Clinical, clinicopathologic, radiographic, and ultrasonographic characteristics of intestinal lymphangiectasia in dogs: 17 cases (1996-1998)

OBJECTIVE: To characterize the clinical, clinicopathologic, and imaging findings in dogs with intestinal lymphangiectasia and to compare the histologic grade of lymphangiectasia with clinicopathologic and imaging abnormalities. DESIGN: Retrospective study. ANIMALS: 17 dogs with a histologic diagnosis of intestinal lymphangiectasia. PROCEDURE: Medical records of dogs with a histologic diagnosis of intestinal lymphangiectasia were reviewed for signalment, history, clinical signs, results of exploratory laparotomy, and clinicopathologic, radiographic, ultrasonographic, and histologic findings. RESULTS: Mean age of dogs was 8.3 years; the most common clinical signs were diarrhea, anorexia, lethargy, vomiting, and weight loss. Abnormal physical examination findings included dehydration, ascites, and signs of pain on palpation of the abdomen. The most notable clinicopathologic findings were low serum ionized calcium concentration and hypoalbuminemia. Abdominal ultrasonography was performed in 12 dogs and revealed intestinal abnormalities in 8 dogs and peritoneal effusion in 7 dogs. Exploratory laparotomy revealed abnormalities in 9 of 16 dogs including thickened small intestine, dilated lacteals, lymphadenopathy, and adhesions. On histologic examination of the small intestine, concurrent inflammation was observed in 15 of 17 dogs, crypt ectasia in 5 of 17, and lipogranulomas in 2 of 17. CONCLUSIONS AND CLINICAL RELEVANCE: Intestinal lymphangiectasia in dogs appears to be a heterogeneous disorder characterized by various degrees of panhypoproteinemia, hypocholesterolemia, lymphocytopenia, and imaging abnormalities. In most dogs, the severity of hypoalbuminemia appears to offer the best correlation with severity of histologic lesions of lymphangiectasia. Imaging abnormalities are common in dogs with intestinal lymphangiectasia but are not specific enough to differentiate this disorder from other gastrointestinal disorders, nor are they predictive of histologic severity.     

Evaluation of the degree and distribution of lymphangiectasia in full-thickness canine small intestinal specimens diagnosed with lymphoplasmacytic enteritis and granulomatous lymphangitis

Intestinal lymphangiectasia (IL) is often observed in dogs with chronic small intestinal diseases. Hypoplasia of the lymphatic vessel due to decreased lymphangiogenesis, which has been suggested in human idiopathic IL, may contribute to the pathogenesis of canine IL. This study aimed to evaluate the diameter and number of lymphatic vessels in full-thickness small intestinal specimens of dogs with IL. Immunohistochemical labeling of lymphatic endothelial cell markers was performed on retrospectively retrieved full-thickness small intestinal specimens. Sixteen dogs with histologically confirmed IL were included, of which 10 had lymphoplasmacytic enteritis (LPE), and six had granulomatous lymphangitis (GL). Nine dogs that died from non-gastrointestinal disorders and with little or no abnormalities in the small intestine were used as controls. Lymphatic vessel diameters in dogs with IL were significantly increased in all layers of the small intestine, including the villus lacteal, lamina propria, submucosa, muscularis, and mesentery, compared with controls (all P<0.01). There was no significant difference in the lymphatic vessel diameters between dogs with LPE and GL (all P>0.05). There was no significant difference in the number of lymphatic vessels between dogs with IL and the controls in all layers of the small intestine (all P>0.05). This study demonstrated that IL was observed in all layers of the small intestine, including the submucosa, muscularis, and mesentery, independent of the underlying disease. Factors other than reduced lymphatic vessels would contribute to the pathogenesis of IL in dogs.     

Clinical characteristics and outcome in dogs with small cell T‐cell intestinal lymphoma

Small cell intestinal lymphoma has not been well characterized in dogs. The objective of this study was to describe clinical characteristics and outcome in dogs with small cell intestinal lymphoma. We hypothesized that affected dogs would have prolonged survival compared with high‐grade gastrointestinal (GI) lymphoma. Pathology records were searched for dogs with histologically confirmed small cell GI lymphoma. Seventeen dogs with confirmed small cell intestinal lymphoma were identified, and clinical and outcome data were retrospectively collected. Histopathology was reviewed by a board‐certified pathologist, and tissue sections were subjected to immunophenotyping and molecular clonality assessment. All dogs had small cell, T‐cell, lymphoma confirmed within various regions of small intestine, with 1 dog also having disease in abdominal lymph nodes. All dogs had clinical signs attributable to GI disease; diarrhoea (n = 13) was most common. Ultrasonographic abnormalities were present in 8 of 13 dogs with abnormal wall layering (n = 7) and hyperechoic mucosal striations (n = 7) representing the most common findings. In total, 14 dogs received some form of treatment. The median survival time (MST) for all dogs was 279 days and the MST for the 14 dogs that received any treatment was 628 days. Dogs with anaemia and weight loss at presentation had significantly shorter survival times and dogs that received a combination of steroids and an alkylating agent had significantly longer survival times. Small cell, T‐cell, intestinal lymphoma is a distinct disease process in dogs, and those undergoing treatment may experience prolonged survival.     

Measurement of intestinal mucosal permeability in dogs with lymphocytic-plasmacytic enteritis

Lymphocytic-plasmacytic enteritis (LPE) is a type of canine inflammatory bowel disease (IBD). One of its most probable causes is a defect in the mucosal permeability barrier. In the present study, intestinal permeability in LPE dogs was examinated to evaluate its clinical value. Twenty-nine dogs with LPE diagnosed by clinical and histological examinations were included in this study. Intestinal permeability was evaluated by measuring the ratio of the concentrations of two sugars (lactulose (L) and rhamnose (R)) with different molecular weights in urine samples after oral administration of a solution containing them. Biopsy specimens of duodenum were evaluated according to histological criteria. The urinary L:R ratio in the 29 LPE dogs (1.68 +/- 1.17, mean +/- SD) was significantly higher than that in the 10 healthy control dogs (0.75 +/- 0.38, P<0.01). In the LPE dogs, a weak correlation was observed between the histopathological grading score of the duodenum and the urinary L:R ratio (r=0.408, P<0.05). The urinary L:R ratio in the 20 dogs showing hypoalbuminemia (< 2.5 g/dl) was significantly higher than that in the 9 dogs with normal serum albumin levels > 2.5 g/dl (P<0.01). In conclusion, permeability of the intestinal mucosa as determined by the urinary L:R ratio could be a useful laboratory parameter for evaluating intestinal damage in LPE dogs.     

Intestinal sclerosis with pseudo-obstruction in three dogs

Intestinal sclerosis causing chronic intestinal pseudo-obstruction was diagnosed in 3 dogs. The pseudo-obstruction was characterized by vomiting and weight loss of 2 weeks' to 3 months' duration. A patent intestinal lumen was determined by contrast radiography and verified at surgery. Intestinal biopsy revealed diffuse atrophy, fibrosis, and mononuclear cell infiltration of the tunica muscularis. Each dog was euthanatized because of a progressive, deteriorating clinical course.     

Chronic diarrhea associated with intestinal anomalies in a six-year-old dog.

A 6-year-old mixed-breed dog was referred because of chronic diarrhea, which had begun after antibiotic treatment for pulmonary disease. Intestinal bacterial overgrowth was presumptively diagnosed on the basis of intestinal mucosal cytologic examination and low serum cobalamin concentration. When the diarrhea did not respond to treatment, contrast radiography was performed and a short small intestine was found. The diarrhea could not be managed by medical treatment, and the dog was euthanatized. Necropsy revealed 2 blind intestinal pouches attached to a 46-cm length of small intestine connecting the stomach and colon. The dog's deteriorating condition was attributable to necrosis and rupture of 1 of the pouches.     

Intestinal neoplasia in horses

BACKGROUND: Intestinal neoplasia of horses is inadequately described. HYPOTHESIS: Intestinal neoplasia of horses has characteristic clinicopathologic features. ANIMALS: Thirty-four horses with intestinal neoplasia. METHODS: Retrospective study. RESULTS: Anamnesis, clinical signs, clinicopathologic and pathologic findings in 34 adult horses diagnosed histologically with intestinal neoplasia were reviewed. The horses ranged in age from 2 to 30 years (mean 16.6 years at presentation). The Arabian breed was most represented and there was no sex predisposition. The most common presenting complaints were weight loss, colic, anorexia, and fever. The most consistent clinical signs were poor body condition, tachycardia, tachypnea, fever, and diarrhea. Useful diagnostic tools included rectal examination, routine blood analyses, abdominocentesis, ultrasonographic examination, rectal biopsy, and exploratory laparotomy. Alimentary lymphoma was the most common intestinal neoplasia identified, followed by adenocarcinoma and smooth muscle tumors. The small intestine was the most common segment of intestine affected for all neoplasms. Intestinal neoplasia was diagnosed antemortem in 13 of 34 (38%) horses. The median time from onset of clinical signs to death or euthanasia was 1.9 months. The discharge rate was 15%. Although the longest survival was observed in horses with jejunal adenocarcinoma, all horses were eventually euthanized because of intestinal neoplasia. CONCLUSIONS: Arabian horses were 4.5 times more likely to have intestinal neoplasia diagnosed than were other breeds.     

Sand impaction of the small intestine in eight dogs

Objective : To describe signalment, clinical findings, imaging and treatment of intestinal sand impaction in the dog. Methods : Medical records of dogs with radiographic evidence of small intestinal sand impaction were reviewed. Results : Sand impaction resulting in small intestinal obstruction was diagnosed in eight dogs. All dogs presented with signs of vomiting. Other clinical signs included anorexia, lethargy and abdominal pain. Radiographs confirmed the presence of radio-opaque material consistent with sand causing distension of the terminal small intestine in all dogs. Four dogs were treated surgically for their impaction and four dogs were managed medically. Seven of the eight dogs survived. Clinical Significance : Both medical and surgical management of intestinal sand impaction in the dog can be effective and both afford a good prognosis for recovery.     

T-cell lymphoma with eosinophilic infiltration involving the intestinal tract in 11 dogs

Among the intestinal tumors of hematopoietic cell origin, lymphoma is the most common in the dog. Herein, we characterized the clinical and pathologic features of 11 dogs (average age, 10.6 +/- 2.5 years) with T-cell lymphoma of the intestinal tract with eosinophil infiltrates. No sex predominance was apparent. All had localized tumor masses in the small intestine. Grossly, the intestinal wall was thickened, and the lumen of the affected intestine was usually narrowed. Microscopically, we observed transmural diffuse invasion of round to pleomorphic tumor cells. Tumor cells showed varying morphology, from scanty to abundant cytoplasm, and round to ovoid nuclei with scattered to dense chromatin. In seven of the dogs, tumor cells had infiltrated into the epithelium. All showed infiltration of eosinophils and all 11 tumors had a T-cell phenotype (CD3+, CD79-). Only one tumor stained positive for the mast cell marker c-kit and none was positive for mast cell tryptase. We did not observe ultrastructurally apparent granules in any of the tumor cells. These results suggest that, in dogs, T-cell lymphomas of intestinal origin resemble mast cell tumors of intestinal origin with respect to cell structure and eosinophil infiltration. Therefore, in the absence of epitheliotropism, it is difficult to confirm the differential diagnosis without immunostaining for mast cell and lymphocyte markers, including mast cell tryptase, c-kit, CD3, and CD79.     

Intestinal permeability testing in dogs with diet-responsive intestinal disease

Fifteen dogs with signs of small and, or, large bowel disease that responded clinically to an exclusion diet were studied, using differential sugar absorption as an objective parameter of the mucosal response to the diet. Intestinal permeability and function were assessed by determining the urinary excretion ratios of lactulose/rhamnose and xylose/3-O-methylglucose, respectively, following oral administration of a mixture of these four sugars. Five dogs, all retrievers, were tentatively diagnosed as having dietary hypersensitivity, based upon resolution of clinical signs and normalisation of high intestinal permeability following an exclusion diet and recurrence of signs (in four of five dogs) upon challenge with the original diet. The fifth dog did not become symptomatic when challenged, but intestinal permeability increased. The remaining 10 dogs were diagnosed as having food intolerance, based upon clinical improvement on an exclusion diet, relapse on challenge with their original diet, but lack of improvement in intestinal permeability. These findings suggest that a differential sugar absorption test may be useful to determine the reasons for clinical response to exclusion diets. Demonstration of increased intestinal permeability with subsequent normalization following an exclusion diet may be useful in the diagnosis of dietary hypersensitivity, while persistent abnormalities in intestinal permeability are suggestive of underlying intestinal disease and food intolerance.     

Bacterial overgrowth associated with a naturally occurring enteropathy in the German shepherd dog

Quantitative and qualitative bacteriological studies were performed on duodenal juice from 19 dogs with chronic small intestinal disease. Bacterial overgrowth was demonstrated in seven German shepherd dogs with minimal histological but specific biochemical abnormalities in the jejunal mucosa. Most frequently this overgrowth comprised bacteria of the normal flora, particularly Escherichia coli and enterococci, but these were occasionally accompanied by bacteria rarely present in the proximal small intestine of the normal dog, particularly Clostridium species. In most cases this overgrowth was associated with raised serum folate and reduced serum vitamin B12 concentrations, a finding consistent with the capacity of many enteric bacteria to synthesise folate and bind vitamin B12.     

A Retrospective Study of Inguinal Hernia in 35 Dogs

Inguinal hernia was associated with trauma in five dogs and was considered nontraumatic in 30 dogs. There were 11 males, 13 intact females, and six spayed females with nontraumatic inguinal hernia. Six dogs had bilateral hernias. Five dogs were younger than 4 months at the time of diagnosis. In 11 older dogs with nontraumatic inguinal hernia, the hernias were identified less than 7 days before surgical repair; in 14 older dogs, the hernias had been recognized for 1 to 60 months. Clinical signs in dogs without small intestinal incarceration were usually limited to a visible or palpable mass without pain or systemic illness. Hemiorrhaphy approaches included inguinal, midline with contralateral ring evaluation, and celiotomy with or without inguinal exposure. Fat and omentum were the most common hernial contents. Small intestine was within the hernias of 12 dogs. Six dogs had nonviable small intestine. Postoperative complications included two incisional infections, one incisional dehiscence, two cases of peritonitis and sepsis associated with bowel leakage after intestinal resection and anastomosis, and one hernia recurrence. The overall prevalence of postoperative complications was 17%, and the mortality rate was 3%. Vomiting for 2 to 6 days was predictive of nonviable small intestine. Dogs younger than 2 years were at 11 times greater risk for nonviable small intestine than dogs older than 2 years. Four of five dogs with nontraumatic inguinal hernia and nonviable small intestine were intact males, whereas none of 13 intact females were affected. Only one of 14 dogs with longstanding hernias had nonviable small intestine.     

Gastroenteritis of basenji dogs

Intestinal digestive and absorptive function and the gross and histologic appearance of the gastrointestinal tract were evaluated in Basenji dogs with chronic diarrhea, asymptomatic Basenji dogs, and healthy control dogs. Gastric rugal hypertrophy, lymphocytic gastritis, and gastric mucosal atrophy occurred in asymptomatic and affected Basenji dogs. All affected dogs had moderate or severe intestinal lesions characterized by villous clubbing and fusion, increased tortuosity of intestinal crypts, and diffuse infiltration of mononuclear inflammatory cells. Intestinal lesions in asymptomatic Basenji dogs invariably were less severe than those in affected dogs, but the small intestinal lamina propria of asymptomatic Basenji dogs consistently contained greater numbers of mononuclear inflammatory cells than did that of control dogs. The proportion of cells containing each immunoglobulin isotype (IgG, IgM, IgA) was similar among affected Basenji dogs, asymptomatic Basenji dogs, and control dogs. As compared to healthy beagle controls, intestinal function was abnormal in both affected and asymptomatic Basenji dogs evaluated by combined N-benzoyl-L-tyrosyl-p-aminobenzoic acid and d-xylose test, but malabsorption and maldigestion were most pronounced in affected Basenji dogs.     

Increased expression of fractalkine and its receptor CX(3)CR1 in canine inflammatory bowel disease and their possible role in recruitment of intraepithelial lymphocytes

The interaction between fractalkine/CX(3)CL1 and its receptor CX(3)CR1 has been reported to play an important role in various human inflammatory diseases, including inflammatory bowel disease (IBD) mediated by lymphocyte chemoattraction. The objective of this study was to investigate the role of fractalkine and CX(3)CR1 in lymphocyte migration in canine IBD. IBD was diagnosed in 34 dogs, and 19 healthy beagles were used as normal controls. We quantified intestinal mRNA and protein expression of fractalkine and CX(3)CR1 by real-time RT-PCR and ELISA, respectively, and examined the localization of fractalkine in canine intestine by immunohistochemistry. The expression of CX(3)CR1 and surface antigens on peripheral blood mononuclear cells (PBMCs) and intraepithelial lymphocytes (IELs) was analyzed by flow cytometry. Intestinal fractalkine and CX(3)CR1 mRNA was significantly up-regulated in IBD dogs compared with the healthy control dogs. In addition, fractalkine expression on intestinal epithelial cells was significantly increased in the intestinal mucosa of IBD dogs compared with the healthy dogs. CX(3)CR1(+) PBMCs were significantly elevated in IBD dogs and positively correlated with the histopathological severity of IELs infiltration. These CX(3)CR1(+) PBMCs predominantly expressed markers for cytotoxic T cells. Almost all IELs expressed CD3, and the majority of cells expressed CD8 rather than CD4, which was analogous to the CX(3)CR1(+) PBMCs. These results suggest that the fractalkine-CX(3)CR1 interaction may contribute to the pathogenesis of canine IBD through migration of IELs.     

Small intestinal ganglioneuromatosis in a dog

A 6-week-old Staffordshire Bull Terrier cross was presented with a 4-week history of vomiting and small bowel diarrhoea. Abdominal ultrasound showed thickening of the distal jejunum and ileum. The dog underwent two exploratory laparotomies, during which grossly abnormal sections of intestine were resected. The patient developed septic peritonitis 48 h after the second surgery, caused by dehiscence of an intestinal anastomosis, and was euthanased. All intestinal tissue samples were examined histopathologically and a diagnosis of gastrointestinal ganglioneuromatosis was made. Intestinal ganglioneuromatosis is rare and this case represents a novel occurrence in the small intestine of a dog.     

Protein-losing enteropathy in a dog with lymphangiectasia,lymphoplasmacytic enteritis and pancreatic exocrine insufficiency

This is a report of seven-year-old male Akita mixed dog, with protein-losing enteropathy (PLE). He had a history of chronic vomiting and diarrhea with anorexia/hyporexia. Previously he suffered acute abdomen about eight months prior to this visit. Our dog showed uncommon combination of diseases that could cause PLE since it was affected by inflammatory bowel disease (IBD), intestinal lymphangiectasia (IL), and exocrine pancreatic insufficiency (EPI). The dog had most of the abnormalities found in IL, as well as hypoalbuminemia, hyperglobulinemia, lymphopenia, hypocalcemia, and hypercholesterolemia. During endoscopy exam, we found changes characteristic of IL such as irregular small white spots. We took biopsies from stomach, duodenum, and cecum. These biopsies showed infiltration by lymphocytes and plasmatic cells in the lamina propria also, the duodenal biopsies showed moderate dilation of the lymphatic vessels. The patient had 2.1?µg/mL of TLI, this result was compatible with EPI. We assume that the first pathology in this animal was IBD, which caused chronic pancreatitis (CP) that in turn progressed to EPI. It is also possible that IL was secondary to IBD. We have reported for the first time the correlation of IBD and EPI in dogs. This should change our approach to treating chronic diarrhea in dogs. Therefore, we propose that dogs diagnosed with EPI should also be subjected to endoscopy and intestinal biopsy. Similarly, to rule out secondary EPI, TLI should be measured routinely in dogs with IBD.     

Volvulus of the colon in four dogs

Four dogs were examined because of vomiting of 7 to 48 hours' duration. Gas-distended segments of intestine were identified radiographically in all dogs, but the affected portion of the intestinal tract could not always be identified as the colon. Volvulus of the colon was diagnosed during surgery in all 4 dogs. Gastrocolopexy was performed following derotation of the colon in 3 of the dogs. In 1 dog, a colectomy and an ileorectal anastomosis were performed. All 4 dogs survived. Volvulus of the colon should be considered as a cause of vomiting of short duration in dogs for which there is radiographic evidence of intestinal dilatation.     

Association between intestinal lymphangiectasia and expression of inducible nitric oxide synthase in dogs with lymphoplasmacytic enteritis

Intestinal lymphangiectasia (IL) is a common complication in dogs. Since nitric oxide (NO) is known to relax the lymphatic vessel, we evaluated inducible NO synthase (iNOS) expression using immunohistochemistry in 13 dogs with lymphoplasmacytic enteritis (LPE) with or without IL. The duodenal iNOS expressing cells were significantly increased in dogs with IL-negative or IL-positive LPE dogs (P=0.025, P=0.007) compared with control dogs. However, there was no significant difference in iNOS expression between IL-positive and IL-negative tissues. Based on these results, there is no clear evidence for the NO overproduction in the pathogenesis of IL in dogs with LPE. Factors other than NO could, thus, contribute to IL in dogs with LPE.     

小动物肠道异物性梗阻和出血性胃肠炎诊治的比较研究

小动物肠道异物引起犬肠道梗阻是犬常见肠道疾病之一。在临床上容易和出血性胃肠炎发生混淆。本试验通过一例患犬的病史,结合血常规检查、CRP检查、内窥镜检查,并与出血性胃肠炎鉴别诊断,确定为犬肠道异物性梗阻,并对患犬尝试使用剖腹探查术治疗,术后以消炎、补充营养和体液、修复胃肠道粘膜为主,取得明显的治疗效果。研究结果可为宠物犬肠道异物性梗阻和出血性胃肠炎的鉴别诊治提供可参考的诊治方案。     

Gastric and intestinal surgery.

Gastric surgery is commonly performed to remove foreign bodies and correct gastric dilatation-volvulus and is less commonly performed to treat gastric ulceration or erosion, neoplasia, and benign gastric outflow obstruction. Intestinal surgery, although commonly performed by veterinarians, should never be considered routine. The most common procedures of the small intestinal tract performed in dogs and cats include enterotomy and resection/anastomosis. Surgery of the large intestine is indicated for lesions causing obstruction, perforations, colonic inertia, or chronic inflammation.