Ileocolic junction resection in dogs and cats: 18 cases.

There is limited veterinary literature about dogs or cats with ileocolic junction resection and its long-term follow-up. To evaluate the long-term outcome in a cohort of dogs and cats that underwent resection of the ileocolic junction without extensive (≥50%) small or large bowel resection. Medical records of dogs and cats that had the ileocolic junction resected were reviewed. Follow-up information was obtained either by telephone interview or e-mail correspondence with the referring veterinary surgeons. Nine dogs and nine cats were included. The most common cause of ileocolic junction resection was intussusception in dogs (5/9) and neoplasia in cats (6/9). Two dogs with ileocolic junction lymphoma died postoperatively. Only 2 of 15 animals, for which long-term follow-up information was available, had soft stools. However, three dogs with suspected chronic enteropathy required long-term treatment with hypoallergenic diets alone or in combination with medical treatment to avoid the development of diarrhoea. Four of 6 cats with ileocolic junction neoplasia were euthanised as a consequence of progressive disease. Dogs and cats undergoing ileocolic junction resection and surviving the perioperative period may have a good long-term outcome with mild or absent clinical signs but long-term medical management may be required.

Ileal ganglioneuromatosis in a piglet: histopathological and immunohistochemical studies.

Ganglioneuromatosis (GNM) is a rare condition characterized by the benign proliferation of ganglion cells, nerve fibres and supporting cells of the enteric nervous system. Necropsy examination of a female piglet weighing 4 kg revealed a well-demarcated 20 cm segment of terminal ileum with thickening of the wall. Microscopically, the lamina propria was infiltrated by enteric glial cells and large ganglion cells. Within the submucosal and muscular layers, aggregates of neurons were interlaced by Schwann cells and enteric glial cells arranged in concentric rings. Immunohistochemically, the neurons were weakly labelled for S-100 and neuron-specific enolase, Schwann cells expressed S-100 and vimentin and enteric glial cells expressed glial fibrillary acidic protein and S-100. Pathological and immunohistochemical findings supported the diagnosis of ileal GNM.

Transmural ileal ganglioneuromatosis in a young Boer goat (Capra hircus).

A diagnosis of transmural ileal ganglioneuromatosis was made in a 15-day-old goat that was found dead following a period of diarrhoea and inappetence. Grossly, the entire length of the wall of the ileum was pale and firm with a variably segmental to transmural thickening. Microscopically, the ileal transmural thickening was due to a diffuse proliferation of both ganglionic and glial cells forming cell nests or packets that infiltrated the wall and into the mesentery surrounding a mesenteric lymph node. The neoplastic ganglionic cells were immunoreactive for S100, synaptophysin and triple neurofilament, while the glial spindle cells were immunoreactive with glial fibrillary acidic protein, S100 and laminin confirming their Schwann cell identity. Nerve fibres expressing neurofilament protein 200 and phosphorylated neurofilament (SMI-31) were observed rarely. Ganglioneuromatosis is defined as diffuse exuberant proliferation of all components of the intestinal ganglionic plexuses. In man, the transmural form has more grave clinical consequences than a focal pattern and is commonly associated with germline mutations in the RET proto-oncogene. Whether there is any comparable molecular genetic abnormality in animals remains unknown; however, ganglioneuromatosis needs to be included in the differential diagnosis of tumours of the autonomic enteric nervous system.

Spontaneously arising concurrent ileocaecal adenocarcinoma and renal pelvis transitional cell carcinoma in a rhesus macaque (Macaca mulatta).

A 25-year-old, female rhesus macaque (Macaca mulatta) presented with a history of weight loss despite a normal appetite and supportive care. The animal was humanely destroyed due to poor prognosis. Post-mortem examination revealed a focally extensive, firm, white annular constriction at the ileocaecal junction and an incidental finding of a pale white nodule approximately 0.8 cm in diameter in the left renal pelvis. Based on the microscopical findings, ileocaecal adenocarcinoma and renal pelvis transitional cell carcinoma (TCC) were diagnosed. The use of cytokeratin (CK)-7 and -20 and uroplakin III as potential renal TCC markers was evaluated. The neoplastic cells were labelled intensely with antibodies to uroplakin III, but not to CK-7 or -20. Spontaneous intestinal adenocarcinoma has been documented in the rhesus macaque, but concurrent renal pelvis TCC is highly unusual.

Hemangioma of the ileum in a dog.

An 11-year-old, castrated male beagle dog was presented with a sudden onset of clinical signs of depression, abdominal discomfort, anorexia and melena. Radiography and ultrasonography revealed a well-circumscribed mass lesion with a size of 5 cm in diameter at the hypogastrium. A complete blood count and blood chemistry revealed severe anemia, hypoproteinemia and hypoalbuminemia. Through celiotomy, a large tumor mass involving the ileum was resected. The inside of the mass was irregular and sponge-like structure with multiple cavitated structures. On histology, the lesion was diagnosed to be hemangioma of the ileal wall. To the best of our knowledge, this unusual case is the first clinical report on the ileal hemangioma in non-human animal species.

A KIT-positive gastrointestinal stromal tumor in a ferret (Mustela putorius furo).

A 1.5-year-old, neutered, male ferret (Mustela putorius furo) was presented with sudden lethargy, anorexia, and diarrhea. Clinical and radiographic examinations revealed an intra-abdominal mass. An explorative laparotomy was performed. A neoplasm, located in the ileum wall, was submitted for histopathologic examination. The tumor consisted of weakly eosinophilic spindle cells arranged in a compact pattern with haphazardly interlacing bundles. Neoplastic cells labeled positively for KIT (cluster of differentiation 117, stem cell factor receptor) and vimentin. Based on histologic and immunohistologic results, this tumor was diagnosed as a gastrointestinal stromal tumor. Results suggest that this ferret tumor shares strong similarities with the canine and human counterparts.

Mesojejunoileac liposarcoma with intrahepatic metastasis in a dog.

We report a liposarcoma at the mesojejunoileum that was widely excised, and then the intrahepatic metastatic liposarcoma was found. The dog was treated by two single-agent chemotherapy separately. The patient was an 8-year-old, male Dachshund, and was referred to our hospital owing to the significant distention of the left abdomen. Neither radiography nor ultrasonography detected the actual association of the tumor with the abdominal viscera before surgery. A large-sized tumor mass that adhered to the mesojejunoileum was explored by laparatomy. Final diagnosis of a pleomorphic liposarcoma was made by the routine histology and further identified by Oil Red O stain. The two single-agent chemotherapy including doxorubicin followed by capecitabine, however, failed to cause remission of the intrahepatic metastatic lesions. The patient died 22 months after operation and the cause of death was supposed to be metastatic liposarcoma.

Equine histoplasmosis presenting as a tumor in the abdominal cavity.

A 3.5-year-old Thoroughbred mare presented at necropsy with a large mass at the root of the mesentery and multiple smaller mesenteric masses. The mucosa of the small intestine contained numerous raised nodules. Histologic examination revealed severe granulomatous mesenteric lymphadenitis and enteritis. Epithelioid macrophages and multinucleated giant cells frequently contained numerous intracytoplasmic yeast organisms, which were strongly positive on immunohistochemical staining when using a polyclonal antibody against Histoplasma spp. A diagnosis of abdominal histoplasmosis was made based on the gross, microscopic, and immunohistochemical findings.

Canine extracutaneous mast-cell tumours consisting of connective tissue mast cells.

Two cases of canine extracutaneous mast-cell tumours were encountered, originating from the mucosa of either the oral cavity or the small intestine. The dogs had no neoplasms in the skin. Immunohistochemical and ultrastructural studies demonstrated that the neoplastic cells had the features of connective tissue mast cells. It would seem, therefore, that at least some extracutaneous forms of the neoplasm originate from connective tissue mast cells. Heparin was a useful cytological marker to diagnose this type of mast-cell tumour.

Small intestinal adenomatous polyposis resulting in protein-losing enteropathy in a horse.

A 4-year-old Quarter Horse gelding was presented with a history of weight loss of 6 months duration, along with extensive ventral subcutaneous edema. Clinicopathologic findings included a markedly low serum total protein (2.9 g/dl) and a low packed cell volume (24%). The mucosal surface of the distal jejunum and entire ileum were carpeted with numerous polypoid, papillary, and glandular masses comprised of pseudostratified tall columnar cells and large numbers of interspersed goblet cells. Neoplastic change was diffuse throughout the mucosa of each mass, but abrupt demarcation occurred between neoplastic masses and adjacent mucosa. Immunohistochemical staining for protein of the p53 tumor suppressor gene revealed only occasional cytoplasmic reactivity within polyps and normal mucosa. Nuclear staining for papillomavirus antigens was not observed. Electron microscopic examination revealed features of well-differentiated intestinal epithelial cells, including apical tight junctions and microvilli, desmosomes, and the presence of numerous goblet cells. Microorganisms were not detected. Small intestinal polyposis should be considered as a rare differential diagnosis for protein-losing enteropathy in the horse.

Rectal prolapse of an ileocaecal neoplasm associated with intussusception in a cat.

Intussusception associated with lymphoma of the ileocaecocolic junction was diagnosed in a 12-year-old female domestic short-haired cat that presented with a 3-week history of diarrhoea and a protruding anal mass. Surgical exploration revealed an ileocolonic intussusception proximal to the mass at the ileocaecal junction which was excised. A diagnosis of ileocaecocolic lymphosarcoma was made and euthanasia was later performed. This is an unusual case of an ileocaecal junction tumour that manifested as a rectal prolapse associated with intussusception in a cat.

Multiple peripheral nerve sheath tumors in the small intestine of a horse.

Multiple neurofibromas, schwannomas, and hyperplastic enteric plexuses were observed in the distal jejunum and ileum of a 6-year-old pinto gelding. The animal was presented because of an acute episode of colic. Three meters of distal small intestine, partially incarcerated in the epiploic foramen, were surgically removed. Numerous tumor nodules up to 10 mm in diameter were found adjacent to a Meckel's diverticulum, predominantly located in the subserosa of a hypertrophic segment. Histologically, tumors were well demarcated and composed of interlacing fascicles formed by spindloid cells. Adjacent enteric plexuses were hyperplastic. Immunohistochemically, all tumors were positive for vimentin and S-100. Desmin immunoreactivity was only observed in larger tumors (> 500 microns). Glial fibrillary acid protein was demonstrated nearly exclusively in smaller ones. Immunostaining for neurofilament was restricted to entrapped ganglion cells. Based on conventional light microscopic examination and immunohistochemical evaluation, the lesion was diagnosed as multiple benign peripheral nerve sheath tumors in the small intestine.

Clinical evaluation of in-feed zinc bacitracin for the control of porcine intestinal adenomatosis in growing/fattening pigs.

This field trial was designed to investigate whether the incorporation of zinc bacitracin into pig feed would prevent porcine intestinal adenomatosis. Two hundred-and-eighty-eight weaned pigs on a farm with a previous history of the disease were divided into 16 pens of 18 pigs. Two dietary regimens of zinc bacitracin were tested: from weaning up to 100 days of age, either 300 or 200 ppm zinc bacitracin were incorporated; from 100 to 125 days of age, either 200 or 100 ppm zinc bacitracin were added; and from 125 to 156 days of age (slaughter), either 100 or 50 ppm zinc bacitracin were added. The results were compared with a positive control group which received 60, 60 and 30 ppm salinomycin during the same periods, and with a negative control group which received no antibacterial and/or performance enhancer. The mortality, diarrhoea scores, average daily weight gains, average daily feed intakes and feed conversion ratios of the pigs were assessed. At slaughter, samples of ileum were taken from eight randomly selected pigs per group for bacteriological and histopathological examinations. The three treated groups all performed better than the control group, and the group receiving the high dose regimen of zinc bacitracin performed significantly better than the groups receiving the low dose of zinc bacitracin or salinomycin.

Ileal lymphoma in swine.

Eleven cases of alimentary lymphoma affecting the ileum were observed among 26 cases of swine lymphoma detected by meat inspection in Kochi, Japan. The ileal lymphomas were located in the Peyer's patches, along with early involvement of regional lymph nodes, and showed a characteristic pattern of follicular invasion leading to diffuse growth. Following the National Cancer Institute Working Formulation, 10 neoplasms were classified as diffuse, large, noncleaved cell lymphomas and one neoplasm was a diffuse, mixed, small to large cell lymphoma. Both types of lymphoma featured numerous intermingled "starry sky" histiocytes. The lymphoma cells tended to infiltrate into the muscular layer of the ileum in an "Indian file" pattern. Two cases also showed transserosal metastasis into the abdomen and leukemic change. The lymphoma cells showed membrane positivity for alkaline phosphatase and diffuse cytoplasmic staining for acid phosphatase and non-specific esterase. Monoclonal intracytoplasmic immunoglobulins were demonstrated in nine neoplasms (IgM-lambda in seven, IgG-lambda in one, and IgG-kappa in one). In the areas of follicular invasion, an attenuated network of follicular dendritic cells was visualized via an antiserum against the beta subunit of S-100 protein. Ultrastructurally, strands of dilatated rough endoplasmic reticulum and scattered or clustered dense bodies were noted. When compared with feline and human alimentary lymphoma, including Burkitt's lymphoma, the present neoplasms possessed distinctive features, such as originating in Peyer's patches, transserosal metastasis, and predominantly large B cell type with IgM-lambda type immunoglobulin expression, although some features were similar.

Spontaneous metastasizing mucinous adenocarcinoma in the ileum of a Sprague-Dawley rat.

Spontaneous tumours of the rat small intestine are extremely rare. A control Sprague-Dawley male rat from a carcinogenicity bioassay had a mucinous adenocarcinoma in the ileum. Tumour metastasis was observed in the mesenteric lymph node, lung, and seminal vesicles. Gross and histopathological features of this neoplasm are described and discussed.

Globule leukocyte tumor involving the small intestine in a cat.

Globule leukocyte tumor involving the distal portion of the jejunum and proximal portion of the ileum caused chronic vomiting and weight loss in a 3-year-old cat. The intestinal mass was resected during exploratory laparotomy. The histologic appearance of the mass was characterized by inclusion of numerous intracytoplasmic eosinophilic granules. Similar cells were found in the mesenteric lymph node and were suggestive of metastasis. Tumor recurrence was not detected until 13.5 months after the surgery. The malignant but slow-growing nature of this tumor allowed a disease-free interval that exceeded 1 year, despite incomplete tumor resection.

Intestinal adenocarcinoma of the ileocecal junction in a chicken.

An 89-week-old male chicken was presented with signs of depression, emaciation, and weakness. At necropsy, a stricture was found at the ileocecal junction that resulted in blockage and dilation of the ileum proximal to the stricture. Histologically, neoplastic epithelial cells that contained mucin had invaded the intestinal wall and produced a fibrous connective tissue reaction. The lesion was diagnosed as scirrhous intestinal adenocarcinoma.

Electron microscopy of intestinal adenomatosis in the blue fox, Alopex lagopus.

Scanning electron microscopy of adenomatous intestinal tissue in the blue fox revealed an irregular surface topography of the colon with increased diameter of the crypt openings and prominent ridge formations between crypts. The ileum showed villous atrophy and fusion. Microvilli were short and irregular. Small ulcerations of intestinal mucosa were seen. Freeze-fracture revealed curved intracellular organisms in the altered epithelial cells. Transmission electron microscopy showed features associated with immaturity and high protein synthesis. Filamentous extensions from the basolateral plasma membrane of altered epithelial cells sometimes penetrated the basal lamina. The cytoplasm contained numerous polyribosomes, nuclei had many indentations and large and irregular nucleoli. Intracellular bacteria, with morphology corresponding to Campylobacter spp. were found in the apical epithelial cytoplasm. No host-cell-derived membrane was seen to surround the bacteria.

Morphology and immunoperoxidase studies of intestinal adenomatosis in the blue fox, Alopex lagopus.

In a blue fox farm about 300 of 400 weanling pups were affected with diarrhoea and prolapse of the rectum. About 40 pups died in an emaciated state after a few days of disease. Eight pups were submitted for examination. Pathological findings were restricted to the caecum, proximal colon and rectum, with occasional extension to the ileum. Affected areas revealed a thick and rigid intestinal wall, a narrow lumen and a thickened, wrinkled and sometimes ulcerated mucosa. Histologically, the mucosa showed long tortuous crypts outlined by a high pseudostratified epithelium which lacked goblet cells. Epithelial cells revealed increased basophilia, and mitoses were seen along the entire crypt length and in the surface epithelium. Silver impregnation showed curved organisms in the apical cytoplasm of the altered epithelial cells. Penetration of the muscularis mucosa by the altered epithelial cells was frequent. The avidin-biotin-immunoperoxidase complex (ABC) technique revealed positive organisms in the apical cytoplasm of altered epithelial cells, when rabbit antisera against different biotypes and serotypes of Campylobacter jejuni and Campylobacter coli were used. Antisera against Campylobacter sputorum subsp. muscosalis and Campylobacter hyointestinalis were negative.

Heterotopic gastric mucosa of the small intestine in laboratory beagle dogs.

Out of the 365 young laboratory beagle dogs which were used in 17 toxicity bioassays, 15 cases (4.1%) were diagnosed as having congenital heterotopic gastric mucosa of the small intestine. Its incidence in the male dogs (12 cases out of 187) was higher than in the female dogs (3 cases out of 178). Grossly, the lesions were seen as an ulcerous focus of the small intestine, 25 cm to 88 cm proximal to the ileocecal valve. All of the lesions were quite similar histologically and electron microscopically to the normal gastric mucosa, which are composed of the surface mucous cells, chief cells, parietal cells, mucous neck cells and basal granulated cells of the stomach. And consequently, they were considered to be that of a congenital heterotopic tissue in the small intestine. The only morphological characteristic of these lesions different from the regular gastric mucosa was an association with the tubular structure seen in the basal region of these mucosal layers. These cells were considered to be of mucous-secreting cell origin because of secreting type III mucous evident from paradoxical concanavalin A or periodic acid Schiff stains. They seemed to be protecting the surrounding intestinal mucosa from gastric acid.