Feline low-grade intestinal T cell lymphoma: a unique natural model of human indolent T cell lymphoproliferative disorder of the gastrointestinal tract.

Indolent T cell lymphoproliferative disorder (LPD) of the gastrointestinal tract (GI-TLPD) is a rare human primary gastrointestinal T cell lymphoma that was recently included in the 2016 revision of the World Health Organization classification of lymphoid neoplasms. Low-grade intestinal T cell lymphoma (LGITL), an emerging disease in the domestic cat, shares a number of features with human GI-TLPD. In this prospective study, we determined whether feline LGITL might serve as a model of human GI-TLPD. We analyzed clinical, laboratory, and radiological data and performed histopathological and molecular studies on small intestinal biopsies from 22 domestic cats diagnosed with LGITL. This cancer mostly affects aging cats, is associated with nonspecific gastrointestinal tract signs, and is usually characterized by an indolent course. A histopathological analysis indicated that LGITL was mainly located in the jejunum. The small intestinal lamina propria was infiltrated by large numbers of small CD3+ T cell lymphocytes with various CD4 and CD8 expression profiles (CD4+ CD8- (4 out of 11, 36%), CD4- CD8+ (3 out of 11, 27%), and CD4- CD8- (4 out of 11, 36%)). Intraepithelial lymphocyte (IEL) counts were elevated in all cases. Ki67 was expressed in lamina propria lymphocytes and IELs at a low level (<30%). Most LGITLs were labelled by antibodies against phosphorylated STAT5, but were negative for CD56 and phosphorylated STAT3. T cell receptor gamma chain gene monoclonality was found in 86% of cases. These findings confirmed that feline LGITL shares clinical and histopathological features with human GI-TLPD. Feline LGITL may therefore constitute a relevant model of the human disease.

Feline low-grade alimentary lymphoma: an emerging entity and a potential animal model for human disease.

BACKGROUND: Low-grade alimentary lymphoma (LGAL) is characterised by the infiltration of neoplastic T-lymphocytes, typically in the small intestine. The incidence of LGAL has increased over the last ten years and it is now the most frequent digestive neoplasia in cats and comprises 60 to 75% of gastrointestinal lymphoma cases. Given that LGAL shares common clinical, paraclinical and ultrasonographic features with inflammatory bowel diseases, establishing a diagnosis is challenging. A review was designed to summarise current knowledge of the pathogenesis, diagnosis, prognosis and treatment of feline LGAL. Electronic searches of PubMed and Science Direct were carried out without date or language restrictions. RESULTS: A total of 176 peer-reviewed documents were identified and most of which were published in the last twenty years. 130 studies were found from the veterinary literature and 46 from the human medicine literature. Heterogeneity of study designs and outcome measures made meta-analysis inappropriate. The pathophysiology of feline LGAL still needs to be elucidated, not least the putative roles of infectious agents, environmental factors as well as genetic events. The most common therapeutic strategy is combination treatment with prednisolone and chlorambucil, and prolonged remission can often be achieved. Developments in immunohistochemical analysis and clonality testing have improved the confidence of clinicians in obtaining a correct diagnosis between LGAL and IBD. The condition shares similarities with some diseases in humans, especially human indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. CONCLUSIONS: The pathophysiology of feline LGAL still needs to be elucidated and prospective studies as well as standardisation of therapeutic strategies are needed. A combination of conventional histopathology and immunohistochemistry remains the current gold-standard test, but clinicians should be cautious about reclassifying cats previously diagnosed with IBD to lymphoma on the basis of clonality testing. Importantly, feline LGAL could be considered to be a potential animal model for indolent digestive T-cell lymphoproliferative disorder, a rare condition in human medicine.

Congenital Partial Colonic Agenesis in Dogs and Cats: Clinical, Biological, Diagnostic Imaging, Endoscopic and Histopathologic Characterization, a Retrospective Study.

Congenital diseases of the large intestine of dogs and cats have scarcely been reported and mostly include fistula, atresia or colonic duplication. Cases of partial colonic agenesis have rarely been described. The purpose of this study was to report a cohort of dogs and cats diagnosed with partial colonic agenesis. The colon was measured during colonoscopy or contrast-radiography and compared to the average length described in the literature. Six dogs and 17 cats were retrospectively included. Depending on the case, partial colonic agenesis could represent an incidental finding or the likeliest cause of clinical signs. Diarrhea was reported in most cases, and no specific clinical or biological abnormality was observed. Median age of presentation was variable and long asymptomatic periods were common. Abdominal ultrasound was useful and identified a short colon in 14/17 cats but only in one dog. Endoscopy was useful to confirm the diagnosis and to identify associated lesions and complications. Among others, colonic stenosis was reported in 8/9 cases that had lifelong clinical signs and the shortest colon length. This anatomical abnormality could promote chronic inflammation that might generate fibrosis and ultimately stenosis.

ACVIM consensus statement guidelines on diagnosing and distinguishing low-grade neoplastic from inflammatory lymphocytic chronic enteropathies in cats.

BACKGROUND: Lymphoplasmacytic enteritis (LPE) and low-grade intestinal T cell lymphoma (LGITL) are common diseases in older cats, but their diagnosis and differentiation remain challenging. OBJECTIVES: To summarize the current literature on etiopathogenesis and diagnosis of LPE and LGITL in cats and provide guidance on the differentiation between LPE and LGITL in cats. To provide statements established using evidence-based approaches or where such evidence is lacking, statements based on consensus of experts in the field. ANIMALS: None. METHODS: A panel of 6 experts in the field (2 internists, 1 radiologist, 1 anatomic pathologist, 1 clonality expert, 1 oncologist) with the support of a human medical immunologist, was formed to assess and summarize evidence in the peer-reviewed literature and complement it with consensus recommendations. RESULTS: Despite increasing interest on the topic for clinicians and pathologists, few prospective studies were available, and interpretation of the pertinent literature often was challenging because of the heterogeneity of the cases. Most recommendations by the panel were supported by a moderate or low level of evidence. Several understudied areas were identified, including cellular markers using immunohistochemistry, genomics, and transcriptomic studies. CONCLUSIONS AND CLINICAL IMPORTANCE: To date, no single diagnostic criterion or known biomarker reliably differentiates inflammatory lesions from neoplastic lymphoproliferations in the intestinal tract of cats and a diagnosis currently is established by integrating all available clinical and diagnostic data. Histopathology remains the mainstay to better differentiate LPE from LGITL in cats with chronic enteropathy.

A case of feline gastrointestinal eosinophilic sclerosing fibroplasia associated with fungal colonisation: endoscopic features, treatment and follow-up.

Case summary: A 5-year-old castrated male domestic shorthair cat presented with a 3-month history of weight loss, chronic diarrhoea and vomiting. Examination revealed a large proximal duodenal lesion eventually diagnosed as feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) associated with fungal filaments. Histological examination was performed following endoscopic biopsy. Direct examination and mycological culture of the duodenal biopsies revealed the presence of a siphomycetous fungus, which was further identified as Rhizopus microsporus. Treatment with prednisolone and ciclosporin for 3 months led to complete resolution of the clinical signs and marked improvement of the endoscopic lesions. Specific fungal treatment with amphotericin B was poorly tolerated. Relevance and novel information: To the best of our knowledge, this is the first report of the characterisation of a siphomycetous fungus associated with FGESF lesions, and the first endoscopic description and diagnosis of FGESF without surgical biopsies. We hypothesise that the presence of R microsporus occurred because of disrupted mucosal integrity.

Comment on Kieslinger et al. A Recurrent STAT5BN642H Driver Mutation in Feline Alimentary T Cell Lymphoma. Cancers 2021, 13, 5238.

We have read with great interest the recently published article by M. Kieslinger et al. in Cancers Journal [...].

Digestive Diseases in Brachycephalic Dogs.

In addition to presenting with respiratory signs, many dogs with brachycephalic airway obstructive syndrome show digestive tract signs related to the same conformational abnormalities. A detailed diagnostic investigation is usually required, including clinicopathologic analyses, thoracic radiographs, fluoroscopic studies, abdominal ultrasound examinations and both upper airway and gastrointestinal tract endoscopy. In most cases, medical therapies are successful in managing clinical signs, but surgery can occasionally be required to resolve hiatal hernia or pyloric stenosis. In determining prognosis, the features of each individual case should be considered, with the overall prognosis depending on the severity and extent of all the identified lesions.

Surgical treatment of a distal oesophageal stricture by mucosal radial incision and dilation in a kitten with secondary megaoesophagus.

CASE SUMMARY: A 7-month-old intact female Maine Coon cat was presented with a 2-month history of regurgitations. Contrast radiographic and endoscopic examinations revealed a diffuse megaoesophagus secondary to a severe lower oesophageal stricture. An epiphrenic diverticulum was noted. Endoscopic balloon dilation was unsuccessful. Gastrotomy was thus performed in order to incise the oesophageal wall radially along the stricture site, and then to dilate the stricture. A diameter of 20 mm was reached. With the aim of preventing stricture recurrence, submucosal injections of triamcinolone acetonide were performed. An 18 Fr oesophagogastric feeding tube was placed and a left gastropexy was performed in order to exert some traction on the gastroesophageal junction, with the aim of reducing the oesophageal diverticulum. Twelve months postoperatively, clinical signs had completely resolved and follow-up radiographs revealed marked improvement of the oesophageal dilatation. RELEVANCE AND NOVEL INFORMATION: Lower oesophageal strictures should be considered when evaluating regurgitations or megaoesophagus in a kitten. Surgical mucosal radial incision is a therapeutic option in cases of lower oesophageal stricture refractory to balloon dilation, and can lead to a marked improvement of clinical signs and of the oesophagus diameter leading to clinical success.

Clinical, laboratory and ultrasonographic findings differentiating low-grade intestinal T-cell lymphoma from lymphoplasmacytic enteritis in cats.

BACKGROUND: Low-grade intestinal T-cell lymphoma (LGITL) is the most common intestinal neoplasm in cats. Differentiating LGITL from lymphoplasmacytic enteritis (LPE) is challenging because clinical signs, laboratory results, diagnostic imaging findings, histology, immunohistochemistry, and clonality features may overlap. OBJECTIVES: To evaluate possible discriminatory clinical, laboratory and ultrasonographic features to differentiate LGITL from LPE. ANIMALS: Twenty-two cats diagnosed with LGITL and 22 cats with LPE based upon histology, immunohistochemistry, and lymphoid clonality. METHODS: Prospective, cohort study. Cats presented with clinical signs consistent with LGITL or LPE were enrolled prospectively. All data contributing to the diagnostic evaluation was recorded. RESULTS: A 3-variable model (P < .001) consisting of male sex (P = .01), duration of clinical signs (P = .01), and polyphagia (P = .03) and a 2-variable model (P < .001) including a rounded jejunal lymph node (P < .001) and ultrasonographic abdominal effusion (P = .04) were both helpful to differentiate LGITL from LPE. CONCLUSIONS AND CLINICAL IMPORTANCE: Most clinical signs and laboratory results are similar between cats diagnosed with LGITL and LPE. However, male sex, a longer duration of clinical signs and polyphagia might help clinicians distinguish LGITL from LPE. On ultrasonography, a rounded jejunal lymph node, and the presence of (albeit small volume) abdominal effusion tended to be more prevalent in cats with LGITL. However, a definitive diagnosis requires comprehensive histopathologic and phenotypic assessment.

Endoscopic assessment of presumed acquired pyloric narrowing in cats: A retrospective study of 27 cases.

Acquired pyloric narrowing is a rare and poorly-documented condition in cats, but the endoscopic appearance of pyloric narrowing has never previously been reported. The objectives of this study were to describe the clinical, endoscopic and histological features in cats with gastrointestinal signs where the pylorus could not be passed during endoscopy, and to compare these data with a control group. Medical files of cats that underwent upper GI endoscopy by the same operator between 2006 and 2015 were reviewed. Cats for which the pylorus could not be passed were assigned to the case group, whilst those with an easily-passable pylorus were assigned to the control group. The case group comprised 27 cats and control group comprised 35 cats. Median age and weight were not different between groups, but there were more Siamese cats in the case group (6/27) compared with the control group (1/35; P = 0.04). Chronic vomiting was the main clinical sign in both groups, but the vomitus was more likely to contain food in case group (23/25) than in cats in control group (17/30; P < 0.01). Endoscopic findings confirmed gastric inflammation in both groups, whilst histological findings revealed similar lymphoplasmacytic infiltration of the gastric mucosa and the duodenum in most cases, neoplastic features being infrequent. Acquired pyloric narrowing is probably an underdiagnosed condition in adult cats. A possible association between pyloric narrowing and gastrointestinal inflammatory disease requires further study but, for now, it is recommended that multiple gastric, pyloric, and duodenal biopsies be acquired during the endoscopy.

Histopathologic, phenotypic, and molecular criteria to discriminate low-grade intestinal T-cell lymphoma in cats from lymphoplasmacytic enteritis.

BACKGROUND: Differentiation of low-grade intestinal T-cell lymphoma (LGITL) from lymphoplasmacytic enteritis (LPE) in cats is a diagnostic challenge for pathologists. OBJECTIVE: Characterize histologic, immunohistochemical, and molecular features of LGITL and LPE. ANIMALS: Forty-four client-owned cats, 22 diagnosed with LGITL and 22 with LPE. METHODS: Prospective, cohort study. Clinical suspicion of LGITL or LPE was based on persistent gastrointestinal signs, unresponsive to empirical treatments. All cats underwent a standardized diagnostic evaluation, including biopsy (preferentially full-thickness), and were diagnosed with LGITL or LPE after review of clinical, laboratory, sonographic, histologic, immunohistochemical, and clonality results. RESULTS: A monomorphic lymphocytic population (22/22, 100%) and in-depth mucosal infiltration (15/22, 68%) were hallmarks of LGITL. Epithelial patterns (nests and plaques) were significantly more frequent in LGITL (11/22, 50%) than in LPE (1/22, 5%) cases (P = .001). A CD3+ lymphocytic apical-to-basal gradient was observed in 9/22 (41%) of LGITL vs 1/22 (5%) of LPE cases (P = .004). Most LPE cases (17/18, 94%) featured marked fibrosis in the superficial part of the lamina propria. The Ki-67 20%- and 30%-thresholds discriminated between LGITL and LPE within both the epithelium (specificity >95%) and lamina propria (specificity >95%), respectively. All LGITL cases were CD3+ pSTAT3- and pSTAT5+. T-cell receptor gamma chain gene rearrangements indicated monoclonality in 86% of LGITL cases. Surprisingly, 70% of LPE cases featured monoclonality (40%) or monoclonality on a polyclonal background (30%). CONCLUSIONS AND CLINICAL IMPORTANCE: We identified new histologic, immunohistochemical, and clonality criteria to distinguish LGITL from LPE.

Comparison of clinical, endoscopic, and histologic features between dogs with chronic gastritis with and without lymphofollicular hyperplasia.

OBJECTIVE: To compare clinical, endoscopic, and histopathologic features between dogs with chronic gastritis (CG) with and without lymphofollicular hyperplasia (LFH). ANIMALS: 64 and 56 dogs with CG with (cases) and without (controls) LFH, respectively. PROCEDURES: The medical record database of a referral clinic was searched to identify dogs that underwent endoscopic examination of the upper portion of the gastrointestinal tract and were subsequently determined to have CG with or without LFH between October 2006 and February 2011. Signalment and clinical, endoscopic, and histologic findings were compared between cases and controls. Logistic regression was used to identify factors associated with CG with LFH. RESULTS: Compared with controls, cases were significantly younger and more likely to be of a brachycephalic phenotype. The proportions of dogs with a poor body condition or diarrhea were significantly lower and the proportions of dogs with inspiratory dyspnea, exercise intolerance, or hyperemia and discoloration of the gastric mucosa were significantly higher for the case group, compared with the control group. Inspiratory dyspnea, gastric mucosal hyperemia, and gastritis severity were positively associated, whereas poor body condition was negatively associated, with CG with LFH on multivariable logistic regression. CONCLUSIONS AND CLINICAL RELEVANCE: The strong positive association between inspiratory dyspnea and CG with LFH suggested that the condition may be a consequence of an increase in negative intrathoracic pressure rather than a distinct clinical entity. Prospective studies are warranted to elucidate the mechanism by which inspiratory dyspnea contributes to the development of CG with LFH.

An endoscopic method for semi-quantitatively measuring internal pyloric diameter in healthy cats: A prospective study of 24 cases.

The objectives of this study were to describe an endoscopic technique for semi-quantitative measurement of the internal pyloric diameter and apply this method to determine its typical size in a population of healthy cats. Twenty-four healthy adult cats, privately owned or originating from catteries, were prospectively recruited. Endoscopies were performed by the same investigator and cats with moderate to marked macroscopic inflammation were excluded. The internal pyloric diameter was measured with bespoke interchangeable biocompatible 'olives' (ranging from 4 to 12 mm in diameter) that could be attached to a guidewire. Attempts were made to pass the olives through the pylorus, in decreasing order of size, and the internal pyloric diameter was assumed to be equivalent to the size of the first olive that could successfully be passed. The median duration of the endoscopic procedure was <5 (interquartile range 2.7-5.4) minutes and all cats recovered quickly from the procedure without any complications. The median internal pyloric diameter in this population was 9 (interquartile range 9-10) mm, with most (23/24) cats having an internal pyloric diameter within ±1 mm of this measurement. There was no apparent effect of age, sex, breed or weight on the pyloric size. This study is the first to describe a quick and safe method for semi-quantitatively assessing the internal pyloric diameter in healthy adult cats. A prospective study is now warranted in order to determine the impact of gastrointestinal disease on pyloric diameter, for example cats with possible pyloric stenosis.

Development and validation of a novel clinical scoring system for short-term prediction of death in dogs with acute pancreatitis.

BACKGROUND: Acute pancreatitis (AP) is associated with a high death rate in dogs, but accurate predictors of early death are still lacking. OBJECTIVES: To develop a scoring system for prediction of short-term case fatality in dogs with AP. ANIMALS: One hundred sixty-nine dogs with AP including 138 dogs in the training cohort and 31 dogs in the validation cohort. METHODS: Multicenter, retrospective cohort study. Survival analysis was used to assess the associations with short-term death (within 30 days after admission). Independent predictors of death were identified by a stepwise selection method and used for the score calculation. RESULTS: Death rate within 30 days after admission was 33% in the training cohort. Four independent risk factors for short-term death were identified in the training cohort: presence of systemic inflammatory response syndrome, coagulation disorders, increased creatinine and ionized hypocalcemia. Canine Acute Pancreatitis Severity (CAPS) score was developed to predict short-term death, integrating these 4 factors in a weighted way. A simplified version of CAPS score (sCAPS) including respiratory rate instead of SIRS was also assessed. The area under the receiver-operating characteristic curve (AUC) of CAPS and sCAPS scores was 0.92 in the training cohort with an optimal cutoff of 11 (sensitivity, 89%; specificity, 90%) and 6 (sensitivity, 96%; specificity, 77%), respectively. CAPS and sCAPS score were validated in the validation cohort with respective AUC of 0.91 and 0.96. CONCLUSIONS AND CLINICAL IMPORTANCE: We propose 2 scoring systems that allow early and accurate prediction of short-term death in dogs with AP.

Is electroejaculation a safe procedure in cats? An endoscopic and histological prospective blinded study.

Transrectal electrostimulation is a technique used for semen collection in several animals including felids, but also in humans with spinal cord injuries and in specific cases of anejaculation. To the authors' knowledge, safety and innocuity on rectal mucosa has not yet been assessed histologically. A prospective study was performed on 10 European cats in order to determine the impact of electroejaculation on the rectal mucosa, by performing endoscopic and histological evaluation of the rectal mucosa. Endoscopic evaluation was performed before and after semen collection. Standardized biopsy specimens were collected immediately after semen collection, on the site of electrostimulation and on the proximal part of the descending colon as a control, for further double-blinded histopathological evaluation. The degree of inflammation was evaluated following the criteria from the WSAVA Gastrointestinal Standardization Group. Semen collection by electrostimulation did not induce significant histological and endoscopic lesions. Electrostimulation may therefore be considered as a safe technique to collect semen in cats.

Esophageal leiomyoma in a dog causing esophageal distension and treated by transcardial placement of a self-expanding, covered, nitinol esophageal stent.

CASE DESCRIPTION A 10-year-old spayed female Rottweiler was referred for evaluation because of a 2-month history of regurgitation and weight loss, despite no apparent change in appetite. The dog had received antiemetic and antacid treatment, without improvement. CLINICAL FINDINGS Physical examination revealed a low body condition score (2/5), but other findings were unremarkable. Diffuse, global esophageal dilatation was noted on plain thoracic radiographs, and normal motility was confirmed through videofluoroscopic evaluation of swallowing. Transhepatic ultrasonographic and CT examination revealed a circumferential, intraparietal lesion in the distal portion of the esophagus causing distal esophageal or cardial subobstruction and no metastases. Incisional biopsy of the lesion was performed, and findings of histologic examination supported a diagnosis of esophageal leiomyoma. TREATMENT AND OUTCOME In view of numerous possible complications associated with esophageal surgery, the decision was made to palliatively treat the dog by transcardial placement of a self-expanding, covered, nitinol esophageal stent under endoscopic guidance. Two weeks after stent placement, radiography revealed complete migration of the stent into the gastric lumen. Gastrotomy was performed, and the stent was replaced and fixed in place. Twenty-four months after initial stent placement, the dog had a healthy body condition and remained free of previous clinical signs. CLINICAL RELEVANCE Diffuse benign muscular neoplasia should be considered as a differential diagnosis for acquired esophageal dilatation in adult and elderly dogs. In the dog of this report, transcardial stent placement resulted in resolution of the clinical signs, with no apparent adverse effect on digestive function. The described procedure could be beneficial for nonsurgical treatment of benign esophageal tumors in dogs.

Ultrasonographic, endoscopic and histological appearance of the caecum in clinically healthy cats.

Objectives The aim of the study was to describe the ultrasonographic and endoscopic appearance and characteristics of the caecum in asymptomatic cats, and to correlate these findings with histology. Methods Ex vivo ultrasonographic and histologic evaluations of a fresh caecum were initially performed. Then, 20 asymptomatic cats, privately owned or originating from a reproductive colony, were recruited. All cats had an ultrasonographic examination of the ileocaecocolic junction, where the thickness of the caecal wall, ileocolic lymph nodes and the echogenicity of the local fat were assessed. They all underwent a colonoscopy with a macroscopic assessment of the mucosa and biopsies for histology. Results An ultrasonographic hypoechoic nodular inner layer, which corresponded to the coalescence of multiple lymphoid follicles originating from the submucosa and protruding in the mucosa on histology, was visible in all parts of the caecum. The combined mucosa and submucosa was measured ultrasonographically and defined as the follicular layer. Although all cats were asymptomatic, 3/19 cats showed mild caecal inflammation on histology. The most discriminatory ultrasonographic parameter in assessing this subclinical inflammation was the thickness of the follicular layer at the entrance of the caecum, with a cut-off value of 2.0 mm. All cats (20/20) showed some degree of macroscopic 'dimpling' of the caecal mucosa on endoscopy. Conclusions and relevance Lymphoid follicles in the caecal mucosa and submucosa constitute a unique follicular layer on ultrasound. In asymptomatic cats, a subtle, non-clinically relevant inflammation may exist and this is correlated with an increased thickness of the follicular layer on ultrasound. On endoscopy, a 'dimpled aspect' to the caecal mucosa is a normal finding in the asymptomatic cat.

Ultrasonographic, endoscopic and histological appearances of the caecum in cats presenting with chronic clinical signs of caecocolic disease.

Objectives This study aimed to describe the ultrasonographic, endoscopic and histological characteristics of the caecum and ileocaecocolic junction in cats suffering from chronic clinical signs compatible with caecocolic disease. Methods Cats presenting with clinical signs suggestive of a caecocolic disease were prospectively recruited. All cats underwent an ultrasonographic examination of the caecum, ileum, colon, ileocolic lymph nodes and local mesenteric fat, in addition to comprehensive abdominal ultrasonography. This was followed by a colonoscopy with a macroscopic assessment of the caecocolic mucosa; caecocolic tissue samples were systematically collected for histologic analysis. Results Eighteen cats were included. Eleven of 18 cats had ultrasonographic abnormalities adjacent to the ileocaecocolic junction (lymphadenopathy, local steatitis) and 13/18 cats had abnormalities directly related to the junction (wall thickening, loss of wall layering). Seventeen of 18 cats had at least one ultrasonographic abnormality. Endoscopically, hyperaemia, oedema, discoloration and/or erosions were found in all cats. Each cat was classified as having mild or moderate-to-severe lesions according to endoscopic results; no classification could be established statistically for ultrasonographic results. The accentuation of the dimpled pattern tended to be inversely related to the severity of endoscopic lesion scoring. Histologically, a large proportion of cats showed typhlitis (13/16), one had lymphoma and two were normal. All cats with typhlitis also had colitis. There was only slight agreement between endoscopic and histological caecal results regarding the severity of lesions. Loss of caecal wall layering on ultrasound was found in 7/18 cats and, surprisingly, did not appear as a reliable predictor of the severity of inflammation or of malignancy; neither did local steatitis nor lymph node size. Conclusions and relevance Ultrasonography and endoscopy should not be used as the sole methods to investigate the ileocaecocolic region in cats with clinical signs suggestive of caecocolic disease. The presence of chronic clinical signs should routinely prompt histological biopsy.

Can clinical signs, clinicopathological findings and abdominal ultrasonography predict the site of histopathological abnormalities of the alimentary tract in cats?

OBJECTIVES: Many cats with gastrointestinal signs have coexisting abnormalities in the intestine, liver and pancreas. Investigations typically involve clinicopathological tests, diagnostic imaging and biopsy, either at coeliotomy or by non-invasive means. While exploratory coeliotomy enables all organs to be sampled simultaneously, it is invasive and might not be necessary. The aim of the current study was to assess the performance of preliminary clinical information in predicting the histopathological presence of abnormalities in alimentary tract organs in cats. METHODS: The records of 38 cats with alimentary tract signs, which had ultimately undergone exploratory coeliotomy and surgical biopsy, were reviewed. The clinical signs, clinicopathological findings, diagnostic imaging findings and histopathology results were reviewed. RESULTS: On histopathological analysis, lesions were detected in 29/37 (78%) liver biopsies, in 29/35 (83%) gastrointestinal biopsies and in 17/37 (46%) pancreatic samples, the majority of which were inflammatory in nature. Clinical signs were generally poor markers of the presence of lesions in the alimentary tract. Further, while liver enzyme activity was relatively specific (88-100%) for detecting histopathological abnormalities in the liver, sensitivity was poor (11-50%). Pancreatic histopathological abnormalities were present in 1/3 of the cats with a positive pancreas-specific lipase result, and in 6/8 cats with a negative result. While relatively specific (57-100%) for both intestinal (57-100%) and hepatic (71-80%) histopathological abnormalities, abdominal ultrasonography lacked sensitivity for both organs (intestine 50-80%; liver 20-25%). In contrast, ultrasonography was relatively sensitive (50-80%), but not specific (17-22%) for detecting pancreatic lesions. CONCLUSIONS AND RELEVANCE: Clinical signs, and clinicopathological and ultrasonographic abnormalities lack precision for hepatic and pancreatic histopathological lesions in cats with alimentary tract signs, and cannot reliably predict from which organs biopsies should be collected. Arguably, therefore, exploratory coeliotomy is necessary to determine the site of histopathological abnormalities in feline alimentary tract disorders.