Ultrasonographic findings of intestinal intussusception in seven cats

The medical records of seven cats with intestinal intussusception that were diagnosed by abdominal ultrasonography and exploratory laparotomy were reviewed. In transverse ultrasonographic sections the intussusception appeared as a target-like mass consisting of one, two or more hyperechoic and hypoechoic concentric rings surrounding a C-shaped, circular or non-specific shaped hyperechoic centre. Part of the intestine representing the inner intussusceptum, located close to the hyperechoic centre and surrounded by concentric rings, was also detected. In longitudinal sections the intussusception appeared as multiple hyperechoic and hypoechoic parallel lines in four cases and as an ovoid mass in three cases. In one case the ovoid mass had a ‘kidney’ configuration. Additional ultrasonographic findings associated with intestinal intussusception included an intestinal neoplasm in one cat. The results of the present study demonstrate that the ultrasonographic findings of intestinal intussusception in cats bear some similarities to those described in dogs and humans, are relatively consistent, and facilitate a specific diagnosis.     

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.     

Ultrasonographic diagnosis of small-intestinal intussusception in three foals

Small-intestinal intussusceptions were diagnosed in 3 foals. Cross-sectional ultrasonography through the apex of the intussusceptum revealed a target-like pattern with a thick hypoechoic rim. The thick hypoechoic rim was caused by severe edema of the entering and returning walls of the intussusceptum. At the more proximal portion of the intestines, where parietal edema was less severe, the image appeared as 2 concentric rings and an inner circular area. The outer ring and inner circular area were hypoechoic and represented the returning and the entering wall of the intussusceptum. An additional cross-sectional pattern can be described as double concentric rings, with the inner lumen represented by a central echogenic core. Longitudinal scannings of the involved intestinal section revealed a different view of the same anatomic situation, with 2 hyperechoic areas delineated by 3 stripes of hypoechoic intestine. Ultrasonography of a foal's abdomen provides a clinician with a rapid noninvasive technique that may aid in the differential that may aid in the differential diagnosis of colic. The ultrasonographic diagnosis of intussusception may improve the recognition of a surgical lesion and improve the potential for successful treatment.     

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.     

Acute enteritis or gastroenteritis in young dogs as a predisposing factor for intestinal intussusception: a retrospective study

Various types of intestinal intussusception were diagnosed in 29 of 220 young dogs with acute enteritis or gastroenteritis, due to canine parvovirus (85 cases) or presumably to other infectious agents, inflammation or less common hypermotility and metabolic derangements (135 cases). As the other causes of the disease were excluded, acute enteritis or gastroenteritis was considered to be the most likely predisposing factor for the intestinal intussusception. The most common type of intussusception was found to be the ileocolic. Of the 21 dogs that underwent surgical resection and anastomosis of the intestine, 18 dogs recovered completely and three died due to complications. The high survival rate was due to the effective pre-operative, surgical and post-operative therapy.     

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.     

X-ray-computed tomography, nephrotomography, and ultrasonography of the adrenal glands of healthy dogs

X-ray-computed tomography (CT), nephrotomography, and ultrasonography were performed in 10 clinically healthy dogs (weighing 14 to 33 kg) to visualize the adrenal glands. In all 10 dogs, CT enabled visualization of both adrenal glands. Cross-sectional diameter was measured accurately. The size and shape of CT sections of the adrenal glands varied widely because of individual differences in the actual size and shape of the adrenal glands and because of their position in the plane of the CT scans. In 5 dogs, nephrotomography enabled visualization of 1 or both adrenal glands as oblong craniocaudal-directed densities in the craniodorsal portion of the abdomen. In 7 dogs, transverse ultrasonography enabled visualization of 1 or both adrenal glands as round or oval hypoechoic structures in the surrounding hyperechoic fat.     

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.     

RADIOGRAPHIC AND ULTRASONOGRAPHIC FEATURES OF RETAINEDSURGICAL SPONGE IN EIGHT DOGS

The radiographic and ultrasonographic signs in eight dogs with a surgical or pathologic diagnosis of retained surgical sponge were reviewed. The most frequent previous surgery was ovariohysterectomy, either as an elective procedure or to treat pyometra. The median elapsed time between surgery and diagnosis of retained surgical sponge was 9.5 months (range 4 days to 38 months). Five dogs had a draining sinus; four had a palpable abdominal mass. Radiologic signs included localized, speckled or whirl-like gas lucency, abdominal mass, and non-focal soft tissue swelling. Survey radiography and sinography were considered diagnostic for retained surgical sponge in 4/7 (57%) and 3/5 (60%) dogs, respectively. The combined use of survey radiography and sinography enabled detection of 6/7 (86%) sponges. In each dog that had ultrasonography, a hypoechoic mass was found that had an irregular hyperechoic centre. The possibility of retained surgical sponge should be considered in animals with a history of previous surgery and a sinus or abdominal mass.     

ULTRASONOGRAPHIC FEATURES OF INTESTINAL ENTRAPMENT IN DOGS

The clinical and ultrasonographic features of postoperative intestinal entrapment were assessed in five dogs. Four had vomiting and lethargy, and one had peracute collapse and hematochezia. Ultrasonographic findings in four of five dogs were similar, being characterized by focally hyperechoic mesentery and abdominal effusion, surrounding a single loop of amotile and dilated intestine. In some dogs, the affected intestinal loop had a thickened or corrugated wall, or alteration of wall layering. In one dog, the site of entrapment could be directly visualized. In the most severely affected dog, a large volume of echogenic peritoneal effusion was present, as well as fluid dilation of multiple intestinal loops. The ultrasonographic appearance of intestinal entrapment is similar to that of intestinal perforation or infarction by other causes.     

Ultrasonographic features of splenic hemangiosarcoma in dogs: 18 cases (1980-1986)

The medical records of 18 dogs in which ultrasonography was useful in making a diagnosis of splenic hemangiosarcoma were reviewed. Splenic ultrasonography revealed masses with echo patterns that ranged from anechoic fluid to hyperechoic tissue. In 7 dogs, metastasis was detected ultrasonographically as anechoic to hypoechoic lesions in the liver.     

Correlation of ultrasonographic and patho-morphological findings in canine hepatic diseases

Findings of hepatic ultrasonography were analysed in 22 dogs with liver disease and compared with the results of final morphological diagnoses. Ultrasonographic appearance of the liver demonstrated focal alterations in 11 dogs (50 per cent): multifocal lesions in hepatic neoplasia (six), hepatic cirrhosis (one), generalised mycosis (one) and unifocal lesions in haemangiosarcoma (one), nodular hyperplasia (one) and misdiagnosed intestinal invagination (one), Diffuse ultrasonographic alterations were found in 11 dogs (50 per cent): hyperechoic liver of normal/enlarged size in lymphosarcoma (four) and hepatic lipidosis (two); hyperechoic ‘bright’ but small liver in atrophic cirrhosis (two); hypoechoic to normal intensity liver of normal size in liver dystrophy (two) and hepatic venous distension (one). Gallbladder abnormalities were detected in 14 of 20 dogs (70 per cent). Correct ultrasonographic diagnoses were made in 11 dogs (50 per cent). The best results were achieved by combining the clinicolaboratory and ultrasonographic findings, providing a correct diagnosis in 17 dogs (77-3 per cent).     

Intussusception in dogs and cats: A review of 36 cases

Intussusception is recognized as a common cause of bowel obstruction in small animals. This study documents the clinical and surgical findings in nine cats and 27 dogs diagnosed as having intussusception. The main purposes of the study were to define the predisposing causes and clinical signs of intussusception and to evaluate various surgical techniques commonly employed in its treatment. No common predisposing cause could be established. Diagnosis of intussusception was based most often on clinical signs of bowel obstruction in association with the palpable abdominal mass. The majority of the intussusceptions involved the enterocolic junction. Formation of adhesions was more frequent in cats. Surgical treatments included simple reduction, manual reduction with plication, intestinal resection/anastomosis, and intestinal resection/anastamosis with plication. There was no statistically significant difference (p>0.05) in the recurrence rate of the intussusceptions when the various surgical techniques were compared. Recurrence of an intussusception was not related to either the bowel segment involved or whether a simple reduction, bowel resection, or intestinal plication was performed at the initial surgery.     

Comparison of ultrasonographic findings with clinical activity index (CIBDAI) and diagnosis in dogs with chronic enteropathies.

Intestinal wall thickness is neither a specific nor sensitive ultrasound parameter for detecting intestinal inflammation. We hypothesize that mucosal echogenicity, lymphadenomegaly, and secondary findings of the gastrointestinal tract would be more sensitive and specific markers for detecting and differentiating causes of chronic inflammatory bowel disease in dogs. Fifty-six client-owned dogs with chronic diarrhea and 10 control dogs were examined with two-dimensional, gray-scale ultrasound (time 0, 4, and 10 weeks post therapy) and small intestinal mucosal biopsies were performed at the 0- and 4-week time points. The clinical activity was assessed at each time point using the canine inflammatory bowel disease activity index (CIBDAI). Fifty-one dogs had inflammatory infiltration of the duodenal mucosa and were divided into three groups, food-responsive disease, idiopathic inflammatory bowel disease, and protein-losing enteropathy, based on their response to the different treatments and histology. Two different patterns of increased echogenicity of the mucosa were detected: hyperechoic speckles and hyperechoic striations. A normal, hypoechoic bowel mucosa in dogs with chronic diarrhea had a sensitivity of 80% and a specificity of 81% for the diagnosis of food-responsive disease. Hyperechoic striations had a sensitivity of 75% and a specificity of 96% for dogs with protein-losing enteropathy. Hyperechoic speckles were non-specific for diagnosing inflammatory bowel disease. There was a significant relationship between ultrasound score and CIBDAI at t0, but not following therapy. Mucosal echogenicity may be a better parameter for detecting inflammatory bowel disease than bowel wall thickness in dogs with chronic diarrhea.     

TESTICULAR ULTRASOUND IN THE NORMAL DOG

The testicles of ten dogs presented for routine castration were imaged with real time ultrasound. A scanning technique using multiple imaging planes (sagittal, transverse, and dorsal planes) was developed to image the testicles and epididymi. The testes were characterized by a coarse medium echo pattern. The mediastinum testis was consistently seen as a 0.2 cm wide linear hyperechoic structure in the central long axis of the testis. The ability to identify and the appearance of the epididymis was variable. The tail was consistently seen as an anechoic to hypoechoic structure. Ultrasound images were compared for anatomical structure with frozen gross sections. Ultrasonic and gross measurements were made and analyzed. Individual gross and ultrasonic measurements compared favorably. Linear regression coefficients between body surface area versus testicular length and diameter were 0.73 and 0.58 respectively. A Wilcoxin signed rank test for similarity p = 0.33 value was found when comparing the right to the left testicle.     

ULTRASONOGRAPHIC FEATURES OF CANINE ABDOMINAL MALIGNANT HISTIOCYTOSIS

Ultrasonographic features of canine abdominal malignant histiocytosis (MH) of 16 dogs are reported. The most common finding was the presence of hypoechoic nodules in the spleen, some of which caused distortion of the splenic margin. The liver was the second-most commonly affected organ. Hepatic ultrasonographic features were highly variable, including hypoechoic, hyperechoic, or mixed echogenic lesions. Other common ultrasonographic abnormalities included hypoechoic nodules in the kidneys and mesenteric and medial iliac lymphadenopathy. The results of this study suggest that the ultrasonographic appearance of canine abdominal MH is nonspecific, and definitive diagnosis requires cytologic or histologic examination.     

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.     

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 .     

Ocular complications of persistent hyperplastic primary vitreous in three dogs

Persistent hyperplastic primary vitreous (PHPV) syndrome associated with either severe ocular complications or multiple ocular lesions was diagnosed in three young dogs, a Samoyed, a Spanish Pachon, and a mixed breed dog. Due to opacification of the anterior ocular structures, B-mode and color-flow Doppler ultrasonography were performed to aid diagnosis. The Samoyed presented with unilateral hyphema; the Spanish Pachon presented with unilateral secondary glaucoma associated with uveitis and hyphema OD and leucocoria OU; and the mixed breed presented with bilateral leucocoria. B-mode ultrasonography of the Samoyed revealed a subcapsular cataract and a hyperechoic tubular structure attached from the optic disk to the posterior lens capsule. In the Spanish Pachon B-mode ultrasonography of the right eye indicated microphakia, cataract formation, and a retrolental mass with a thin hyperechoic strand stretching from the optic disk to the posterior lens; and for the right eye cataract formation, PHPV, retinal detachment, and vitreous hemorrhage. In the mixed breed dog, B-mode ultrasonography of both eyes indicated microphthalmia, retrolental mass, and hyperechoic lenses. By color-flow Doppler imaging, blood flow was present in the retrolental mass of the right eye suggesting a persistent hyaloid artery.