) and the nasopharyngeal collapsibility were calculated. The differences of rCSAmax, rCSAmin, and nasopharyngeal collapsibility were analyzed at various locations. The nasopharyngeal collapsibility at the level of foramen lacerum, bony labyrinth, and caudal end of soft palate were higher than the others. At the level of the caudal end of the soft palate, rCSAmin was lower than that of the foramen lacerum and bony labyrinth, whereas rCSAmax at foramen lacerum was higher than that of the caudal end of the soft palate. These results indicated that the nasopharynx at the level of foramen lacerum and caudal end of the soft palate were considered notable locations for evaluating collapsibility. Dynamic CT could show the nasopharyngeal dynamic profile and will be an adequate modality for evaluating nasopharynx. Our results will be helpful for further comparative studies in dogs with and without nasopharyngeal collapse.

A normal spleen is a homogeneous, finely textured, and hyperechoic organ. The development of high‐frequency transducers has enabled the examination of the structural features of the spleen. Thus, the spleen can appear mildly mottled, even in normal dogs, and this could be misinterpreted as an abnormality. The purpose of this prospective, longitudinal, descriptive study was to describe the ultrasonographic pattern of the splenic parenchyma using a high‐frequency transducer in puppies. The study included nine, normal, client‐owned puppies that were born healthy. Transabdominal ultrasonographic examination was performed from 4 to 60 weeks serially every 4 weeks. Ultrasonographic patterns of the spleen were graded as follows: granular, mild reticulonodular, moderate reticulonodular, and marked reticulonodular pattern. The examinations were performed by one veterinary clinician, and the grades of the ultrasonographic patterns were determined by two veterinary clinicians experienced in ultrasonography, based on consensus. Differences and associations between time and the grade of the splenic parenchyma were determined using the paired t‐test and scatter plots. There was a strong quadratic relationship between time and the grade of the splenic parenchyma. It was found that the splenic parenchymal patterns changed with increasing age, with a granular appearance initially at 4 weeks, followed by a reticulonodular pattern with well‐defined hypoechoic nodules—most marked between 28 and 36 weeks, after which this pattern decreased until there was a homogeneous granular pattern again at 60 weeks. These findings should not be misinterpreted as being indicative of a disease in normal puppies, particularly those aged between 28 and 36 weeks.

Liposarcoma of the spermatic cord is extremely rare in dogs and humans. This report describes the clinical signs, typical diagnostic imaging including ultrasound and computed tomography, and treatment of a liposarcoma of the spermatic cord of a Toy Poodle confirmed by histological examination after a surgical procedure. This case highlights the importance of preoperative diagnostic imaging and histopathological examination in dogs with an inguinal or scrotal mass.

Background: Most extramedullary plasmacytomas (EMPs) aresolitary and located in the head and neck region. They may also occur in the visceral parts of the body.Objectives: Here, we report a case of oral EMP followed by neoplastic plasma cell metastasis to both kidneys in a neutered male Pomeranian. Methods: Oral plasmacytoma recurred 11 months aftersurgical removal of an oral mass and partial maxillectomy was performed. Eighteen months after partial maxillectomy, neoplastic masses were detected in both kidneys on computed tomography.The dog died 12 months after detection of bilateral kidney neoplasms. The resected neoplastic masses were routinely processed for histopathological observation and immunohistochemistry against pan-cytokeratin, desmin, CD3, and MUM-1. Results:The recurred mass mainly consisted of well-differentiated plasma cells and contained a small portion of aggressive cells with malignant features. Monoclonal gammopathy was not observed on serumelectrophoresis performed to exclude multiple myeloma. The mass was composed of plasma cells with high nuclear pleomorphism and abundant mitotic figures. The neoplasm stained positive for MUM-1 with a more aggressive morphology than in oral EMP. Conclusion:Based on serum biomarker and pathological observations, a diagnosis of recurrence and metastasis of oral-to-renal EMP was established. To the best of our knowledge, metastasis of oral EMP into the bilateral kidneys, as described in the current case, has not been previously reported in dogs.