Prevalence and risk factors associated with outcome of surgical removal of pedunculated lipomas in horses: 102 cases (1987-2002)

OBJECTIVE: To determine the prevalence of pedunculated lipomas and identify risk factors affecting postoperative complications and survival in horses at a veterinary teaching hospital undergoing surgery for colic caused by pedunculated lipomas. DESIGN: Retrospective study. ANIMALS: 102 horses with a diagnosis of pedunculated lipoma. PROCEDURE: Age, breed, weight, and sex of horses with pedunculated lipomas were compared with the total equine hospital population and the population of horses admitted for abdominal surgery during the same period. Follow-up information was obtained by reevaluation or contact with owners via telephone or written request. RESULTS: Prevalence of pedunculated lipomas as a reason for abdominal surgery in horses, compared with the population of horses with and without lipomas admitted for abdominal surgery, was 10%. Castrated male Saddlebred and Arabian horses > 14 years old were identified as being at risk for developing pedunculated lipomas. Postoperative complications were detected in 72% of horses with pedunculated lipomas. Variables associated with low survival rates included surgery before 1992, heart rate > 80 beats/min, abnormal color of abdominal fluid, pale mucous membranes, surgery requiring intestinal resection, and inability to attain a mean arterial pressure > or = 100 mm Hg. Horses undergoing surgery from 1992 to 1996, weighing < 409 kg (900 lb), or requiring jejunojejunal anastomosis had a high survival rate. CONCLUSIONS AND CLINICAL RELEVANCE: Although many of the variables reflected the health of the horse at the time of surgery, results may help veterinarians recognize risk factors associated with development of pedunculated lipomas and better predict the outcome of horses undergoing surgery for colic caused by pedunculated lipomas.     

Multiple inflammatory gastric polyps treated by endoscopic polypectomy with argon plasma coagulation in a dog

An 11‐year‐old spayed female miniature dachshund was evaluated for a 2‐month history of chronic vomiting. Abdominal ultrasonography revealed a heterogeneous mass in the pyloric region. Contrast upper gastrointestinal radiography demonstrated impairment of gastric outflow. Endoscopic examination revealed multiple polyps at the gastric pylorus. The pyloric polyps were variable in size, sessile‐shaped and pedunculated. Initially, endoscopic polypectomy was attempted, but all the polyps could not be completely resected. Thus, endoscopic polypectomy with argon plasma coagulation was performed to cauterise the lesions. The histopathological diagnosis of the lesions was inflammatory polyps, and a moderate number of Helicobacter spp. was revealed. After the argon plasma coagulation treatment, the dog did not vomit, and improvement of clinical signs was maintained for 13 months. Endoscopic polypectomy with argon plasma coagulation may be useful for mixtures of sessile and pedunculated polyps. The present report may provide a basis for further studies of argon plasma coagulation treatment for canine gastrointestinal polyps.     

Lingual osteoma in a dog

An 11-year-old male Belgian shepherd dog was evaluated for a one-week history of progressive lethargy, decreased appetite and excessive panting. On physical examination, a pedunculated mass protruding from the right side of the tongue base was observed. The mass was solid, irregular and multi-lobulated, and it measured approximately 4×2 cm. The mass was surgically excised. The histological examination was consistent with a lingual osteoma and the margins were free of neoplastic cells. The dog was euthanased eight months after the diagnosis because of an unrelated problem and no evidence of recurrence at the surgical site was appreciated at that time. To the author's knowledge, this is the first report of a lingual osteoma in a dog, and, therefore, it should be included in the differential diagnosis of masses on the tongue, especially pedunculated masses located at the base of the tongue.     

Polypoid cystitis as a cause of haematuria in a pony mare

A 15-year-old pony mare was presented for investigation of haematuria of 2 weeks' duration. On cystoscopy, multiple small pedunculated soft tissue structures were observed on the bladder mucosa. Histopathological analysis of the masses was consistent with chronic polypoid cystitis. The polypoid lesions and associated haematuria resolved following prolonged antibiotic treatment. Polypoid cystitis has not previously been described in horses. This condition should be considered a differential for haematuria, requiring cystoscopy and biopsy to confirm a diagnosis.     

Malignant seminoma in a cryptorchid stallion

A 16-year-old cryptorchid Quarter House with colic had a large, lobulated soft-tissue mass to the left of the pelvic inlet. At surgery, 2 large multilobulated pedunculated masses were removed. A large blood vessel enveloped by one of the masses was damaged, and the horse exsanguinated. Postmortem examination of the abdomen revealed the masses to be malignant seminoma, with multiple sites of metastasis.     

Microscopic anatomy of the oesophagus in the southern white-breasted hedgehog (Erinaceus concolor) a histochemical,stereological, and scanning electron microscope study

The present work was designed to investigate the microscopic structure of the oesophagus in the southern white-breasted hedgehog (Erinaceus concolor) using histochemical staining, Scanning electron microscope (SEM), and stereological procedures. Four adult males were included in our study. Serial sections of the entire length of the oesophagus were stained with aldehyde fuchsin, alcian blue (pH 2.5), Periodic acid Schiff (PAS), and Masson's trichrome. Then, the total volume of the oesophagus, and the total volume of its different layers, were estimated using Cavalieri's principle. The oesophageal epithelium was a non-keratinized stratified squamous type. Muscularis mucosa was present as a thick layer between lamina propria and submucosa and its thickness was increased toward the stomach. Tunica submucosa was a loose connective tissue containing an oesophageal gland with PAS-positive and AB-positive reactions throughout the submucosa and become denser toward the stomach. The tunica muscularis consisted of two distinct striated muscle layers, and its thickness was decreased toward the stomach. On SEM images, the cervical and thoracic oesophagus showed shallow folding, while the abdominal part had deeper folds. The present findings indicate that the histological properties of the oesophagus in southern white-breasted hedgehogs have slight similarities with rodents and considering its epithelium, submucosal glands and tunica muscularis more resemble with dog oesophagus. The obtained results may be quite helpful to improve the current knowledge of the histophysiology of the hedgehog gastrointestinal tract as a member of eulipotyplan mammals and as a pet for biologists and veterinarians.     

Gastritis and gastric perforation due to Habronema spp. in the horse

A three-year-old horse was admitted to the Tehran Veterinary faculty teaching hospital with colic symptoms. The horse died with severe pain after two hours. Necropsy findings revealed a heavy worm infestation in the stomach. Parasitological examinations identified massive in vasion of Habronema muscae on the stomach mucosal surface and Draschia megastoma in the deep layer of mucosa and muscles.Histopathological sections showed two separate lesions including diffuse infiltration of mononuclear inflammatory cells with a number of eosinophils in the mucosa and submucosa that suggested eosinophilic gastritis. Another finding was a large granulation mass in the deep layer of the submucosa that contained granulomatous necrotic tissue and cross sections of D. megastoma.     

Use of porcine small intestinal submucosa for corneal reconstruction in dogs and cats: 106 cases

Objectives : To describe the efficacy of porcine small intestinal submucosa in corneal reconstructive surgery in dogs and cats through a large retrospective study. Methods : A retrospective evaluation of 106 cases of surgical reconstruction of the cornea with small intestinal submucosa seen between May 2005 and January 2010 was carried out. The corneal defect was filled by microsurgical grafting of porcine small intestinal submucosa. The biomaterial implant was deposited in one or several layers depending on the depth of the defect. The animals were examined 3, 6 and 12 weeks after surgery. Results : Vision was preserved in all eyes at three months post‐surgery. In 74 cases (69.8%) the corneal scar was either transparent or discrete, whilst in 32 cases (30.2%) a mild or marked scar was observed. Minor complications occurred in 9 cases (8.5%) with partial integration of the small intestinal submucosa and in 24 cases (22.6%) with faint or mild corneal pigmentation, without impairing vision. In cases followed over a period longer than three months, major complications occurred in five dogs resulting in vision impairment because of pronounced pigmentation. Clinical Significance : Corneal grafting of porcine small intestinal submucosa is an effective method for corneal reconstruction resulting in corneal transparency in most cases. It is an excellent alternative to conventional conjunctival grafts.     

Severe gastric impaction secondary to a gastric polyp in a horse

A 13-year-old Percheron gelding was presented for refractory gastric impaction. At necropsy a pedunculated 10 cm × 11 cm × 14 cm mass, histologically identified as an inflammatory polyp, was suspected to have been partly obstructing the pylorus. This is the first report of a polyp resulting in gastric outflow obstruction in a horse.     

Colitis associated with Clostridium difficile in specific-pathogen-free C3H-scid mice

Soft feces and a decreased delivery rate were observed in a specific-pathogen-free (SPF) C3H-scid mouse breeding colony. Grossly, the ceca were shrunken and edematous in the affected mice. Histopathologically, severe edema in the cecal submucosa as well as infiltration of inflammatory cells in the lamina propria and submucosa of the ceca and colon were observed. No pathogenic microorganisms were detected by the routine microbiological tests. By anaerobic bacterial-examination, Clostridium (C.) difficile with toxin A was isolated from the cecal contents of the affected mice. The mice were diagnosed with C. difficile-associated colitis. This case appears to be the first report of natural infection with C. difficile in SPF mice with clinical signs.     

Necrotizing typhlocolitis associated with a spirochete in rheas (Rhea americana).

Necrotizing typhlocolitis was diagnosed in 13 juvenile common rheas (Rhea americana) from three separate of geographically isolated Ohio flocks, with mortality ranging from 25% to 80%. At postmortem examination, a diphtheritic membrane covered ulcerated cecal mucosa. Histologically, cecal sections showed necrosis and granulomatous-to-suppurative inflammation that extended into the submucosa and often surrounded large eosinophilic colonies of bacteria. Warthin-Starry staining showed these colonies to be composed of entangled spirochetes that invaded the submucosa and frequently were present transmurally. Similar organisms were identified by Warthin-Starry staining in the cecum of a juvenile rhea from a fourth flock that histologically had mild lymphocytic typhlitis. Scanning and transmission electron microscopy demonstrated the presence of a spirochete in the ceca. Anaerobic culture yielded a gram-negative, beta-hemolytic spirochete. Coccidia, histomonads, and Salmonella spp. were consistently absent.     

Intestinal polyps in a lamb

Eight pedunculated jejunal polyps 4–13mm in diameter were found in a 3 to 5-month-old lamb during routine meat inspection at an export slaughterhouse in Canterbury. Histological examination revealed papilliform growths consisting of hyperplastic villi with numerous developmental stages of coccidia-like organisms in the epithelial cells of the polyps' mucosa. It is suggested that this specimen represents an uncommon manifestation of chronic ovine coccidiosis.     

Ureteral fibroepithelial polyp in an owl monkey (Aotus nancymae)

Ureteral fibroepithelial polyps are benign mesodermal tumors in humans that occur predominantly in the proximal ureter. During a routine necropsy of a wild-caught, research na?ve, adult, male, Aotus nancymae, the left ureter just distal to the renal pelvis contained a pedunculated, lobulated neoplasm with a narrow stalk at the base projecting into the lumen. The left renal pelvis was found to be mildly dilated. The histologic characteristics of the ureteral mass were consistent with a fibroepithelial polyp. To our knowledge, this is the first report describing a ureteral fibroepithelial polyp in a nonhuman primate.     

Colorectal adenocarcinoma in dogs: 78 cases (1973-1984)

Colorectal adenocarcinoma was diagnosed in 78 dogs. Clinical signs in all 78 dogs included tenesmus, hematochezia, and dyschezia; most of the dogs had clinical signs less than or equal to 12 weeks before examination. Ultimately, most dogs were euthanatized because of the severity of clinical signs. Proctoscopy and colonoscopy were essential for complete assessment of extent of disease. Tumors were classified by gross appearance and included single, pedunculated masses, 2 or more nodular masses, and annular or intraluminal masses. In dogs in which survival time was compared with location and gross appearance of the tumor, dogs with annular masses had the shortest mean survival time (1.6 months), and dogs with single, pedunculated, polypoid tumors had the longest mean survival time (32 months). The rectum was a more common site than the colon, with 48.2% of the tumors developing in the middle portion of the rectum. Six different modes of surgical treatment were used, depending on the location and type of mass. Dogs that did not have surgical treatment had a mean survival time of 15 months. Mean survival time in the surgically treated dogs varied slightly according to mode of treatment; they survived 7 to 9 months longer than the untreated dogs. Dogs that underwent cryosurgery and local excision had the longest survival times (24 and 22 months, respectively). Statistical analysis disclosed a significantly longer survival time for dogs treated by excision or cryosurgery, as opposed to dogs undergoing biopsy only (P = 0.001). Statistical difference in survival times was not found between dogs that had mass excision and those that had cryosurgery.     

Histomorphometrical and stereological study of the oesophagus in the adult male Persian squirrel (Sciurus anomalus)

The Persian squirrel (Sciurus anomalus) is habitat in the Middle East countries and feed on pine acorns and other seeds. The present study was carried out to investigate the histological and volumetric features of the oesophagus in Persian squirrels. Five adult male Persian squirrels were included in the study. The cervical, thoracic and abdominal oesophagus of all subjects were processed routinely and sectioned in a serial manner. Then, the total volume of the oesophagus and its different layers were estimated using Cavalieri's principle. Histological assessment revealed a non‐keratinized stratified squamous epithelium lining the mucosa. No glands were seen in the lamina propria and submucosa. Lamina muscularis was present as a distinct layer of smooth muscle cells separating the lamina propria from the tunica submucosa. The tunica muscularis consisted of two distinct layers of striated muscle fibres: inner circular and outer longitudinal that was intermingled with few scattered smooth muscle fibres especially in the abdominal region. The thoracic region contained more amount of the lamina muscularis and tunica muscularis in comparison to the cervical or abdominal regions. The obtained results revealed that the histological structure of the Persian squirrel oesophagus has differences and similarities with other rodents and even with other species of squirrel. These findings would be useful to improve the knowledge in the areas of histological structure of the rodent digestive system.     

Functional suture-holding layer of the esophagus in the dog

Several investigators have stated that the suture-holding layer of the esophagus is the mucosa. In this study, the component layers of the esophagus were separated. Segments of the cervical esophageal wall, muscularis, submucosa, and submucosa-mucosa were each sutured, and the suture lines were subjected to tensile forces. When subjected to tensile force, all suture lines failed when sutures pulled through the tissue. The data were subjected to statistical analysis. Based on this analysis, it was concluded that the full esophageal wall had the greatest ability, and the muscularis the least ability, to hold sutures against tension. Therefore, when no significant difference in suture-holding ability between the submucosa alone and the submucosa-mucosa together was demonstrated, it was concluded that the submucosa was the suture-holding layer of the esophagus.     

Ultrasonographic features of pedunculated lipomas in two horses

Small intestine strangulation by pedunculated lipomas is a common cause of acute colic in horses. However, diagnosis of this condition prior to surgery may be difficult due to the poor specificity of the clinical signs. We describe the ultrasonographic findings of 2 horses presented for acute colic with a diagnosis of strangulating lipoma confirmed in surgery. Lipomas were identified as rounded and well‐defined, homogeneous hyperechoic structures, surrounded by distended small intestine loops and peritoneal fluid. Ultrasonographic identification of lipomas should be attempted during an abdominal scan, especially in horses with evidence of small intestinal ileus and/or obstruction.     

Über die intramuralen Blutgefäße des Enddarms vom Pferd (Equus przewalskii f. caballus)

The vascular system of the large intestine of 12 horses was examined by means of vascular corrosion casts, histology and transmission electron microscopy providing the following results. The Aa. et Vv. breves et longae leave the mesenteric vessels, respectively the subserously on the teniae lying cecal vessels to reach the tela subserosa at the mesenteric margin. The short vessels enter the deeper layers of the wall instantly, whereas the Aa. et Vv. longae move towards the submucosa by penetrating the muscular layers after a variable subserous course. The tela submucosa contains an arterial and a venous vascular plexus. In broader areas of the submucosa a three-dimensional vascular network can be found. This consists of a deep and a superficial vascular plexus, which are closely interconnected. The deep plexus is applied to the inner circular muscles, whereas the superficial plexus is adjacent to the muscularis mucosae. The (deep) arterial plexus receives its afflux from the Aa. breves et longae and supplies parts of the circular muscle layer with recurrent muscle branches. The vascularisation of the mucosa also originates from the submucosal (superficial) plexus. In the basal tunica mucosa, the ascending arteries form a transversal network from which arterioles branch into periglandular capillaries around each Lieberkühn crypt. Close to the lumen, a polygonal subepithelial capillary system is formed. The capillaries turn into postcapillary venules immediately below the epithelium of the mucosal surface. Veins move vertically through the submucosa to enter the submucosal plexus after few inflowing side branches. Branches of the subserous-submucosal connections form an intermuscular plexus between the circular and longitudinal muscular layer. This plexus supplies the capillaries of the tunica muscularis. The subepithelial capillaries are predominantly lined with a fenestrated endothelium, whereas the capillaries of the pericryptal mucosa mainly show a continuous endothelial lining. The latter contain multiple vesicles, which may fuse in order to form transcytoplasmic channels. Sphincter-like muscle bundles at the transition points from capillaries to venules may provide hemodynamic regulatory structures in the submucosa of the horse. Veins with circumferential cushions of smooth muscle fibres, so-called ‘throttle veins’, are also found.     

A thymoma as a cause of oesophageal obstruction in a dog

A case of oesophageal obstruction in a dog was caused by an intraluminal, pedunculated thymoma. The tumour was surgically excised and, eventually, the dog made a full recovery. Two days after being discharged from hospital, the dog developed acute myositis involving the temporal muscles which responded, without untoward sequelae, to steroid therapy.     

Gastrointestinal zygomycosis in suckling pigs

Gastrointestinal zygomycosis was diagnosed in 3 suckling pigs (10, 14, and 28 days old) with diarrhea that was unresponsive to treatment with broad-spectrum antibiotics. The 3 pigs were from separate farms, and littermates of the 3 pigs with similar clinical signs had died. At necropsy, 2 of the 3 pigs had catarrhal to fibrinonecrotic gastroenteritis, and the third pig had hemorrhagic gastritis without intestinal lesions. Microscopically, transmural necrosis of the stomach and intestines was associated with marked inflammatory cell infiltration and thrombosis and vasculitis of vessels of the lamina propria and submucosa. Numerous broad, irregularly branching, nonseptate, mucoraceous fungi were seen in the lumens of blood vessels and in the necrotic mucosa and submucosa.