Background: Portal vein thrombosis (PVT) has been reported infrequently in dogs. Objectives: To characterize the presentation, associated disease conditions, and outcome in dogs with PVT. Animals: Client-owned dogs with a diagnosis of PVT and a complete medical record. Methods: Records were retrospectively analyzed for presentation, history, physical examination, clinicopathologic data, diagnostic imaging, treatment, and outcome.Results: Thirty-three dogs were included. Common clinical signs were vomiting, diarrhea, abdominal pain, ascites, and signs of hypovolemic shock. Associated disease conditions included hepatic (14/33), neoplastic (7/33), immune (5/33), and infectious (4/33) diseases, protein-losing nephropathy (3/33), hyperadrenocorticism (2/33), protein-losing enteropathy (1/33), and pancreatitis (1/33). Fourteen dogs were receiving glucocorticoids at the time of diagnosis. Twenty-nine dogs had at least 1 predisposing condition for venous thrombosis, and 11 had 2 or more. Thrombocytopenia (24/33), increased liver enzyme activity (23/33), and hypoalbuminemia (20/33) were common laboratory abnormalities. Clinical syndromes at the time of PVT diagnosis included shock (16/33), systemic inflammatory response syndrome (SIRS), (13/33) and disseminated intravascular coagulation (3/33). Twenty-four dogs had acute and 9 had chronic PVT. Multiple thrombi were found in 17/33 dogs. Nineteen dogs survived to discharge. Dogs treated with anticoagulant therapy were more likely, whereas those with acute PVT, multiple thromboses or SIRS were less likely to survive.Conclusions and Clinical Importance: Hepatic disease is a common pre-existing condition in dogs with PVT. PVT should be considered in dogs with risk factors for venous thrombosis presenting with abdominal pain, ascites, and thrombocytopenia. Studies evaluating anticoagulant therapy in the management of PVT are warranted.

This study compares clinical, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and pathology findings in 16 prospectively, and seven retrospectively recruited dogs presented for suspected thyroid carcinoma. Of these, 17 were confirmed thyroid carcinoma, while six were initially misdiagnosed. These included four carotid body tumors, one para-esophageal abscess, and one undifferentiated squamous cell carcinoma. Thyroid carcinomas occurred in older dogs without evidence of sex predilection, and were more often unilateral. All were large, heterogeneous, moderately to strongly vascularized, and most commonly contained areas of dystrophic mineralization and/or fluid accumulations. On MRI, thyroid carcinomas appeared hyperintense compared to surrounding musculature in all imaging sequences used, while on CT they had a lower attenuation value than normal thyroid gland tissue. Histologically confirmed tumor capsule disruption with invasion of the surrounding structures was most commonly detected with MRI. Palpation was not an accurate predictor of locally invasive vs. well-encapsulated masses. Computed tomography had the highest specificity (100%) and MRI had the highest sensitivity (93%) in diagnosing thyroid carcinoma, while ultrasound had considerably lower results. We conclude that ultrasound is adequate for use as a screening tool for dogs with suspected thyroid carcinoma, but recommend either CT or MRI for preoperative diagnosis and staging. C 2012 Veterinary Radiology & Ultrasound.

A 14-year-old Quarter Horse had chronic facial swelling and a more recent history of progressive bilateral epiphora. Radiographic findings were compatible with exostosis of the nasofrontal suture. Computed tomography (CT) of the head, including CT dacryorhinocystography, confirmed the diagnosis and allowed presurgical planning of resection of the exostosis, which resulted in resolution of the clinical signs.

Summary This retrospective study describes the computed tomography (CT) findings in 59 horses presented with diseases of the head over 8 years that underwent CT examination of this region, including dental or sinonasal diseases (Group A) (n = 42), osseous and/or articular diseases (Group B) (n = 11) and soft tissue diseases (Group C) (n = 6). For Group A, radiographic and CT findings comparison was possible. Computed tomography had higher sensitivity (100%) and specificity (96.7%) than radiography in diagnosing dental disease. Compared to CT, radiographic identification of sinus involvement was less sensitive, particularly for ventral conchal and sphenopalatine sinuses and presented an overall sensitivity of 43.5 and 16.7%, respectively. In Group B CT allowed identification of a higher number of bone fragments and fractures in the maxillary, lacrimal, sphenoidal, temporal and zygomatic bones not identified radiographically. Accurate identification of CT changes in the temporomandibular joint and temporohyoid articulation was also possible. Group C included both intra‐ and extra‐cranial disease, retrobulbar masses being the most representative pathology (n = 3). In this group, CT was considered the gold standard for detection of periorbital diseases. We conclude that CT is an imaging technique with high diagnostic value for evaluating the equine head, yielding additional information over multiple radiographic views, which may alter the outcome of the case. Additionally, this paper reports several conditions not previously described using CT.

The equine head is an anatomically complex area, therefore advanced tomographic imaging techniques, such as computed tomography or magnetic resonance imaging (MRI), are often required for diagnosis and treatment planning. The purpose of this multicenter retrospective study was to describe MRI characteristics for a large sample of horses with head disorders. Horses imaged over a period of 13 years were recruited. Eighty-four horses met the inclusion criteria, having neurological (n = 65), sinonasal (n = 14), and soft tissue (n = 5) disorders. Magnetic resonance imaging accurately depicted the anatomy and allowed identification of the primary lesion and associated changes. There were good correlations between MRI findings and intraoperative or postmortem results. Magnetic resonance imaging showed the exact localization of the lesions, their size, and relation to surrounding structures. However, in the neurological group, there were 45 horses with no MRI abnormalities, 29 of which had a history of recurrent seizures, related to cryptogenic epilepsy. Magnetic resonance imaging was otherwise a valuable diagnostic tool, and can be used for studying a broad range of head disorders using either low-field or high-field magnets.

The computed tomographic (CT) features of the normal thyroid gland were compiled from images acquired in 25 client-owned dogs without thyroid gland disease. The mean pre- and postcontrast attenuation values were 107.5 and 169.0 Hounsfield Units, respectively. After injection of intravenous contrast medium (600 mg iodine/kg), the apparent thyroid gland volume (both lobes combined) increased from a mean value of 1148.0 nm3 to a mean value of 1188.9 mm3. All thyroid lobes were homogeneous on pre- and postcontrast images. In a craniocaudal direction, the gland spanned a region from the 1st to the 8th tracheal ring and the right lobe was often more cranial than the left. On transverse images the lobe shape was ovoid in 72%, and its location was dorsolateral to the trachea in 90% of dogs. Parathyroid glands could not be identified and an isthmus connecting both thyroid lobes was only seen in one dog. Considering the excellent visibility of the normal canine thyroid gland, CT can be beneficial in the differentiation of thyroidal versus nonthyroidal neck masses. CT also yields potential in the staging of thyroid carcinomas.

Results indicated that CEUS was safe in dogs and cats.

To describe the contrast-enhanced ultrasonographic appearance of various focal, space-occupying renal lesions and determine its value in their detection and characterization. Following baseline B-mode sonography of 15 dogs and one cat with renal space-occupying lesion(s), contrast-enhanced sonography was performed. The resulting images were evaluated qualitatively using conspicuity and number of lesions, and enhancement patterns were assessed during early arterial and late corticomedullary phases. Renal lesions were malignant in the cat (renal cell carcinoma) and 10 dogs (four renal cell carcinoma, two histiocytic sarcoma, one B-cell lymphoma, two hemangiosarcoma metastasis, one ch emodectoma metastasis) and benign in five dogs (two abscesses, one traumatic hematoma, one idiopathic hematoma, one hemorrhagic/necrotic nodule). Substantial overlap was present regarding the baseline sonographic features of benign vs. malignant lesions. With contrast-enhanced sonography, all renal cell carcinomas were characterized by large tortuous arteries, sometimes enhancing slightly earlier than vessels in the surrounding normal kidney. During the late corticomedullary phase, renal cell carcinomas had intense homo- or heterogeneous, iso- or slightly hypoechoic enhancement, which decreased progressively. Compared with renal cell carcinoma, histiocytic sarcoma and lymphoma had smaller and less obvious arteries, and an earlier loss of enhancement during the late phase. All hemangiosarcoma metastases appeared as nonenhancing nodules during the early arterial and late corticomedullary phases of enhancement, and additional lesions were detected. Histiocytic sarcoma and benign lesions had increased conspicuity with baseline sonography. The descriptions provided herein will be valuable as more work is done to establish the role of contrast-enhanced sonography in the assessment of renal lesions.