A simplified CT-volumetry method for the canine liver.

Computed tomographic (CT) liver volumetry using the slice addition technique is an accurate, but a time-consuming method. Commonly used DICOM-viewing software only allows contouring of one area per image, which can be troublesome in the transverse plane as different lobes are separated. In this prospective, experimental, methods comparison study, we aimed to determine if hepatic contouring using sagittal reformatting and a reduced number of images would yield accurate results. Computed tomographic studies were performed in five canine cadavers and reviewed using sagittal reformatting. For each dog, the number of images that included the liver was used to create four stacks with progressively fewer images in which the liver would be contoured, each with the following median number of images: A: 60, B: 31, C: 16, and D: 9. Liver volume was calculated by three observers using the different stacks of images. After CT examination, the cadavers were dissected, the liver was removed, and its volume was determined by water displacement. Single score intraclass correlation coefficient was calculated to assess interobserver agreement. Kruskal-Wallis test was used to compare water displacement and CT-based volumes. There was excellent agreement between observers (intraclass correlation coefficient = 0.957; 95% confidence interval, 0.908-0.982, P < 0.0001). No significant difference was found between the volumes obtained by CT-volumetry using each of the stacks and the volumes obtained by water displacement. Using sagittally reformatted images and hepatic contouring in as few as nine images can be an accurate and simple method for CT-volumetry of the canine liver.

Vascular ultrasonographic findings in canine patients with clinically diagnosed phlebitis.

Peripheral vein phlebitis (inflammation) is a relatively frequent complication in dogs, however, published information on the ultrasonographic characteristics is currently lacking. This prospective, observational study describes the ultrasound (US) characteristics of normal canine cephalic veins, and veins with clinical phlebitis. Correlations among US findings and between US findings versus time that the intravenous catheter was in place were investigated. Safety of the US procedure was evaluated. Fifty patients were prospectively recruited for the study and 18 met the final inclusion criteria. Each patient underwent daily US examinations and was assessed for multiple criteria (vascular wall appearance, compressibility, spontaneity of flow, color fill, and presence/absence of filling defects, flow contour, direction, non-pulsatility). Characteristics of normal canine cephalic veins were as follows: smooth and thin wall, complete compressibility, no flow disturbances, no filling defects, smooth flow contours, and unidirectional, non-pulsatile flow with no turbulence. Characteristics of cephalic veins with clinical phlebitis were as follows: wall thickening (83%), decreased compressibility (55%), filling defects consistent with intraluminal thrombus (55%), vessel wall hyperechogenicity (44%), and abnormal color Doppler flow (39%). Significant correlations were found between Doppler filling defects and compressibility, Doppler filling defects and presumed thrombosis, and compressibility and presumed thrombosis (P = .001, P = .001, P = .000, respectively). No correlation was found between the US findings and time the intravenous catheter was in place. Findings indicated that duplex and compressibility US are feasible and safe methods for characterizing and monitoring cephalic veins in dogs with clinical phlebitis.

What Is Your Diagnosis?

In collaboration with the American College of Veterinary Radiology.

MRI of the optic nerve sheath and globe in cats with and without presumed intracranial hypertension.

OBJECTIVES: The study aimed to: (1) test MRI repeatability of measurements of optic nerve sheath diameter (ONSD), optic nerve diameter (OND) and eye globe transverse diameter (ETD); (2) investigate the associations between the OND, ONSD and ETD; (3) assess whether these measurements are affected by age or body weight; and (4) test the association between ONSD, OND, ETD and ONSD:ETD ratio with presumed intracranial pressure (ICP) status. METHODS: This was a retrospective and blinded study where patients were allocated to presumed normal or intracranial hypertension groups based on MRI findings. The ONSD and ETD were measured and recorded. Interclass correlation coefficient (ICC) was calculated to investigate interobserver agreement. Data were analysed using the Pearson correlation coefficient, two-sample t-test and general linear model ANOVA. RESULTS: Seventy-seven cats were included, 62 with presumed normal ICP and 15 with presumed intracranial hypertension. The ICC showed moderate-to-good reliability for all measurements. Positive correlations were identified for: (1) ETD and weight; (2) ONSD and age; (3) OND and age; (4) ONSD and ETD; (5) ONSD:ETD ratio and presumed ICP status; and (6) ONSD and presumed ICP status. No difference was detected between the presumed normal and intracranial hypertension groups and ONSD, as well as ONSD:ETD ratio and presumed ICP status when patient age was considered. CONCLUSIONS AND RELEVANCE: The measurement of the ONSD and the ONSD:ETD ratio on T2-weighted MRI might not be reliable as non-invasive tests for diagnosing intracranial hypertension in cats.

Systemic Mycobacterium kansasii Infection in Two Related Cats.

Mycobacterial infections are a major concern in veterinary medicine because of the difficulty achieving an etiological diagnosis, the challenges and concerns of treatment, and the potential zoonotic risk. Mycobacterium kansasii, a slow-growing non-tuberculous mycobacteria, causes disease in both humans and animals. While infections have been well described in humans, where it may be misdiagnosed as tuberculosis, there are fewer reports in animals. Only four cases have been reported in the domestic cat. This case report describes systemic M. kansasii infection in two sibling indoor-only cats that presented two and half years apart with cutaneous disease that was found to be associated with osteolytic and pulmonary pathology. Infection with M. kansasii was confirmed in both cats by polymerase chain reaction on fine-needle aspirate of a lumbosacral soft tissue mass in one cat and on a tissue punch biopsy of a skin lesion in the other; interferon-gamma release assay inferred M. avium-complex and M. tuberculosis-complex infection in the two cats, respectively. Both patients made a full recovery following antimicrobial therapy with rifampicin, azithromycin, and pradofloxacin (plus N-acetyl cysteine in cat 2). This report highlights successful treatment of systemic M. kansasii mycobacteriosis in the cat and the challenge of accurately diagnosing this infection.

Lymphoma with Mott cell differentiation and validation of immunohistochemical lymphoid markers in an African pygmy hedgehog (Atelerix albiventris).

A 2-year-old female intact African pygmy hedgehog was presented for diagnostic investigation of a 2-month reduction in appetite, with weight loss and recent vomiting. Clinical examination revealed a large, firm mass originating from the left cranial abdomen. Ultrasound-guided fine-needle aspirates of the mass, liver, and mesenteric lymph nodes revealed a population of pleomorphic round cells, some of which contained variable numbers of round, clear vacuoles, consistent with a diagnosis of lymphoma with Mott cell differentiation. At postmortem examination, there was marked diffuse splenic enlargement, with infiltration by a soft tissue mass. There were multiple coalescing liver masses, kidney pallor, and mesenteric lymph node enlargements. On histologic examination, the spleen, lymph nodes, and masses in the liver were extensively infiltrated by proliferating lymphoid cells that had plasmacytoid and Mott cell differentiation. Cells with Mott cell morphology had an accumulation of periodic acid-Schiff-positive material in cytoplasmic inclusions and were positive for cytoplasmic nucleic acids when stained with methyl green pyronin. In the population of neoplastic lymphoid cells, a majority of cells expressed the transcription factor Pax5, which drives B-cell differentiation, and a minority expressed transcription factor IRF4/MUM-1, which drives plasma cell differentiation, indicating B-cell lymphoma with plasmacytoid differentiation.

Morphological variation of the caudal fossa of domestic cat skulls assessed with CT and geometric morphometrics analysis.

Objectives This study aimed to investigate differences and demonstrate a normal range of morphological variation of the caudal fossa of the cranium of domestic cats. Methods CT scans of 32 domestic cat heads of 11 breeds were included. Isosurfaces from skulls were characterised through three-dimensional geometric morphometrics using geographical landmarks placed on the internal surface of the caudal fossa and foramen magnum. Raw data was transformed with a Procrustes fit and coordinate covariance was analysed by principal components to establish breed- and sex-level differences. Skulls were also classified according to the number of concavities along the mid-sagittal vermiform impression. Differences were investigated between breed groups and sex, and correlation was sought with age. Results Analyses revealed size-independent differences in occipital bone morphology across breeds and sex; however, no clustering was evident. Most variability was observed at the exoccipital bones, ventral portion of the supraoccipital bone, dorsum sellae of the basisphenoid and the osseous tentorium cerebelli. No statistically significant differences were identified via two-sample t-tests between breed groups or sexes. No statistically significant correlation using Spearman rho correlation coefficient was identified with age. Conclusions and relevance The feline caudal fossa displays a wide range of intra- and inter-breed variation, not linked to age or sex. Concavities along the vermiform impression have not previously been described. As advanced imaging modalities are becoming more frequently used for domestic felids, an established range of normality is important for discriminating pathological changes from anatomical variances.

Systemic Rasamsonia piperina infection in a German shepherd cross dog.

Introduction. Infection with the Rasamsonia argillacea species complex represents an emerging problem in human and veterinary medicine with systemic mycoses presenting with significant clinical complications and being a cause of death. Case presentation. In this report, a case of systemic Rasamsonia piperina infection discovered in a 3-year-old male neutered, German shepherd cross dog is described together with the clinical presentation, the course of the disease and diagnosis. This report describes the first case of veterinary mycosis due to R. piperina in Europe and the first case in humans or animals in the UK. Conclusion. Although seemingly rare, R. argillacea species complex infection should be a differential diagnosis for dogs, especially German shepherds with the described presenting signs, and radiographic and ultrasonographic findings.