Radiographic findings and clinical factors in dogs with surgically confirmed or presumed colonic torsion

Colonic torsion is a life‐threatening condition in dogs and radiographic findings for this condition have not been well described. The purpose of this retrospective case series was to describe radiographic findings and clinical signs in a group of dogs with colonic torsion. Inclusion criteria were dogs presenting during the period of 2006 and 2016, and that had abdominal radiography and a surgically confirmed or presumed diagnosis of colonic torsion. For each dog, clinical data were recorded from medical records and imaging findings were recorded from retrieved plain radiographs and positive contrast radiographs in which barium enema was performed. Fourteen dogs met inclusion criteria. Of these, nine dogs had colonic torsion confirmed at surgery, with five dogs having surgical confirmation of colonic congestion or mesenteric torsion. Radiographic findings included segmental distention of the colon (14/14), focal narrowing of the colon (11/14), displacement of cecum (11/14), displacement of descending colon (14/14), and mild to no small intestinal distention (14/14). In cases where barium enema was performed, focal narrowing of the colon and longitudinal striations that course in a helical pattern were identified, termed the “torsion sign.” Vomiting was the most common clinical sign observed (12/14), followed by abdominal pain in a small majority of cases (8/14). Severe abdominal pain and hypovolemic shock were uncommon in the patients reported (3/14). Colonic torsion should be considered as a differential diagnosis for dogs with radiographic segmental colonic distention with displacement of the descending colon and cecum. Barium enema is recommended for more definitive diagnosis.     

CT characteristics of primary splenic torsion in eight dogs

Splenic torsion is a rare potentially life‐threatening condition characterized by rotation of the spleen around the gastrosplenic and phrenosplenic ligaments leading to occlusion of venous drainage and arterial supply. This retrospective study describes the CT characteristics for dogs with surgically confirmed splenic torsion from 2013 to 2018 using the submissions to a large multinational teleradiology database. Eight dogs had the splenic torsion confirmed with surgery. Seven of eight cases had histology confirming congestion, hemorrhage, and necrosis, and one had concurrent myelolipoma infiltration. The CT characteristics included an enlarged (8/8), rounded (7/8), folded C‐shaped spleen (8/8) with a difference of median parenchymal attenuation between pre‐ and postcontrast of +1.15 HU (Hounsfield units). Other common features included a mainly homogeneous parenchyma on pre‐ and post‐contrast images (6/8), lack of subjective and objective vascular and parenchymal contrast enhancement (6/8) and free peritoneal fluid (6/8). A “whirl sign” was seen in the majority of cases (7/8) alongside a strongly hyperattenuating center (95‐416 HU) on the precontrast images (5/7), which has not been previously described in the veterinary literature. Gastric position was normal in all cases. More variable CT characteristics of the confirmed torsions were attributable to suspected partial torsion and myelolipomatous infiltration. Overall, primary splenic torsion confirmed with surgery showed consistent characteristics on CT.     

Radiographic and CT features of colonic entrapment due to an omental rent in a dog

A 2‐year‐old female spayed Great Dane presented for inappetence and lethargy. Abdominal radiographs revealed a severely gas‐distended segment of colon. Computed tomography was performed and characterized a 180° anticlockwise colonic torsion with entrapment in a mesenteric/omental rent without vascular compromise. Exploratory laparotomy confirmed entrapment, but not colonic torsion. Computed tomography provided important information to assist clinical management decisions for this dog with colonic entrapment.     

Effects of heparin treatment on colonic torsion-associated hemodynamic and plasma eicosanoid changes in anesthetized ponies

Large colon torsion frequently is a fatal condition in horses. The purpose of the study reported here was to determine systemic arterial pressure, plasma eicosanoid concentrations, colonic blood flow, vascular resistance, tissue pH, and morphologic features associated with large colon torsion and detorsion, and to evaluate the effects of sodium heparin (80 IU/kg of body weight, IV) treatment on these values. Values were determined in 20 anesthetized ponies that were randomly assigned into 4 equal groups: control; control/heparin; torsion; torsion/heparin. Torsions were created by a 720 degrees rotation of the cecum and colon around their long axes at the sternal and diaphragmatic flexures. After 1 hour of torsion, the torsion was corrected and the colon was allowed to reperfuse for 1 hour. Heparin was administered 30 minutes into the experiment. Parametric data were analyzed (P less than or equal to 0.05), using split-plot analysis of variance, with differences between means evaluated with a modified Bonferroni t test; histopathologic data were analyzed (P less than or equal to 0.05) with a Kruskal-Wallis one-way analysis of variance by ranks. Heparin prevented colonic detorsion-induced hypotension and increases in vascular resistance and thromboxane concentration, and it significantly increased colonic blood flow for 40 minutes during reperfusion. Heparin did not alter prostacyclin concentration or the histologic appearance of the large colon.     

Diagnosis and surgical management of vascular ectasia in a dog

CASE DESCRIPTION: An 8-year-old male Golden Retriever was evaluated because of an 8-week history of intermittent diarrhea with melena and hematochezia that were not responsive to medical treatment and resulted in severe anemia. CLINICAL FINDINGS: Exploratory celiotomy with intestinal and colonic biopsy revealed mild enterocolitis but did not result in diagnosis of the cause of melena and hematochezia. Endoscopy of the upper portion of the gastrointestinal tract and colonoscopy were performed. Multifocal areas of coalescing, tortuous mucosal blood vessels were observed in the cecum and all regions of the colon. A diagnosis of vascular ectasia (VE) was made on the basis of the endoscopic and histologic appearance of the lesions. TREATMENT AND OUTCOME: An ileorectal anastamosis was performed. Melena and hematochezia resolved within 3 days after surgery, and the anemia resolved within 6 weeks after surgery. Surgical resection of the cecum and colon and feeding of a highly digestible diet resulted in long-term (22 months) resolution of clinical signs. CLINICAL RELEVANCE: Initial exploratory celiotomy with intestinal and colonic biopsy failed to reveal the VE lesions responsible for the melena, hematochezia, and anemia. Endoscopic evaluation was necessary for detection of the colonic VE lesions. Surgical resection of the cecum and colon and feeding of a highly digestible diet may result in a favorable outcome in affected dogs.     

Obstruction of the descending colon due to torsion of the cecum through a mesocolic defect in a cow

A cow was evaluated for acute onset of abdominal pain and decreased milk production. Physical examination revealed narrowing of the descending colon. Exploratory laparotomy revealed mesocolic defect and torsion of the cecum around the descending colon. After surgical correction of the cecal torsion, the cow recovered rapidly. The mesocolic defect could not be closed, and the history did not indicate a cause for the mesocolic defect.     

MICRONODULAR ULTRASOUND LESIONS IN THE COLONIC SUBMUCOSA OF 42 DOGS AND 14 CATS

Micronodular ultrasound lesions have been detected in the colonic submucosa of dogs and cats at our hospital. The lesions had rounded/oval shapes, measured 1–3 mm in size, and exhibited a hypo/anechoic ultrasonographic pattern. To our knowledge, these lesions have not been previously reported in human or veterinary patients. The purpose of this retrospective study was to determine whether micronodular lesions were associated with other abdominal ultrasound abnormalities or clinical findings. Medical records of dogs and cats with sonographic reports describing micronodular lesions within the colonic submucosa were reviewed. Concurrent ultrasonographic abnormalities were recorded and compared with clinical sidgns and follow‐up data. A total of 42 dogs and 14 cats met inclusion criteria. Concurrent sonographic abnormalities included the following: increased colon wall thickness (12.5%); small bowel wall thickening, altered layering, and/or hyperechoic mucosa (45%); abdominal effusion (29%); caudal mesenteric lymphadenopathy (46%); mesenteric lymphadenopathy (27%); and pericolic peritoneal fat reactivity (9%). Fifty of 56 animals presented with diarrhea. Twenty‐seven cases had clinical signs of colitis and ultrasonographic lesions were limited to the colonic submucosa. In nine cases, follow‐up examination at 6–8 weeks showed resolution of clinical and ultrasonographic signs. Ultrasonographic and clinical examinations in 17 patients at 12–18 months and in 20 patients at 18–30 months from initial diagnosis showed resolution of submucosal lesions and clinical signs of enteropathy. The authors propose that micronodular submucosal ultrasound lesions may represent reactive intraparietal lymphoid follicles and may be indicators of colonic inflammatory diseases in dogs and cats.     

Body cavity lipomas in six dogs

Histologically confirmed lipomas were surgically removed from the thoracic or abdominal cavities of six dogs. Three dogs had a large intra-abdominal mass causing severe abdominal distension. Two dogs had a mass extending into the pelvic canal, compressing the colon and causing obstipation. One dog with an intrathoracic mass had a history of coughing and intermittent cyanosis. All dogs had complete resolution of signs after surgical resection of the tumour. Recurrence occurred in one dog with an abdominal lipoma, two years after the initial surgery. This recurrent lipoma was treated successfully by surgical resection.     

Volvulus of the colon in a Cat

We report the first case of colonic volvulus in a cat. A 12-year old spayed, female domestic shorthair cat with chronic bowel disease presentated with one-day history of lethargy and anorexia. Physical examination abnormalities included cachexia, poor perfusion, and poor skin turgor. A large, non painful, gas-filled, tubular structure, occupying the majority of the abdominal cavity was noted by palpation. Abdominal radiographs revealed a gas-filled displaced colon. Exploratory laparotomy confirmed a volvulus at the root of the colonic mysetery, along with a partial torsion of the distal colon. The majority of the colon was determined to be necrotic and was surgically resected. Due to persistent hypotension and perceived poor prognosis, the cat was euthanized.     

Ultrasonographic visualization of colonic mesenteric vasculature as an indicator of large colon right dorsal displacement or 180�� volvulus (or both) in horses

Visualization of colonic mesenteric vasculature during transabdominal ultrasonographic examination of horses with colic can be a predictor of right dorsal displacement of the large colon or 180° large colon volvulus, or both. Medical records of 82 horses having had surgical treatment of colic and having received a transabdominal ultrasonographic examination on admission were reviewed. Colonic mesenteric vessels were sonographically identified coursing laterally on the right side of the abdomen in 24 of the 82 cases. Horses with colonic vessels identified on ultrasound were 32.5 times more likely to be diagnosed at surgery with either large colon right dorsal displacement or 180° large colon volvulus than those in which vessels were not seen (P < 0.001). Visualization of colonic mesenteric vessels on ultrasound provided a sensitivity of 67.7%, specificity of 97.9%, positive predictive value of 95.8%, and negative predictive value of 81% for large colon right dorsal displacement or 180° large colon volvulus, or both.     

IMAGING DIAGNOSIS—ACUTE MESENTERIC ISCHEMIA ASSOCIATED WITH HYPERTROPHIC CARDIOMYOPATHY IN A CAT

A middle‐aged cat was presented with vomiting, diarrhea, and pelvic limb paresis. Radiography showed cardiomegaly, interstitial pulmonary infiltration, distended intestinal loops, and portal venous gas. Hypertrophic cardiomyopathy (HCM) was confirmed. On CT, thrombi were identified at the abdominal aorta, superior mesenteric artery, bilateral renal arteries, and cauda vena cava at the level of the iliac vein bifurcation. Dilated and gas‐filled loops of bowel with a “paper thin wall” were observed on CT images and were considered indicative of necrotic bowel. This case report describes the CT findings of acute mesenteric ischemia associated with HCM in a cat.     

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.     

Pythiosis of the digestive tract in dogs from Oklahoma

Enteric pythiosis was diagnosed in nine dogs in Oklahoma. Eight dogs had anorexia and weight loss. Two of these dogs had diarrhea; two dogs exhibited vomiting and diarrhea; and one dog had vomiting. One dog presented with dysphagia. Seven dogs had either a palpable or radiographically visible abdominal mass. These seven dogs had localized regions of mucosal ulceration and thickened gastric or intestinal walls with some involvement of the adjacent mesentery or omentum. Two dogs had enlarged regional mesenteric lymph nodes. One dog that presented with dysphagia had an oropharyngeal mass involving the larynx and cranial esophagus. Microscopically, there was transmural chronic sclerosing and granulomatous to pyogranulomatous inflammation with arteritis. Pythium spp. were identified in all specimens by immunohistochemistry.     

Triple‐phased mesenteric CT angiography using a test bolus technique for evaluation of the mesenteric vasculature and small intestinal wall contrast enhancement in dogs

Computed tomography angiography is widely used for the assessment of various mesenteric vascular and bowel diseases in humans. However, there are only few studies that describe CT angiography application to mesenteric vessels in dogs. In this prospective, experimental, exploratory study, the mesenteric vasculature and enhancement pattern of the intestinal wall were evaluated on triple‐phase CT angiography, and improvement of the visibility of vasculature was assessed on multiplanar reformation, maximum intensity projection, and volume rendering technique. After test bolus scanning at the level of the cranial mesenteric artery arising from the aorta, mesenteric CT angiography was performed in 10 healthy, male, Beagle dogs. Scan delay was set based on time‐to‐attenuation curves, drawn by placing the regions of interest over the aorta, intestinal wall, and cranial mesenteric vein. Visualization and enhancement of mesenteric arteries and veins were evaluated with multiplanar reformation, maximum intensity projection, and volume rendering techniques. The degree of intestinal wall enhancement was assessed on the transverse images in precontrast, arterial, intestinal, and venous phases. Pure arterial images were obtained in the arterial phase. Venous phase images allowed good portal vascular mapping. All CT angiography images were of high quality, allowing for excellent visualization of the anatomy of mesenteric vasculature including the small branches, particularly on maximum intensity projection and volume rendering technique. Distinct contrast enhancement of the intestinal wall was observed in both intestinal and venous phases. Findings indicated that this technique is feasible for the evaluation of mesenteric circulation in dogs.     

Predisposing factors for small colon impaction in horses and outcome of medical and surgical treatment: 44 cases (1999-2004)

OBJECTIVE: To identify factors associated with development of small colon impaction in horses and with selection of medical versus surgical treatment and to determine the prognosis for affected horses following medical or surgical management. DESIGN: Retrospective case series. ANIMALS: 44 horses with primary impaction of the small colon. PROCEDURES: Medical records were reviewed for signalment, history, clinical findings, treatment (medical vs surgical), hospitalization time, and outcome. For comparison purposes, the same information was collected for 83 horses with primary impaction of the large colon. RESULTS: Diarrhea was the only factor found to be associated with development of small colon impaction. Horses with small colon impaction were 10.8 times as likely to have diarrhea at the time of initial examination as were horses with large colon impaction. Abdominal distension was the only factor associated with use of surgical versus medical treatment. Horses with small colon impaction that were treated surgically were 5.2 times as likely to have had abdominal distension at the time of admission as were horses with small colon impaction that were treated medically. Overall, 21 of 23 (91%) horses treated medically and 20 of 21 (95%) horses treated surgically survived to discharge. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that diarrhea may be a risk factor for development of small colon impaction and that horses with small colon impaction that have abdominal distension at the time of initial examination are more likely to require surgical than medical treatment.     

Longitudinal colonic torsion as a cause of tenesmus in an adult Irish Water Spaniel

CASE HISTORY: Torsion of the descending colon was diagnosed by barium enema radiography in an adult Irish Water Spaniel which had presented with tenesmus of 24 h duration. Treatment involved exploratory laparotomy, repositioning of the colon, colopexy and repair of a mesenteric rent. No definitive cause of the torsion could be established. The dog made an uneventful recovery from surgery. CLINICAL RELEVANCE: Animals presenting with constipation of undetermined cause should have large intestinal obstruction ruled out prior to administering bowel cleansing solutions per os and/or colonic enemas. Colonic obstruction by torsion should be considered as a possible differential diagnosis in all cases of tenesmus.     

Successful outcome after a single endoscopic fecal microbiota transplantation in a Shiba dog with non-responsive enteropathy during the treatment with chlorambucil

A 7-year 6-month-old, castrated male Shiba dog presented with a 1-month history of lethargy, anorexia, vomiting, and frequent watery diarrhea. Weight loss, hypoalbuminemia, anemia, and leukocytosis were detected at the first visit. The dog was diagnosed with non-responsive enteropathy (NRE) based on clinical and histopathological examinations. Since the dog did not respond to the immunosuppressive drugs, fecal microbiota transplantation (FMT) was performed during the treatment with chlorambucil. A single endoscopic FMT into the cecum and colon drastically recovered clinical signs and clinicopathological abnormalities and corrected dysbiosis in the dog. No recurrence or adverse events were observed. The present case report suggests that FMT, possibly together with chlorambucil, might be a treatment option for NRE in Shiba dogs that have poorer prognosis compared with other dog breeds.     

Experimental infection of cats with Tritrichomonas foetus.

OBJECTIVE: To determine whether infection with Tritrichomonas foetus causes diarrhea in specific-pathogen-free or Cryptosporidium coinfected cats. ANIMALS: 4 cats with subclinical cryptosporidiosis (group 1) and 4 specific-pathogen-free cats (group 2). PROCEDURE: Cats were infected orogastrically with an axenic culture of T. foetus isolated from a kitten with diarrhea. Direct microscopy and protozoal culture of feces, fecal character, serial colonic mucosal biopsy specimens, and response to treatment with nitazoxanide (NTZ; group 1) or prednisolone (groups 1 and 2) were assessed. RESULTS: Infection with T. foetus persisted in all cats for the entire 203-day study and resulted in diarrhea that resolved after 7 weeks. Group-1 cats had an earlier onset, more severe diarrhea, and increased number of trichomonads on direct fecal examination, compared with group-2 cats. Use of NTZ eliminated shedding of T. foetus and Cryptosporidium oocysts, but diarrhea consisting of trichomonad-containing feces recurred when treatment was discontinued. Prednisolone did not have an effect on infection with T. foetus but resulted in reappearance of Cryptosporidium oocysts in the feces of 2 of 4 cats. During necropsy, T. foetus was isolated from contents of the ileum, cecum, and colon. Tritrichomonas foetus organisms and antigen were detected on surface epithelia and within superficial detritus of the cecal and colonic mucosa. CONCLUSIONS AND CLINICAL RELEVANCE: After experimental inoculation in cats, T. foetus organisms colonize the ileum, cecum, and colon, reside in close contact with the epithelium, and are associated with transient diarrhea that is exacerbated by coexisting cryptosporidiosis but not treatment with prednisolone.     

Upregulation of toll-like receptors in chronic enteropathies in dogs

BACKGROUND: Inflammatory bowel disease (IBD) is thought to result from a dysregulated interaction between the host immune system and commensal microflora. Toll-like receptors (TLRs) recognize microbe-associated molecular patterns (MAMPs), but their role in enteropathies in dogs is unknown. HYPOTHESIS: That there is a dysregulation of TLRs recognizing bacterial MAMPs in dogs with IBD. ANIMALS: Sixteen healthy beagles and 12 dogs with steroid-treated (ST) and 23 dogs with food-responsive (FR) diarrhea. METHODS: Prospective, observational study. mRNA expression of canine TLR2, 4, and 9 was evaluated by quantitative real-time RT-PCR in duodenal and colonic biopsies obtained before and after standard therapy. Samples from control dogs were taken at necropsy, with additional biopsies of stomach, jejunum, ileum, and mesenteric lymph node in 6 dogs. RESULTS: There were significant differences (P< or = .017) in expression of TLR2, 4, and 9 between the 6 sampled locations in healthy control dogs (lymph node > small intestine > or = colon). Before therapy, ST expressed more mRNA than control dogs for all 3 receptors (P < .05). There were no significant differences between pretreatment and posttreatment values, even though 32/35 dogs improved clinically. No associations were found when comparing receptor mRNA expression with either histology or clinical activity scores. CONCLUSIONS AND CLINICAL IMPORTANCE: Bacteria-responsive TLR2, 4, and 9 are upregulated in duodenal and colonic mucosa in IBD. This might lead to increased inflammation through interaction with the commensal flora. The absence of significant changes after therapy despite clinical improvement might point toward the existence of a genetic predisposition to IBD as described in human IBD.     

ULTRASONOGRAPHIC CHARACTERIZATION OF FELINE ILEOCECOCOLIC ABNORMALITIES

The clinical signs of 29 cats with ultrasonographic abnormalities at the ileocecocolic junction were reviewed. Twenty‐eight cats had gastrointestinal signs, with acute vomiting and diarrhea being most prevalent. Eighteen of 29 cats had enlarged cecal lymph nodes. Focal hyperechoic mesenteric fat was noted in 18 of 29 cats, and mild focal fluid accumulation was seen in seven of 29 cats. Six cats had a round cecum, and eight cats had cecal content. The cecal wall was thickened in 19 cats, and the ileal wall was mildly thickened in six cats. Three cats had changes involving the ascending colon adjacent to the ileocecocolic junction. Fourteen cats had no ultrasonographic evidence of changes in the remainder of the gastrointestinal tract, and 13 of these 14 cats were symptomatic for gastrointestinal disease. Four cats with resolution of the ultrasonographic changes also had resolution of clinical signs. These results suggest that ultrasonographic abnormalities at the level of the ileocecocolic junction in cats are clinically significant and are seen in cats with acute vomiting or diarrhea. Fine‐needle aspirates and biopsies of the ileocecocolic area had a low diagnostic yield. When no other gastrointestinal abnormalities are detected, we therefore recommend follow‐up ultrasound examinations of these patients.