Utility of endoscopic biopsies of the duodenum and ileum for diagnosis of inflammatory bowel disease and small cell lymphoma in cats.

BACKGROUND: Endoscopic duodenal biopsies are relatively convenient, minimally invasive tests for infiltrative intestinal disorders of cats. Ileal endoscopic biopsies might not be performed because of technical difficulty and effort required to prepare the colon. It is not known whether or not histopathology of feline duodenal and ileal biopsies for detection of inflammatory bowel disease (IBD) and small cell lymphoma (SC-LSA) provides comparable results. OBJECTIVES: To evaluate the agreement between endoscopic biopsies of duodenum and ileum in cats with IBD and SC-LSA. ANIMALS: Seventy client-owned cats with gastrointestinal disease and adequate duodenal and ileal tissue biopsies obtained endoscopically. METHODS: Retrospective study: Search of medical records of cats with enteropathy and endoscopy. Samples were blinded and re-evaluated by single pathologist (JM) for quality, number of biopsies, and diagnosis according to WSAVA standards. Agreement of IBD and SC-LSA diagnoses among biopsy sites assessed using Cohen's Kappa. RESULTS: Eighteen of 70 cats (26%) were diagnosed with SC-LSA in duodenum, ileum, or both. Of these 18 cats, 7 (39%) were diagnosed with only duodenal SC-LSA, 8 (44%) were diagnosed with only ileal SC-LSA, and 3 (17%) had SC-LSA in both duodenum and ileum. There was poor agreement on diagnosis between duodenal and ileal biopsies (kappa = 0.23). CONCLUSIONS AND CLINICAL IMPORTANCE: Although review by a single pathologist remains a limitation of this study, results suggest that there is a population of cats in which diagnosis of SC-LSA can be found only by evaluation of ileal biopsies. Clinicians should consider performing both upper and lower GI endoscopic biopsies in cats with infiltrative small bowel disease.

Effect of tissue processing on assessment of endoscopic intestinal biopsies in dogs and cats.

BACKGROUND: Prior studies failed to detect significant association between hypoalbuminemia and small intestinal lesions. HYPOTHESIS: Use of pictorial templates will enhance consistency of interpathologist interpretation and identification of intestinal lesions associated with hypoalbuminemia. ANIMALS: Tissues from 62 dogs and 25 cats examined as clinical cases at 7 referral veterinary practices in 4 countries. METHODS: Retrospective, observational study. Histopathology slides from sequential cases undergoing endoscopic biopsy were examined by 4 pathologists by pictorial templates. Changes for 9 microscopic features were recorded as normal, mild, moderate or severe, and 2- and 4-point scales were tested for consistency of interpretation. Logistic regression models determined odds ratios (OR) of histologic lesions being associated with hypoalbuminemia while kappa statistics determined agreement between pathologists on histologic lesions. RESULTS: There was poor agreement (kappa = -0.013 to 0.3) between pathologists, and institution of origin of slides had effect (kappa = 1.0 for 3 of 4 lesions on slides from Institution 5) on agreement between pathologists on selected histologic features. Using 2 point as opposed to 4-point grading scale increased agreement between pathologists (maximum kappa = 0.69 using 4-point scale versus maximum kappa = 1.0 using 2-point scale). Significant association (P = .019- .04; 95% OR = 3.14-10.84) between lacteal dilation and hypoalbuminemia was found by 3 pathologists. CONCLUSIONS AND CLINICAL IMPORTANCE: Substantial inconsistency between pathologists remains despite use of pictorial template because of differences in slide processing. Distinguishing between mild and moderate lesions might be important source of the disagreement among pathologists.

Comparison of histopathologic findings in biopsies from the duodenum and ileum of dogs with enteropathy.

BACKGROUND: In the investigations of dogs with chronic small intestinal diarrhea collection of ileal biopsies lengthens procedural time and has been of uncertain value. OBJECTIVES: To evaluate whether there was agreement between histologic changes present in samples of duodenal and ileal mucosa, and hence to provide initial information in the process of determining whether collection of ileal biopsies is clinically justified. ANIMALS: 40 dogs with chronic small and large intestinal diarrhea from which endoscopic (in 30 cases) or surgical (in 10 cases) duodenal and ileal biopsies had been collected. METHODS: Samples were reviewed concurrently by two observers (MJD and MDW) using the scoring system developed by the World Small Animal Veterinary Association (WSAVA) Gastrointestinal Standardization Group. Comparisons were made by kappa analysis. RESULTS: Microscopic pathology was observed in 30 cases. Only eight out of this 30 (27%) had the same histopathologic diagnosis in both the duodenum and the ileum. This dropped to 3 out of 30 (10%) if different disease severity was also considered as disagreement. Microscopic pathology would have been found in 60% and 80% of the 30 cases, if only duodenal or ileal biopsies respectively, had been available. CONCLUSIONS AND CLINICAL IMPORTANCE: There was poor agreement between histopathological findings from duodenal versus ileal biopsies with abnormalities sometimes being more readily detected in the ileum. Routine collection of ileal plus duodenal samples appears warranted when concurrent small and large intestinal diarrhea is present.

Effect of sample quality on the sensitivity of endoscopic biopsy for detecting gastric and duodenal lesions in dogs and cats.

BACKGROUND: The quality of histopathology slides of endoscopic biopsies from different laboratories varies, but the effect of biopsy quality on outcome is unknown. HYPOTHESIS: The ability to demonstrate a histologic lesion in the stomach or duodenum of a dog or cat is affected by the quality of endoscopic biopsy samples submitted. More endoscopic samples are needed to find a lesion in poor-quality tissue specimens. ANIMALS: Tissues from 99 dogs and 51 cats were examined as clinical cases at 8 veterinary institutions or practices in 5 countries. METHODS: Histopathology slides from sequential cases that underwent endoscopic biopsy were submitted by participating institutions. Quality of the histologic section of tissue (inadequate, marginal, adequate), type of lesion (lymphangiectasia, crypt lesion, villus blunting, cellular infiltrate), and severity of lesion (normal, mild, moderate, severe) were determined. Sensitivity of different quality tissue samples for finding different lesions was determined. RESULTS: Fewer samples were required from dogs for diagnosis as the quality of the sample improved from inadequate to marginal to adequate. Duodenal lesions in cats displayed the same trend except for moderate duodenal infiltrates for which quality of tissue sample made no difference. Gastric lesions in dogs and mild gastric lesions in cats had the same trend, whereas the number of tissue samples needed to diagnose moderately severe gastric lesions in cats was not affected by the quality of tissue sample. CONCLUSIONS AND CLINICAL IMPORTANCE: The quality of endoscopically obtained tissue samples has a profound effect on their sensitivity for identifying certain lesions, and there are differences between biopsies of canine and feline tissues.

Prevalence of gastric lesions in racing Alaskan sled dogs.

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.

Quality of tissue specimens obtained endoscopically from the duodenum of dogs and cats.

OBJECTIVE: To evaluate quality of duodenal tissue specimens obtained endoscopically from dogs and cats and submitted to 1 of 2 diagnostic laboratories for evaluation. DESIGN: Case series. SAMPLE POPULATION: Slides from 50 consecutive canine and 50 consecutive feline endoscopically obtained duodenal tissue specimens submitted to laboratory 1 and 49 consecutive canine and 46 consecutive feline specimens submitted to laboratory 2. PROCEDURE: Slides were examined independently by 3 investigators, and each tissue piece on each slide was classified as clearly inadequate, questionable, or clearly adequate on the basis of 4 criteria. An overall score was then assigned to the slide. RESULTS: Slides from laboratory 1 were more likely to be scored as clearly adequate and less likely to be scored as clearly inadequate than slides from laboratory 2. Clearly adequate slides from laboratory 1 had a higher number of clearly adequate pieces of tissue than did clearly adequate slides from laboratory 2. Slides scored as clearly adequate had a higher number of individual tissue pieces than did slides scored as clearly inadequate. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the quality of endoscopically obtained duodenal tissue specimens submitted to laboratories can vary, possibly because of differences in experience of individuals collecting biopsy specimens. Results suggest that at least 8 individual tissue pieces should be submitted when performing endoscopic biopsy of the duodenum in dogs and cats.

Colonoscopy, proctoscopy, and ileoscopy.

Colonoscopy and proctoscopy are primarily performed on dogs and cats with signs of chronic large bowel or rectal disease, and ileoscopy is typically performed in patients with signs of either large or small bowel disease. These techniques should not be used indiscriminately but only on animals that have a reasonable chance to benefit from their use. Even then, the techniques must be performed carefully so that the results are meaningful instead of misleading. We first consider what does and what does not constitute a reasonable indication for endoscopic examination of the lower intestines. After that, we turn to the specific techniques involved.

Intestinal crypt lesions associated with protein-losing enteropathy in the dog.

Six dogs were diagnosed with protein losing enteropathy (PLE). There was no evidence of inappropriate inflammatory infiltrates or lymphangiectasia in multiple mucosal biopsies of the small intestine of 4 of the dogs. The 5th and 6th dogs had obvious lymphangiectasia and a moderate infiltrate of inflammatory cells in the intestinal mucosa. All 6 dogs had a large number of dilated intestinal crypts that were filled with mucus, sloughed epithelial cells, and/or inflammatory cells. Whether PLE occurs in these dogs because of protein lost from the dilated crypts into the intestinal lumen or whether the dilated crypts are a mucosal reaction due to another undetermined lesion that is responsible for alimentary tract protein loss is unknown. However, when large numbers of dilated intestinal crypts are present, they appear to be associated with PLE even if there are no other remarkable lesions in the intestinal mucosa.

Endoscopic examination of the choanae in dogs and cats: 118 cases (1988-1998).

OBJECTIVE: To determine whether endoscopic examination of the choanae resulted in diagnosis of various diseases in dogs and cats with signs of respiratory tract disease. DESIGN: Retrospective study. ANIMALS: 91 dogs and 27 cats that had endoscopic examination of the choanae. PROCEDURE: Medical records were reviewed for endoscopy findings and results of examination of biopsy or cytologic specimens. RESULTS: 34 animals had neoplasia in the choanal region; in 26 animals, diagnosis was confirmed by evaluation of specimens obtained by endoscopy. Five dogs with neoplasia had an erroneous diagnosis of rhinitis made on the basis of evaluation of specimens obtained by endoscopy. Six dogs and 2 cats had foreign objects in the choanae; 7 foreign objects were removed endoscopically, whereas 1 required nasal flushing. Results of endoscopy and biopsy of the choanae provided diagnosis of cryptococcosis and aspergillosis, but did not aid in the diagnosis of pythiosis or nasal mites. CONCLUSIONS AND CLINICAL RELEVANCE: Endoscopic examination of the choanae may assist in rapid diagnosis of nasal neoplasms, foreign objects, and certain infectious organisms.

Hypercalcemia associated with granulomatous disease in a cat.

A 6-year-old cat was examined because of recurrence of a draining mass involving skin and subcutaneous tissues of the caudoventral aspect of the abdomen. Previous treatment included administration of antimicrobial drugs and corticosteroids and surgical excision. Atypical mycobacteria were seen during cytologic examination of biopsy specimens of the mass; Nocardia sp was cultured. While hospitalized, the cat developed hypercalcemia and was found to have high serum calcitriol concentrations. Treatment consisted of administration of ciprofloxacin and trimethoprim-sulfadiazine because of the infection and administration of sodium chloride solution, furosemide, and calcitonin because of the hypercalcemia. The cat recovered.

Fine-needle aspirate cytology suggesting hepatic lipidosis in four cats with infiltrative hepatic disease.

Four cats are reported in which cytology smears obtained by ultrasound-guided fine needle aspiration of the liver were interpreted as indicative of hepatic lipidosis. However, histopathology of hepatic tissue samples obtained with Tru-Cut-like needles or wedge biopsy revealed that the cats had inflammatory or neoplastic hepatic disease causing their clinical signs. Fine needle aspiration and cytology may not detect infiltrative lesions, particularly those that are nodular, multifocal, or localised around the portal regions. Fine needle aspirate cytology is a useful diagnostic procedure with many advantages, but care must be taken to avoid diagnosing hepatic lipidosis as the cause of illness when an infiltrative lesion is responsible.

Feline inflammatory bowel disease: a review.

Inflammatory bowel disease (IBD), while a popular diagnosis, may not occur as commonly as it is diagnosed. It is a diagnosis of exclusion, meaning that it is important to eliminate diseases that mimick it. Dietary intolerance or allergy in particular, can have the same clinical and histologic appearance as IBD. Likewise, well-differentiated alimentary lymphosarcoma can also be confused with it. Intestinal biopsies are useful, but must be taken carefully and then evaluated by someone with interest and expertise in alimentary tract pathology. Therefore, it behoves the clinician to carefully consider the diagnosis instead of starting multiple drug therapy in a cavalier fashion. Well constructed dietary therapy can often be beneficial for both dietary problems and IBD.

Possible antibiotic-associated colitis in a dog.

A Poodle referred for renal disease developed severe colonic disease characterized by total mucosal collapse and necrosis. The onset of colonic disease was temporally related to administration of antibiotics. On 3 occasions, bacterial culture of fecal samples yielded only Streptococcus pyogenes, Pseudomonas aeruginosa, and Candida albicans, suggesting that the colonic bacterial flora was severely disrupted. Findings, although not conclusive, were suggestive of antibiotic-associated colitis that ultimately proved fatal. Colonoscopy should be considered for dogs with unduly severe large-bowel diarrhea associated with antibiotic treatment and can be done with minimal restraint and bowel preparation, if necessary. Nonselective bacterial culture of fecal samples should be considered for dogs with unduly severe large-bowel diarrhea associated with antibiotic treatment.

Physaloptera infection in 18 dogs with intermittent vomiting.

Physaloptera infections were diagnosed endoscopically in 18 dogs. Each case had vomiting as the primary clinical sign, and four cases had regurgitation as a concurrent sign. Fecal flotations, using magnesium sulfate solution, were performed in 12 of the 18 cases and were negative for Physaloptera eggs. In 12 of the 18 cases, only one worm was seen during endoscopic examination. Fifteen of 18 cases were treated with pyrantel pamoate, and 10 of 12 cases with follow-up had resolution of their vomiting.

Food intolerance mimicking alimentary lymphosarcoma.

A cat with chronic diarrhea was diagnosed as having duodenal lymphosarcoma on two separate sets of endoscopic biopsies. Prednisolone failed to effect any clinical improvement. However, feeding the cat with a hypoallergenic diet resulted in long-term (i.e., six months) resolution of clinical signs. Most clinicians are familiar with the possibility of mistakenly diagnosing inflammatory bowel disease when the patient has lymphosarcoma; however, this case had the opposite problem: lymphosarcoma was diagnosed histologically on two separate occasions when inflammatory bowel disease was the problem.

Presumptive, iatrogenic gastric outflow obstruction associated with prior gastric surgery.

Iatrogenic gastric outflow obstruction in two dogs appeared to be caused by prior gastric surgery. The obstructions were believed to be anatomical rather than functional based on endoscopic examinations. Initially, the dogs had been evaluated and each had received two abdominal surgeries because of gastrointestinal bleeding, vomiting, or both. Eventually, both dogs were euthanized due to complications arising after attempted surgical correction of the iatrogenic obstructions. While gastric surgery commonly is performed, it seldom is considered to be a potentially harmful procedure. However, as these cases demonstrate, the decision to perform a gastrotomy must be weighed against possible risks and complications. Iatrogenic gastric outflow obstruction associated with surgery may be prevented by minimizing tissue inversion into the gastric lumen when surgery is performed near the pyloric outflow tract. Additionally, when large lesions near the pylorus are resected surgically, preservation of the continuity of the outflow tract is necessary.

Third degree atrioventricular block and acquired myasthenia gravis in four dogs.

Third degree atrioventricular block was diagnosed in 4 dogs with acquired myasthenia gravis (serum acetylcholine receptor antibody titer > 0.6 nmol/L). All 4 dogs had megaesophagus. Two dogs also had mediastinal thymomas, which were resected. One dog with thymoma received a permanent pacemaker at the same time that it underwent thymectomy; the other did not develop third degree atrioventricular block until 3 months after thymectomy. Both dogs with thymoma died of severe aspiration pneumonitis within 3 months after surgery. The third dog received a permanent pacemaker and was treated with pyridostigmine bromide, but also died of aspiration pneumonitis 1 month after the pacemaker was implanted. The fourth dog was treated with prednisolone and pyridostigmine bromide and improved, but did not become clinically normal. Because third degree atrioventricular block as well as myasthenia gravis can cause signs of weakness, acquired myasthenia gravis should be considered in dogs with idiopathic cardiac conduction disturbances. Likewise, an ECG should be evaluated in dogs with acquired myasthenia gravis.

Itraconazole for the treatment of histoplasmosis in cats.

Eight cats with histoplasmosis were treated with itraconazole at 5 mg/kg per dose PO bid. There were multiple sites of infection, and 2 of the cats had hypercalcemia that was attributed to the histoplasmosis. All 8 cats were eventually cured, but 2 cats experienced recurrences of disease after completion of therapy, requiring 2 to 3 additional months of itraconazole. There were no clinically relevant adverse effects during treatment. Although a limited number of cats were treated, the study suggests that itraconazole is a well-tolerated and effective drug for the treatment of histoplasmosis in the cat.

Characterization of naturally developing small intestinal bacterial overgrowth in 16 German shepherd dogs.

Sixteen German Shepherd Dogs were found, via quantitative microbial culture of intestinal fluid samples, to have small intestinal bacterial overgrowth (IBO) over an 11-month period. All dogs were deficient in serum IgA. Consistent clinical signs suggestive of an alimentary tract disorder were not observed. Serum cobalamin determinations were not helpful in detecting IBO. Serum folate concentrations had variable sensitivity and specificity for detecting dogs from which we could culture > or = 1 x 10(5) bacterial/ml from intestinal fluid samples in the nonfed state. Histologic and intestinal mucosal cytologic examinations were not useful in detecting IBO. Substantial within-dog and between-dog variation was found in the numbers and species of bacteria in the intestines. The difficulty in diagnosing IBO, the variability in organisms found in individual dogs on repeated sampling, the likelihood that intestinal fluid microbial cultures failed to diagnose IBO in some dogs, and the potential of IBO to be clinically inapparent were the most important findings in this study.