CONTRAST‐ENHANCED ULTRASONOGRAPHY OF THE PANCREAS IN HEALTHY DOGS AND IN DOGS WITH ACUTE PANCREATITIS

Pancreatitis is the most frequent disease affecting the exocrine pancreas in dogs and reliable diagnostic techniques for predicting fatal complications are lacking. Contrast‐enhanced ultrasound (CEUS) improves detection of tissue perfusion as well as organ lesion vascular pattern. Objectives of this prospective case control study were to compare perfusion characteristics and enhancement patterns of the pancreas in healthy dogs and dogs with pancreatitis using CEUS. Ten healthy dogs and eight dogs with pancreatitis were selected based on physical examination, abdominal ultrasound, and blood analysis findings. A CEUS study of the pancreas was performed for each dog and two observers who were aware of clinical status used advanced ultrasound quantification software to analyze time‐intensity curves. Perfusion patterns were compared between healthy and affected dogs. In dogs with acute pancreatitis, mean pixel and peak intensity of the pancreatic parenchyma was significantly higher than that of normal dogs (P = 0.05) in between 6 and 60 s (P = <0.0001–0.046). This corresponds to a 311% increase in mean pixel intensity in dogs with acute pancreatitis compared to healthy dogs. Wash‐in rates were greater and had a consistently steeper slope to peak in dogs with pancreatitis as opposed to healthy dogs. All dogs with pancreatitis showed a decrease in pixel intensity 10–15 days after the initial examination (P = 0.011) and their times to peak values were prolonged compared to the initial exam. Findings from the current study supported the use of CEUS for diagnosing pancreatitis, pancreatic necrosis, and disease monitoring following therapy in dogs.     

EFFECTS OF CORN OIL ADMINISTERED ORALLY ON CONSPICUITY OF ULTRASONOGRAPHIC SMALL INTESTINAL LESIONS IN DOGS WITH LYMPHANGIECTASIA

Lymphangiectasia is one of the causes of protein‐losing enteropathy in dogs and characteristic ultrasonographic small intestinal lesions have been previously described. The purpose of this study was to determine whether corn oil administered orally (COAO) would result in increased conspicuity of these characteristic small intestinal ultrasonographic lesions in dogs with lymphangiectasia. Affected dogs were included if they underwent corn oil administered orally and had a surgical full‐thickness intestinal biopsy diagnosis of lymphangiectasia. Control dogs had normal clinical examination and standard laboratory test findings. Ultrasound images of duodenum, jejunum, and ileum were obtained prior to and 30, 60, 90, and 120 min after corn oil administered orally for all dogs. Parameters recorded for each ultrasound study were intestinal wall thickness, mucosal echogenicity, and presence or absence of hyperechoic mucosal striations (HMS) and a parallel hyperechoic mucosal line (PHML). Nine affected and five controls dogs were included in the study. Seven of the nine dogs with lymphangiectasia had hyperechoic mucosal striations prior to corn oil administered orally. Jejunal hyperechoic mucosal striations were significantly associated with lymphangiectasia at multiple time points (P < 0.05) and were best identified in dogs with lymphangiectasia 60 or 90 min after corn oil administered orally. Increased mucosal echogenicity was observed in all dogs at multiple time points after corn oil administered orally. A parallel hyperechoic mucosal line was present in the jejunum in 4/5 healthy and 6/9 dogs with lymphangiectasia at one or more time points after corn oil administered orally. Findings indicated that corn oil administered orally improves conspicuity of characteristic ultrasonographic lesions in dogs with lymphangiectasia, however some of these lesions may also be present in healthy dogs that recently received a fatty meal.     

AGE-RELATED CHANGES IN THE ULTRASOUND APPEARANCE OF THE NORMAL FELINE PANCREAS

In humans, pancreatic hyperechogenicity and duct dilation are reported as normal aging changes. Similar changes have been reported with pancreatitis in the cat. We attempted to determine if aging changes occur in the ultrasound appearance of the normal feline pancreas. The pancreas of 84 normal (based on history, physical exam, biochemical profile, and feline trypsin-like immunoreactivity and pancreatic lipase immunoreactivity concentrations) cats of varying ages was scanned. Pancreatic width at the left limb and body, pancreatic duct diameter at left limb and body, and pancreatic echogenicity compared with liver and surrounding fat were noted and compared with age and body weight. Lower and upper limits of the 95% reference intervals for pancreatic left limb width were 2.6 and 9.5 mm, and 3.5 and 8.5 mm for the pancreatic body width. There was no significant difference in pancreatic width between the left limb and body. Lower and upper limits of the 95% reference interval for the diameter of the pancreatic duct at the left limb and body were similar, and were 0.65 and 2.5 mm. There was a weak but significant linear correlation between pancreatic duct diameter and age, with increasing pancreatic duct diameter with increasing age. There was no correlation of pancreatic width with age, and no correlation of pancreatic echogenicity with age or body weight. Based on this study, feline pancreatic size and echogenicity do not change with age. Pancreatic duct diameter increases slightly with age and should not be used as a sole indicator of pancreatitis in the geriatric cat.     

Do Thyroid Ultrasonographic Features Change According to Age in Euthyroid Dogs?

The thyroid gland was assessed by ultrasound in healthy euthyroid mixed‐breed medium size dogs in different age groups. The objective was to verify ultrasonographic imaging patterns in these groups, as well as to identify possible changes in imaging features resulting from ageing. Thirty dogs – 10 young (<1 year), 10 adult and 10 elderly – without clinical signs or history of thyroid gland disease with complete blood count and thyroid function tests within the reference values were evaluated. Each thyroid lobe was examined by ultrasound for shape, size, echogenicity and echotexture. The analysis of echogenicity and echotexture was made by histogram. Thyroid volume was estimated by the equation for ellipsoid (length × width × height) π/6. The thyroid volume of the young dogs in this study had a tendency to be higher than in adult dogs (P = 0.068) and older dogs (P = 0.120). The height of the thyroid lobe in the longitudinal plane was significantly higher (P = 0.026) in young dogs compared with the other dogs. The echotexture and echogenicity had no significant differences between groups, but the echogenicity was greater in older dogs. The results point out that ultrasound imaging of the thyroid volume is influenced by age in euthyroid dogs.     

ENDOSCOPIC ULTRASONOGRAPHIC FINDINGS OF THE PANCREAS AFTER PANCREATIC DUCT LIGATION IN THE DOG

Endoscopic ultrasonographic evaluation and gray-scale histogram analysis of pancreatic atrophy after pancreatic duct ligation were performed in four normal adult dogs. Using endoscopic ultrasonography, markedly dilated pancreatic ducts were visualized, and the pancreas became gradually atrophied with a hyperechoic parenchyma. In gray-scale histogram analysis of the pancreas, mean brightness increased gradually until 8 weeks, then decreased temporally. Standard deviation of the histogram increased markedly and then fluctuated until the 4th week, after which the mean brightness and standard deviation became stable. At 4 weeks postoperatively, collapse of most pancreatic acinar structures were observed, and each atrophic lobule was associated with a significantly large amount of interstitial fibrous tissue at histopathology. At 12 weeks postoperatively, most exocrine tissue had decreased and was partly replaced by fibrous and fatty tissue. These changes of mean brightness and standard deviation reflected the histologic analysis. These findings indicated that endoscopic ultrasonography is a useful technique to image such atrophic disorders of the pancreas as chronic pancreatitis. Furthermore, gray-scale histogram analysis provides helpful information for ultrasonographic tissue characterization of the pancreas.     

PREVALENCE OF GALLBLADDER SLUDGE IN DOGS AS ASSESSED BY ULTRASONOGRAPHY

Ultrasonography of the gallbladder was performed in 3 groups of dogs: 30 clinically healthy dogs, 50 dogs with hepatobiliary disease, and 50 dogs with diseases other than hepatobiliary disease. The gallbladder was evaluated for the presence of sludge (echogenic material without acoustic shadowing). Maximal gallbladder length, width, height, and area were measured as well as the gallbladder wall thickness. The relative sludge area was calculated as the ratio of sludge area over gallbladder area on longitudinal images. No significant difference was found in the prevalence of gallbladder sludge among healthy dogs (53%), dogs with hepatobiliary diseases (62%), and dogs with other disease (48%). The mean age of dogs with sludge was higher than the mean age of dogs without sludge in dogs with hepatobiliary disease and dogs with other diseases (p ≤0.05). The mean relative sludge area did not differ significantly among the 3 groups. A trend to larger gallbladder dimensions in dogs with sludge compared to dogs without sludge was detected within the 3 groups. The gallbladder wall thickness was not different between dogs with and without sludge within the 3 groups. However, the gallbladder wall was more frequently isoechoic than hyperechoic to the liver in dogs with sludge than in dogs without sludge. The results of this study indicate that gallbladder sludge, in dogs, in not particularly associated with hepatobiliary disease and should be considered an incidental finding.     

ABDOMINAL ULTRASONOGRAPHIC FINDINGS IN DOGS NATURALLY INFECTED WITH BABESIOSIS

Canine babesiosis is a tick‐borne disease with a worldwide distribution that can involve multiple organs and result in a wide variety of clinical manifestations. Our goal was to describe the sonographic changes occurring in 72 dogs naturally infected with babesiosis. Seven healthy Beagle dogs were used as a control group. The most common finding in all dogs was splenomegaly with a diffuse heterogenic parenchyma and generally reduced echogenicity. Diffuse hypoechoic hepatomegaly and bilaterally increased cortical echogenicity of the renal parenchyma were found more frequently in severe uncomplicated and complicated babesiosis groups. Mean renal resistive index and pulsatility index (PI) values were 0.66/1.35, 0.73/1.91, and 0.71/1.73 for mild uncomplicated, severe uncomplicated, and complicated babesiosis groups, respectively. A markedly increased PI for complicated and severe uncomplicated groups correlated with anemia and severity of renal damage. Ultrasonography can be an adjunct for diagnosis and monitoring canine babesiosis and its systemic complications. The detection of diffuse heterogeneous splenomegaly can support the diagnosis of Babesia infection, because of the high prevalence of this lesion in these patients.     

Thyroid sonography as an effective tool to discriminate between euthyroid sick and hypothyroid dogs

The diagnosis of canine hypothyroidism and its differentiation from euthyroid sick syndrome still is a major diagnostic challenge. In this study, ultrasonography was shown to be an effective tool for the investigation of thyroid gland diseases. Healthy control dogs (n = 87), dogs with euthyroid sick syndrome (n = 26), thyroglobulin autoantibody-positive (TgAA-positive, n = 30) hypothyroid dogs, and TgAA-negative (n = 23) hypothyroid dogs were examined by thyroid ultrasonography. Maximal cross sectional area (MCSA), thyroid volume, and echogenicity were measured. Statistical analysis identified highly significant (P < .001) differences between euthyroid and hypothyroid dogs both in thyroid volume and in MCSA, whereas no significant differences in thyroid size were detected between healthy euthyroid dogs and dogs with euthyroid sick syndrome. In euthyroid and euthyroid sick dogs, parenchymal echotexture was homogeneous and hyperechoic, whereas relative thyroid echogenicity of both TgAA-positive and TgAA-negative hypothyroid dogs was significantly lower (P < .001). When using arbitrarily chosen cutoff values for relative thyroid volume, MCSA, and echogenicity, thyroid volume especially was found to have highly specific predictive value for canine hypothyroidism. In summary, the data reveal that thyroid sonography is an effective ancillary diagnostic tool to differentiate between canine hypothyroidism and euthyroid sick syndrome.     

ENDOSCOPIC RETROGRADE CHOLANGIO-PANCREATOGRAPHY IN DOGS WITH CHRONIC GASTROINTESTINAL PROBLEMS

Endoscopic retrograde cholangio-pancreatography is a combination of endoscopy and fluoroscopy used for radiographic imaging of the biliary and pancreatic ducts. In order to assess its feasibility and to describe abnormal findings in dogs, this technique was performed in 30 dogs with nonspecific chronic gastrointestinal disturbances. Using an 11-mm side-view endoscope, retrograde cholangiography was successful in 20/30 dogs (67%) and pancreatography in 21/30 (70%). Success was affected by intraduodenal food, mucus or blood, problems in papillary cannulation, stomach overdistention, body size, and changes in duodenal mucosa. It was impossible to perform the procedure in dogs weighing < 10 kg with the available material. Endoscopic retrograde cholangiography revealed findings that differed from previous reports in healthy beagles in 5/20 dogs. Findings included enlarged common bile duct (n = 2), intraductal filling defects (n = 2), and deviated course of common bile duct (n = 1), and major papilla stenosis (n = 1). In the dog with major papilla stenosis and intraductal filling defects, endoscopic guided sphincterotomy was performed. Endoscopic retrograde pancreatography revealed an abnormal course of the accessory pancreatic duct in 2/21 dogs. In both dogs with proven end-stage pancreatic acinar atrophy, the left duct branch did not run distal the stomach to the left but went parallel to the right duct branch and the duodenum. Repeated clinical and laboratory examinations revealed no signs of complications after endoscopic retrograde cholangio-pancreatography. It was concluded that this imaging technique is promising for the diagnosis of biliary and pancreatic diseases in dogs. It also offers the chance for new treatment options such as endoscopic guided sphincterotomy in dogs.     

EX VIVO CORRELATION OF ULTRASONOGRAPHIC SMALL INTESTINAL WALL LAYERING WITH HISTOLOGY IN DOGS

Canine ultrasonographic intestinal layers have been reported to correlate with histological layering. However, discrepancies have been reported in people, and additional layers visualized. The aim of this method comparison study was to describe ex vivo canine small intestinal layering and correlate it with histology. Small intestinal samples of 12 adult dogs euthanized for reasons unrelated to gastrointestinal disease were resected immediately following euthanasia, pinned on a Petri dish, and transverse ultrasonographic images acquired in a water bath, using a high‐frequency linear transducer. Transverse histological sections were obtained at the same level. Measurements of the intestinal layers were performed on the ultrasonographic and histological images. No significant statistical differences were noted between the ultrasonographic and histological measurements and strong to very strong (r > 0.7) positive correlation was observed for all layers, except for the serosa, which had a low moderate positive correlation (r = 0.479). In addition to the five established layers, a dual mucosal echogenicity was consistently observed, with seven samples presenting an additional inner mucosal severe hyperechogenicity. Histologically, this dual echogenicity was attributed to the intestinal villi (mildly echogenic) and lamina propria (hypoechoic). The additional inner mucosal severe hyperechogenicity observed in seven samples was attributed to mild‐to‐moderate lacteal dilation histologically. In 4/12 ileal samples, an additional hyperechoic mucosal line was also observed parallel to the submucosa, corresponding histologically to prominent Peyer's patches. Finally, a hyperechoic line was observed within the muscularis of all samples, corresponding histologically to the interface between the muscularis longitudinal and circular layers .     

ENDOSCOPIC ULTRASONOGRAPHY OF THE PANCREAS IN THE DOG

Endoscopic ultrasonography was done in 12 normal adult dogs to investigate its efficacy in visualization of the pancreas. The endoscopic ultrasonographic device used in the present study had a curved-array ultrasound transducer mounted in front of the objective lens. The tip of the ultrasonic endoscope was inserted into the stomach, and all examinations of the pancreas were performed from within the stomach. Endoscopic ultrasonography provided good images of most parts of the pancreas except for the ends of each lobe. Useful information about the pancreatic parenchyma, including pancreatic lobular structure, pancreatic duct, and vessels of the pancreas was obtained by endoscopic ultrasonography. Blood flow within vessels was detected using color Doppler and pulsed-wave Doppler examination. These results suggest that endoscopic ultrasonography is available as an effective diagnostic modality in small animal practice.     

PREVALENCE AND SIGNIFICANCE OF AN ULTRASONOGRAPHIC COLONIC MUSCULARIS HYPERECHOIC BAND PARALLELING THE SEROSAL LAYER IN DOGS

The muscularis layer of the canine colon has been reported to appear homogeneously hypoechoic on ultrasonography. A hyperechoic band in the muscularis layer paralleling the serosal surface has been observed by authors in routine canine abdominal ultrasound examinations. The purpose of this prospective and retrospective cross‐sectional study was to determine the prevalence of this lesion, characterize its ultrasonographic and postmortem histologic features, and correlate its presence with clinical signs of gastrointestinal disease. In the prospective study, all dogs that underwent routine abdominal ultrasonography by one of two observers during a 4‐week period were included without any exclusion criteria. One observer reviewed ultrasound images and recorded the presence or absence of this lesion and its distribution, e.g. focal (< 2 cm long) or diffuse (> 2 cm long). In the retrospective study, all dogs that had both abdominal ultrasonography and necropsy from January 2011 to December 2013 were included without any exclusion criteria. Histologic examinations were performed by two observers and Masson's trichrome stain was used to identify fibrous collagen. Prevalence for the hyperechoic band was 32% in the prospective and 4.8% in the retrospective sample populations, respectively. The hyperechoic band appeared as diffuse, focal, or a combination of both. Histologic sections were available for six dogs. In a few cases, the lesion corresponded to the presence of fibrous tissue in the myenteric plexus or in the tunica muscularis. None of the dogs had a history of diarrhea. Findings supported the hypothesis that a colonic muscularis hyperechoic band paralleling the serosal layer in dogs could be a normal variant rather than a marker of disease.     

HEPATIC ABSCESSES IN 13 DOGS: A REVIEW OF THE ULTRASONOGRAPHIC FINDINGS, CLINICAL DATA AND THERAPEUTIC OPTIONS

Historical, physical examination, clinicopathologic, radiographic and ultrasonographic findings of 13 dogs with hepatic abscesses were reviewed. Liver abscessation was characterized by number, size, shape, echogenicity and location. Solitary lesions greater than 3 cm were more common than multiple ones. The abscesses were mainly poorly echogenic lesions, often with central cavitation. The shape of the lesion ranged from round to oval or irregular. Enhancement artifact, abdominal effusion, regional lymphadenopathy and hyperechoic perihepatic fat, were identified in several dogs. Ultrasound-guided aspiration was performed in 10 of 13 dogs, and confirmed abscessation with cytologic and microbiologic evaluation. Ultrasound-guided percutaneous drainage of abscesses was performed as an adjunct to medical management in four dogs.     

CONTRAST‐ENHANCED ULTRASONOGRAPHIC FINDINGS IN THREE DOGS WITH PANCREATIC INSULINOMA

Abdominal ultrasonography is one of the most common diagnostic imaging modalities used for dogs with suspected insulinoma; however, pancreatic masses are clearly identified in fewer than half of affected dogs and benign pancreatic nodules can be difficult to differentiate from malignant ones. The purpose of this prospective study was to describe contrast‐enhanced ultrasonography (CEUS) characteristics of confirmed pancreatic insulinoma in a group of dogs. Inclusion criteria were as follows: (1) repeated hypoglycemia (blood glucose levels <60 mg/dl, twice or more); (2) elevated blood insulin levels with hypoglycemia; (3) pancreatic nodules detected with conventional ultrasonography; and (4) histological confirmation of pancreatic islet cell carcinoma. Immediately following conventional ultrasonography of the entire abdomen, CEUS of the pancreatic nodule and adjacent parenchyma was performed using contrast‐specific technology pulse inversion imaging and perflubutane microbubble contrast agent. Three dogs met inclusion criteria. Pancreatic nodules in all the three dogs became more clearly demarcated after injection of the contrast agent. Each nodule showed different enhancement patterns: markedly hyperechoic for 5 s, slightly hyperechoic for 1 s, and clearly hypoechoic for over 30 s. These results were not in complete agreement with previously reported CEUS findings in human patients with insulinoma. All nodules were surgically resected and histopathologically confirmed as malignant insulinomas. Findings from the current study indicated that contrast‐enhanced ultrasound may help to increase conspicuity of pancreatic insulinomas in dogs and that enhancement characteristics may be more variable in dogs than in humans.     

CLINICAL AND ULTRASONOGRAPHIC CHARACTERISTICS OF SALIVARY MUCOCELES IN 13 DOGS

Salivary mucocele is one of the causes of submandibular swelling in dogs and is due to a collection of mucoid saliva that has leaked from a damaged salivary gland. The purpose of this case series report was to describe the clinical and ultrasonographic characteristics of confirmed salivary mucoceles in 13 dogs admitted to the Faculty of Veterinary Medicine at Cairo University. The final diagnosis of salivary mucocele was based on aspirate cytology for all dogs and additional surgical excision for seven dogs. For dogs admitted from 2 weeks to 1 month from the onset of clinical signs, the cervical mucocele appeared as a round echogenic structure with a large volume of central anechoic content. The wall was a clearly identified hyperechoic structure surrounding the gland. For dogs admitted between 1 to 2 months from the onset of clinical signs, the volume of anechoic material appeared less than that seen in the acute cases. The overall appearance of the salivary mucocele was heterogenous. For dogs admitted after 2 months from the onset of clinical signs, the salivary mucocele appeared grainy or mottled, with a heterogenous appearance and a further decrease in anechoic content. For one dog that presented after 3 months from the onset of clinical signs, the salivary mucocele was hard on palpation and appeared hyperechoic with distal acoustic shadowing. Findings from this study indicated that ultrasonographic characteristics of salivary mucoceles in dogs vary depending on the chronological stage of the disease.     

THE PREVALENCE OF DIROFILARIA IMMITIS AND OTHER PARASITES IN URBAN POUND DOGS IN NORTH-EASTERN VICTORIA

SUMMARY The results of a survey investigating the prevalence of dirofilaria immitis and other helminth and protozoan infections in urban dogs in north-eastern Victoria are presented. D. immitis was detected in 2.7% of the general population (8.3% of dogs older than 2 years). Microfilariae of D. immitis were not detected in the peripheral circulation of 30% of dogs infected with the adult parasites. The most prevalent gastro-intestinal parasites were Dipylidium caninum 57%; Trichuris vulpis 41%; Toxocara canis 38%; and Uncinaria stenocephala 26%. The prevalence of T. canis in dogs less than one year of age was 73% and this decreased with increasing age. No Echinococcus granulosus adults were detected. Sarcocystis spp and Isospora ohioensis were the most commonly seen coccidians.     

ULTRASONOGRAPHIC FEATURES OF PYONEPHROSIS IN DOGS

Pyonephrosis refers an infected hydronephrotic kidney which arise from pyelonephritis followed by exudate accumulation in a dilated renal pelvis or hydronephrosis followed by ascending infection. Pyonephrosis may cause serious systemic complications, making prompt and reliable diagnosis critical. Clinical and ultrasonographic findings are used for the diagnosis of pyonephrosis in humans, but these findings have not been investigated in dogs. We reviewed ultrasonographic features in pyonephrosis in 18 dogs. Ten dogs with hydronephrosis were also evaluated to compare with the pyonephrosis patients. In most dogs with pyonephrosis, hyperechoic contents completely filled the dilated renal pelvis (n=8) or a fluid‐debris level was observed (n=8). Hyperechoic contents were dispersed in renal pelvis in only two of the 18 dogs. Hyperechoic, edematous mesentery, and peritoneal and retroperitoneal effusion, which represented peritoneal and retroperitoneal inflammation, were observed in the perinephric region in 11 dogs. Compared with pyonephrosis, and as expected, hydronephrosis was characterized by anechoic contents within the urine‐filled collecting system and there were no definitive findings to suspect peritonitis. Thus, there is a distinct difference in the sonographic appearance of pyonephrosis vs. hydronephrosis in dogs.     

ULTRASONIC EXAMINATION OF THE PANCREAS IN HEALTHY COWS

The purpose of this study was to describe the ultrasonographic appearance of the normal bovine pancreas and to establish reference values for healthy cattle. Ultrasonographic examinations were performed on the right side of 20 healthy cows. Ultrasonographically the body and right limb of pancreas appeared as a triangle-shaped structure associated with the liver, portal vein, right kidney, and duodenum. In comparison to normal liver, the pancreas appeared isoechoic or slightly more echogenic. The right lobe of the pancreas was evaluated from the right flank to the eleventh intercostal space, and the body of the pancreas was visualized from the twelfth to the tenth intercostal space. The left lobe of the pancreas could not be seen because of its dorsomedial location. In 9 cows, the accessory pancreatic duct was located near the right lobe of the pancreas and appeared as two parallel echogenic lines with a hypoechogenic area between them. The diameter of the accessory pancreatic duct varied from 6 to 8 mm. The pancreaticoduodenal vein was seen in 5 cows. The diameter of the pancreaticoduodenal vein varied from 3 to 4 mm. The ultrasonographic characteristics determined in this study may serve as a reference in the evaluation of cows with suspected pancreatic disease.