Congenital Portosystemic Shunts in Dogs and Cats: Treatment, Complications and Prognosis.

Congenital portosystemic shunts (CPSS) are a common vascular anomaly of the liver in dogs and cats. Clinical signs of CPSS are non-specific and may wax and wane, while laboratory findings can raise the clinical suspicion for CPSS, but they are also not specific. Definitive diagnosis will be established by evaluation of liver function tests and diagnostic imaging. The aim of this article is to review the management, both medical and surgical, complications, and prognosis of CPSS in dogs and cats. Attenuation of the CPSS is the treatment of choice and may be performed by open surgical intervention using ameroid ring constrictors, thin film banding, and partial or complete suture ligation or by percutaneous transvenous coil embolization. There is no strong evidence to recommend one surgical technique over another. Medical treatment strategies include administration of non-absorbable disaccharides (i.e., lactulose), antibiotics, and dietary changes, and are indicated for pre-surgical stabilization or when surgical intervention is not feasible. After CPSS attenuation, short- and long-term post-surgical complications may be seen, such as post-operative seizures and recurrence of clinical signs, respectively. Prognosis after surgical attenuation of CPSS is generally favorable for dogs and fair for cats.

Congenital Portosystemic Shunts in Dogs and Cats: Classification, Pathophysiology, Clinical Presentation and Diagnosis.

Congenital portosystemic shunts (CPSS) are abnormal vascular communications between the portal and the systemic circulation, bypassing the hepatic parenchyma and resulting in liver hypoplasia and hepatic insufficiency. Such connections develop in utero and persist postnatally. CPSS are among the two most common congenital vascular anomalies of the liver in small animals, along with primary hypoplasia of the portal vein without portal hypertension (PHPV without PH). CPSS can be extrahepatic (ECPSS), most commonly diagnosed in small and toy breed dogs and cats, or intrahepatic (ICPSS), most commonly seen in large breed dogs. Single ECPSS is the most common type encountered in both dogs and cats. Clinical signs of CPSS are non-specific and may wax and wane, while laboratory findings can raise clinical suspicion for CPSS, but they are also not specific. Definitive diagnosis will be established by evaluation of liver function tests, such as determination of fasting plasma ammonia (FA) levels, and pre- and postprandial serum bile acids concentrations, and diagnostic imaging. The purpose of this article is to review the definition, classification, pathogenesis, clinical presentation, and diagnosis of CPSS in dogs and cats, highlighted by the authors' clinical experience.

Contrast enhanced computed tomography assessment of superficial inguinal lymph node metastasis in canine mammary gland tumors.

Mammary gland neoplasms are predominant in dogs. However, sentinel lymph node (SLN) status assessment criteria have not been established for these cases. In this retrospective, secondary analysis, diagnostic case control study, CT images of 65 superficial inguinal SLNs were obtained before and 1, 3, 5, and 10 min after intravenous administration of contrast agent (iopamidol 370 mgI/mL). The presence and degree of postcontrast enhancement were assessed, by means of the median absolute density value and the maximum absolute density value at any time point in the center and in the periphery of each SLN measured in Hounsfield units (HU), before and after contrast agent administration. These values were compared with histopathological findings postsurgical excision. Receiver operating characteristic analysis was conducted. The absolute density values ranged widely at each time point and within each group of nodes (negative, positive, control group). At all time points, the median density value in the center and in the periphery was significantly higher in metastatic than in non-metastatic SLNs (P ≤ .014). Among the parameters tested, the median absolute density value measured in the periphery of the SLN 3 min after injection showed the highest sensitivity, specificity, and accuracy (AUC) (87.5%, 82.1%, and 92.1% respectively), with a cutoff value of 50.9 HU. The maximum absolute density value at any time point in the center and periphery of the SLNs was also significantly higher in metastatic SLNs compared to non-metastatic (P ≤ .001). With a cutoff value of 59.5 HU, the maximum absolute density value in the periphery of the SLN displayed high sensitivity and specificity (87.5% and 89.3%, respectively). The results of this study support the hypothesis that contrast enhanced CT imaging may aid in the assessment of SLN metastasis in dogs with mammary gland neoplasms.

Bilothorax Associated with Bile Peritonitis in a Dog with No Diaphragmatic Disruption: A Case Report.

A 4-year-old intact male mixed-breed dog was presented with vomiting and severe depression of 6-day duration after being struck by a car 2 weeks before presentation. Clinical examination revealed hypothermia, respiratory difficulty, jaundice, and a bicavitary (pleural and peritoneal) effusion. Hematological and biochemical abnormalities included neutrophilic leukocytosis, increased total bilirubin concentration, and increased serum lipase activity. Biochemical and cytological evaluation of both abdominal and thoracic fluids were suggestive of bilious effusions. During celiotomy, a rupture of the cystic duct was observed, which necessitated cholecystectomy. A diaphragmatic rupture was not found. A thoracostomy tube was inserted in the right pleural space, and continuous suction was maintained for 48 hours. The dog was discharged 20 days after surgery and no abnormalities were detected on either blood tests or ultrasonographic examinations of the thorax and abdomen on follow-up examination 7 months after surgery. The presence of a bilothorax should be considered in animals with bile peritonitis, grossly intact diaphragm and pleural effusion. The exact mechanisms of the development of bilothorax are unclear, but the transport of bile through microscopic congenital or acquired weaknesses or defects of the diaphragm, via abdominal lymphatics penetrating the diaphragm and draining into the thoracic lymphatics represent the most probable route.

Current Views in the Diagnosis and Treatment of Intestinal Intussusception.

Intestinal intussusceptions most often occur in young dogs and cats. Common locations for intestinal intussusceptions include enterocolic, eneteroenteric or colocolic. Ultrasonography is highly reliable for diagnosing of intussusception and for prediction of its reducibility. Abdominal structures that may mimic intussuception can be seen ultrasonographically. Intussusceptions is a surgical emergency. Immediate stabilization of the animal followed by manual reduction or intestinal excision of the affected intestine through midline celiotomy are required. Recurrence is a common postsurgical complication. Enteroplication may be considered for recurrence prevention but is not without complications. Prognosis is good in uncomplicated cases.

Quantitative characterization of viscoelastic properties of synovial fluid from forelimb joints of orthopedically normal Thoroughbreds and warmblood horses.

OBJECTIVE: To determine whether differences existed in the viscoelastic properties of synovial fluid samples from the metacarpophalangeal, intercarpal, and distal interphalangeal joints of orthopedically normal athletic horses. ANIMALS: 45 warmblood horses and 30 Thoroughbreds (age range, 4 to 16 years). PROCEDURES: Synovial fluid samples were aseptically obtained via arthrocentesis from 1 metacarpophalangeal, intercarpal, and distal interphalangeal joint of each horse, and nucleated cell counts were performed. A commercial ELISA was used to measure sample hyaluronic acid concentrations, and full rheological characterization of samples was performed to measure the elastic or storage modulus G' and viscous or loss modulus G" at 37.5°C (representing the body temperature of horses). Findings were compared among joints and between breed groups by means of ANOVA. RESULTS: Significant differences in synovial fluid G' and G" values were identified between Thoroughbreds and warmblood horses for the metacarpophalangeal joint, between the metacarpophalangeal and intercarpal joints of Thoroughbreds, and between the metacarpophalangeal and distal interphalangeal joints and intercarpal and distal interphalangeal joints of warmblood horses. No significant differences were identified between breed groups or among joints in synovial fluid hyaluronic concentrations or nucleated cell counts. CONCLUSIONS AND CLINICAL RELEVANCE: Viscoelastic properties of the forelimb joints of orthopedically normal Thoroughbreds and warmblood horses differed within and between these 2 groups, mainly as a function of the evaluated joint. To the authors' knowledge, this was the first study of its kind, and additional research is warranted to better understand the viscoelastic properties of synovial fluid in horses to optimize their locomotive function.

ASSESSMENT OF SENTINEL LYMPH NODE METASTASIS IN CANINE MAMMARY GLAND TUMORS USING COMPUTED TOMOGRAPHIC INDIRECT LYMPHOGRAPHY.

In the staging process of the breast cancer, demonstrating metastasis of the sentinel lymph node (SLN) has an important prognostic value, in both humans and animals. The aim of this prospective case-control study was to determine the diagnostic value of computed tomographic indirect lymphography (CT-LG) for detecting SLN metastasis in dogs with mammary cancer. Thirty-three female dogs with tumors in the abdominal and inguinal mammary glands were prospectively selected and subjected to CT-LG, 1 and 5 min after injection of 1 ml of contrast agent (iopamidol) in the subareolar tissue of the neoplastic and the contralateral normal mammary glands. The pattern of postcontrast opacification, degree of postcontrast enhancement, and size and shape were assessed in 65 SLNs in total and were correlated with histopathological findings. The absence of opacification or heterogeneous opacification 1 min after contrast medium injection showed the highest sensitivity, specificity, and accuracy (93%, 100%, and 98.4%, respectively). In images taken 1 min after injection, an absolute density value lower than 444 Hounsfield units (HU) in the center of the SLN also provided significant sensitivity and specificity (93.8% and 75%, respectively). The size and shape of the SLN (maximum and minimum diameter, maximum/minimum diameter ratio, maximum diameter/height of fifth thoracic vertebral body ratio) showed the lowest sensitivity and specificity. Results of this study support the hypothesis that CT-LG could help in the assessment of SLN metastasis in cases of mammary gland tumors in dogs.

Upper Airway Injury in Dogs Secondary to Trauma: 10 Dogs (2000-2011).

Ten dogs that presented with trauma-induced upper airway rupture or stenosis were reviewed. Tracheal rupture was seen in seven dogs, tracheal stenosis in one dog, and laryngeal rupture in two dogs. Clinical abnormalities included respiratory distress in five dogs, subcutaneous emphysema in eight, air leakage through the cervical wound in seven, stridor in three dogs, pneumomediastinum in four and pneumothorax in one dog. Reconstruction with simple interrupted sutures was performed in four dogs, tracheal resection and end-to-end anastomosis in five dogs, and one dog was euthanized intraoperatively. Complications were seen in three dogs including aspiration pneumonia in one and vocalization alterations in two dogs.

Urothorax Associated with Uroperitoneum in a Dog Without Diaphragmatic Disruption.

Accumulation of urine in the pleural space secondary to uroperitoneum with no disruption of the diaphragm appears to be a rare pathological condition. A 2 yr old male mixed-breed dog was referred with dyspnea and abdominal pain after a road traffic accident. Plain radiographs demonstrated pleural effusion and reduced serosal detail in the abdominal cavity that was compatible with fluid accumulation. Retrograde urethrography revealed a pelvic urethra rupture. Biochemical analysis of the pleural and abdominal fluid confirmed the diagnosis of urothorax and uroperitoneum. The dog underwent a prepubic urethrostomy and intensive care management. The dog was reported to be in good health after a follow up time of 10 mo. To the authors' knowledge, this is the first reported case of urothorax associated with uroperitoneum with no detectable defects of the diaphragm in a dog.

Canine bronchomalacia: a clinicopathological study of 18 cases diagnosed by endoscopy.

Canine bronchomalacia (BM) is characterized by weakness leading to collapse of the bronchial wall. A prospective study of 18 affected dogs (age range: 1-15 years) was undertaken to characterize the clinicopathological and histological features of BM. Poodles and Yorkshire terriers were commonly affected. Half of the dogs were overweight or obese. The clinical presentation was a mild, wheezing, chronic cough and pulmonary crackles were heard in 28% of the dogs. Compatible radiographic changes were present in 61% of the dogs. Using bronchoscopy, both lungs were affected in half of the animals, whereas in the others the disease appeared to affect predominantly the left lung. Analysis of bronchoalveolar lavage fluid and biopsies of bronchial mucosa revealed pure or mixed neutrophilic inflammation. Underlying infectious bronchitis was considered possible in 56% of the dogs. It was concluded that canine BM may present as an isolated clinical entity associated with infection and/or inflammation.

Computed tomography and radiographic indirect lymphography for visualization of mammary lymphatic vessels and the sentinel lymph node in normal cats.

The potential of computed tomography indirect lymphography (CT-indirect lymphography) and radiographic indirect lymphography to demonstrate the draining lymphatic vessels and sentinel lymph node of normal mammary glands was tested in 31 healthy female cats. The lymphatic drainage of each mammary gland was studied initially by CT-indirect lymphography after intramammary injection of 0.5 ml of iopamidol, followed by images acquired at 1, 5, 15, and 30 min after injection. One day after CT-indirect lymphography, the lymph drainage of the mammary gland was assessed using radiographic in direct lymphography af terintramammary injection of 0.5 ml of ethiodized oil followed by radiographs made at 1, 5, 15, 30, 45, and 60 min after injection. The time between intramammary injection and opacification of the draining mammary lymphatic vessels and the sentinel lymph node, the duration of adequate opacification of the draining mammary lymphatic vessels and of the sentinel lymph node and also the number and course of draining mammary lymphatic vessels and location of sentinel lymph node were compared for CT-indirect lymphography vs. radiographic indirect lymphography in each examined gland. This results suggest that radiographic indirect lymphography is easy to perform and can be used for accurate demonstration of the draining lymphatic pathways of mammary glands in radiographs made at 5-30 min after injection. However, CT-indirect lymphography was able to better demonstrate small lymphatic vessels and accurately define the exact topography of the sentinel lymph node in images acquired at 1 min after injection.

Spontaneous reduction of intestinal intussusception in five young dogs.

Five, 3- to 8-month-old dogs had clinical and ultrasonographic findings consistent with intestinal intussusception, but findings were negative on exploratory celiotomy. Ultrasonography had revealed a target-like mass (median maximal diameter 25 mm) on transverse section and multiple hyperechoic or hypoechoic parallel lines (median length 36.8 mm) on longitudinal section. Blood flow in the intussuscepted bowel was detected in most of the cases. In dogs with similar findings, the authors recommend ultrasonographic reexamination of the abdomen after general anesthesia (but before surgery) to exclude spontaneous reduction of the intussusception.

Color Doppler ultrasonography in prediction of the reducibility of intussuscepted bowel in 15 young dogs.

Color Doppler ultrasonography was performed in 15 young dogs with intestinal intussusception to test the hypothesis that color Doppler findings can be used as a predictor of the manual reducibility of the intussusception at celiotomy. Color flow Doppler ultrasonography indicated blood flow within mesentery of the intussuscepted bowel in 12 of 15 dogs and reduction was achieved in nine of these 12 dogs (75%). In the remaining three dogs and in three dogs where no color Doppler signal were observed, an irreducible intussusception was confirmed at celiotomy. Color Doppler ultrasonography is a useful method for predicting the reducibility of intussusception in dogs.

Normal and abnormal ultrasonographic findings that mimic small intestinal intussusception in the dog.

On ultrasonographic examination of the abdomen, the appearance of healthy intestine, enteritis secondary to an intestinal foreign body, and postpartum involution of the uterus may be visualized in some imaging planes as a target-like structure that is subsequently misinterpreted as intestinal intussusception. To avoid misdiagnosis, the ultrasonographer should ensure multi-plane scanning of the lesion, paying particular attention to the completeness of the lesion's peripheral ring structure and the overall width of the concentric rings of the target-like lesion. The presence of a semilunar or G-shaped hyperechoic center and the visualization of the inner intussusceptum (extending into the intussusception lumen) can be useful ultrasonographic findings that distinguish an intussusception from other lesions or from healthy tissues. These principles are illustrated through the following case presentations.

Ultrasonographic signs of intestinal intussusception associated with acute enteritis or gastroenteritis in 19 young dogs.

The ultrasonographic pattern of intestinal intussusception was studied in 19 young dogs with acute enteritis or gastroenteritis. The intussusception was observed to be a target-like mass consisting of a hyperechoic or anechoic center surrounded by multiple hyperechoic and hypoechoic concentric rings in transverse sections. In longitudinal sections, the intussusception appeared as multiple hyperechoic and hypoechoic parallel lines, as a tumor-like or pseudokidney mass, and as a trident-like configuration. Ultrasonography may provide a sensitive, specific, and accurate method of diagnosing intestinal intussusception in young dogs.