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.     

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 κ statistics determined agreement between pathologists on histologic lesions.
Results: There was poor agreement (κ=−0.013 to 0.3) between pathologists, and institution of origin of slides had effect (κ= 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 κ= 0.69 using 4-point scale versus maximum κ= 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.     

Fluorescence In Situ Hybridization Confirms Clearance of Visible Helicobacter spp. Associated with Gastritis in Dogs and Cats

Background: The results of studies examining the role of Helicobacter spp. in the pathogenesis of canine and feline gastritis are inconclusive. Furthermore, data evaluating the effectiveness of medical therapy for eradication of Helicobacter infection are limited.
Aim: To detect Helicobacter spp. in mucosal biopsies of dogs and cats diagnosed with gastritis, with fluorescence in situ hybridization (FISH).
Animals: Three dogs and 2 cats with signs of chronic gastrointestinal disease.
Methods: Dogs and cats infected with Helicobacter spp. were treated with triple antimicrobial therapy and fed an elimination diet for 21 days. Helicobacter spp. status in endoscopic (3 dogs, 1 cat) or surgical biopsies (1 cat) of gastric mucosa was compared pre- and posttreatment in each animal by histology, FISH analysis, and polymerase chain reaction (PCR).
Results: Gastritis of varying severity with intraglandular spiral bacteria was observed in all animals. Pretreatment diagnostic tests confirmed the presence of mucosal Helicobacter spp. in all animals by FISH and histopathology and in 4/5 animals by PCR. Rapid resolution of vomiting episodes was observed in all animals. Gastric biopsies performed after triple therapy revealed clearance of visible Helicobacter spp. by histopathology and negative FISH analysis, as well as PCR in all animals.
Conclusions and Clinical Importance: Application of FISH to routine biopsy specimens enabled rapid and specific identification of Helicobacter spp. within the gastric mucosa of dogs and cats. Although medical therapy was useful in resolution of clinical signs and clearance of visible Helicobacter spp. in gastric biopsies, gastric inflammation persisted.     

Correlation of ultrasonographic appearance of lesions and cytologic and histologic diagnoses in splenic aspirates from dogs and cats: 32 cases (2002-2005)

OBJECTIVE: To determine the accuracy of cytologic diagnosis, compared with histologic diagnosis, in determination of disease in ultrasound-guided fine-needle aspirates of splenic lesions. DESIGN: Retrospective study. SAMPLE POPULATION: Splenic specimens from 29 dogs and 3 cats. PROCEDURES: Records were searched for dogs and cats that had undergone ultrasound-guided splenic aspiration. Criteria for inclusion were ultrasonographic identification of splenic lesions and cytologic and histologic evaluation of tissue from the same lesion. Cytologic samples were obtained by fine-needle aspiration, and histologic specimens were obtained via surgical biopsy, ultrasound-guided biopsy, or necropsy. RESULTS: Cytologic diagnoses corresponded with histologic diagnoses in 19 of 31 (61.3%) cases and differed in 5 of 31(16.1%) cases, and 1 aspirate was inadequate for evaluation. In 7 of 31 (22.6%) cases, histologic evaluation of tissue architecture was required to distinguish between reactive and neoplastic conditions. On the basis of histologic diagnosis in 14 animals with nonneoplastic conditions, the cytologic diagnosis was correct in 11 cases, not definitive in 2 cases, and incorrect in 1 case. In 17 animals with malignant neoplastic diseases, the cytologic diagnosis was correct in 8 cases, not definitive but consistent with possible neoplasia in 5 cases, and incorrect in 4 cases. Multiple similar-appearing nodules were significantly associated with malignancy, whereas single lesions were more often benign. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided aspiration of splenic lesions is a minimally invasive tool for obtaining specimens for cytologic evaluation. Although cytologic diagnoses often reflect histologic results, if missampling or incomplete sampling occurs or tissue architecture is required to distinguish between reactive and neoplastic conditions, accurate diagnosis with fine-needle aspiration may not be possible.     

Effects of Firocoxib and Tepoxalin on Healing in a Canine Gastric Mucosal Injury Model

Background: Little is known about the effect of dual cyclooxygenase (COX) and lipoxygenase inhibition on canine gastric mucosal healing.
Objective: This study compares the effects of putative dual COX and 5-lipoxygenase inhibition with that of COX-2 selective inhibition on gastric mucosal lesion healing in dogs.
Animals: Six normal adult mixed-breed research dogs.
Methods: Gastric body and pyloric lesions were induced by endoscopic biopsy. Dogs were treated with tepoxalin, firocoxib, or placebo for 7 days in a randomized 3-way crossover study design. Healing was evaluated on days 2, 4, and 7 of treatment by endoscopic lesion scoring. Eicosanoid concentrations in plasma and at the lesion margins were determined on days 2, 4, and 7. Repeated measures analyses were performed. All hypothesis tests were 2-sided with P < .05. Multiple comparisons were adjusted using Tukey's test.
Results: Significant treatment differences were noted in the pyloric lesion area measurements. Overall, the firocoxib group had larger lesions than the placebo ( P = .0469) or tepoxalin ( P = .0089) groups. Despite larger pyloric lesions in the firocoxib group, mucosal prostaglandin production did not differ significantly from placebo. In contrast, the tepoxalin group had significantly lower pyloric mucosal prostaglandin production compared with the firocoxib ( P < .0001) or the placebo ( P < .0001) groups but pyloric lesions were not significantly larger than those of the placebo group ( P = .7829).
Conclusion: COX-2 inhibition by firocoxib slowed wound healing by a mechanism independent of prostaglandin synthesis. Suppression of mucosal prostaglandin production by tepoxalin did not alter mucosal lesion healing compared with placebo.     

ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION BIOPSY OF BONE LESIONS: A PRELIMINARY REPORT

The purpose of this preliminary study was to determine the feasibility of ultrasound-guided fine-needle aspiration biopsy of suspected neoplastic lesions of bone. Ultrasound-guided fine-needle aspiration biopsy samples were obtained in 23 patients (22 dogs and one cat) with radiographic evidence of a destructive or destructive/productive bone lesion. The lesions were located in the appendicular skeleton in 20 patients and in the axial skeleton in three. Histopathology from tissue core biopsies and/or necropsy was not deemed necessary in 11 patients where ultrasound-guided fine-needle aspiration biopsy results were conclusive for neoplasia. A cytologic diagnosis from ultrasound-guided fine-needle aspiration biopsy was confirmed by histologic samples obtained at surgery or necropsy in five patients. In one of these five, ultrasound-guided fine-needle aspiration biopsy samples were diagnostic for sarcoma when tissue-core biopsy was inconclusive. Both ultrasound-guided fine-needle aspiration biopsy and tissue core biopsy techniques were inconclusive in one patient. Ultrasound-guided fine-needle aspiration biopsy samples were nondiagnostic in five patients where a follow-up histopathologic diagnosis of neoplasia was made. It was concluded that ultrasound-guided fine-needle aspiration biopsy of bone, if diagnostic, may help avoid the need for a tissue-core biopsy in some instances. However, a negative ultrasound-guided fine-needle aspiration biopsy sample does not rule out neoplasia. A negative ultrasound-guided fine-needle aspiration biopsy should be followed by a tissue-core biopsy and histologic analysis in all patients. Ultrasound-guided fine-needle aspiration biopsy seems to be a promising technique for the diagnosis of bone lesions.     

ULTRASOUND-GUIDED TISSUE-CORE BIOPSY OF LIVER, SPLEEN AND KIDNEY IN NORMAL DOGS

Six normal dogs were subjected to ultrasound-guided biopsy of the liver, spleen and kidney to examine the accuracy of the technique (i.e. the presence of targeted tissue) and the histologic quality of the biopsies. Five consecutive tissue-core biopsies of each organ were taken on one or more occasions. The accuracy of the technique was 77% for hepatic, 90% for splenic, 53.5% for left kidney and 40% for right kidney biopsies. The histologic quality of the liver and kidney samples was sufficient, although for some samples the diagnostic value was limited by their size and in renal samples either cortical or medullary tissue was sometimes lacking. In contrast, the quality of the splenic sections was not good. The effect of reused and resterilized needles on the quality of the specimens was evaluated by histologic inspection of the samples and by the amount of biopsies lacking tissue. All tissue samples, including those taken with reused or resterilized needles had sharp-cut edges. Twenty-two of the total number of 120 biopsies (18%) contained no tissue. Absence of tissue in the samples was observed in biopsies taken with all needle types. The animals were observed for possible complications of the repeated needle biopsy. Apart from one case of hematuria, no complications were encountered.     

Validation of a transendoscopic glandular and nonglandular gastric biopsy technique in horses

Reasons for performing study: In order to study the evolution of histopathological and immunohistochemical changes in the gastric mucosa of horses with EGUS (equine gastric ulcer syndrome), a feasible, useful, valid and safe in vivo gastric biopsy technique is required. Objectives: To determine the average gastric mucosal healing time following endoscopic gastric biopsy sampling, and evaluate the feasibility, safety and usefulness of samples obtained by this method for histopathological analysis. Methods: Six mature mares from the Faculté de Médecine Vétérinaire research herd were used. Transendoscopic gastric biopsy was performed on Days 0 and 9 using a flexible forceps with oval and fenestrated jaws to obtain gastric mucosal samples from 4 different sites: cardia (C), fundus (F), margo plicatus (MP) and glandular mucosa (GL). A maximum of 4 samples per site was taken and processed routinely for histopathology, evaluated by a pathologist. On Days 1–4 and 9–11 the lesions created by the biopsies were evaluated by gastroscopy. Lesions were evaluated over time based on a score from 0–4, where 4 was the most severe. Results: Biopsy samples could be obtained from all targeted sites except C. No abnormal clinical signs were observed up to 7 days post biopsy. The average biopsy lesion scores decreased significantly with time for all sites. The average lesion score was significantly higher for the MP compared to the other sites at Days 1 and 2. Samples taken from the nonglandular portion of the stomach were considered inadequate for histopathology, while those taken from the glandular mucosa were adequate. Conclusion: The transendoscopic gastric biopsy technique described here is a feasible, safe and useful technique for obtaining samples from the equine gastric glandular mucosa. Although biopsy samples could be obtained from several areas in the nonglandular mucosa, these were very small, took longer to heal and were not considered adequate for histopathological evaluation, and another technique should therefore be validated.     

Histological examination of the intestine from dogs and cats with intussusception

Objectives : To review the histological findings in the intestine from dogs and cats with intussusception. Methods : Medical records and histopathology reports of dogs and cats with intussusception were reviewed retrospectively. Results : Fourty‐nine animals (31 dogs and 18 cats) were identified for inclusion. Tissues examined com‐prised the intussusception alone in 29 animals (16 dogs and 13 cats), and the intussusception with additional intestinal biopsies in 20 animals (15 dogs and 5 cats). Twenty‐eight of 49 (57·1%) animals, comprising 19 of 31 (61·3%) dogs and 9 of 18 cats (50%) had abnormalities detected on histological examination of tissue. Eleven of 29 (46·9%) cases where only the intussusception was submitted achieved a histological diagnosis, compared to 17 of 20 (85%) where additional biopsies were submitted (P=0·003). Cats (median age 36 months, range 2 to 174) were significantly older than dogs (median age 7·5 months, range 1 to 125 months, P=0·010) and were significantly more likely to have underlying neoplasia (5 of 9; 55·6%) compared to dogs who were more likely to have inflammatory causes (17 of 19; 89·5%, P=0·020). There was no association between histological diagnosis and location of the intussusception (P=1·000). Clinical Significance : Histological abnormalities were detected in more than half of the animals. Diagnosis of intestinal disease in animals with intussusception may be improved by submission of additional biopsy samples. Cats with intussusception are more likely to be older and have underlying neoplasia than dogs which are more likely to have inflammatory disease.     

Evaluation of hemorrhage, sample size, and collateral damage for five hepatic biopsy methods in dogs

OBJECTIVES: To compare the volume of hemorrhage, number of lobules, and portal triads available for histologic evaluation, and resultant collateral damage between 5 hepatic biopsy methods: biopsy punch, biopsy needle, ligature method, laparoscopic biopsy forceps, and ultrasonically activated scalpel (UAS). STUDY DESIGN: Experimental, repeated measures, block. ANIMALS: Twelve adult dogs. METHODS: Biopsies were obtained from the periphery and center of the left lateral liver lobe of each dog using each of 5 biopsy techniques. Hemorrhage was quantified and compared between methods and sites. Biopsy samples were evaluated histologically to characterize collateral damage and determine the number of lobules and portal triads sampled. RESULTS: Regardless of technique, liver biopsy resulted in minimal hemorrhage (<2 mL). For peripheral biopsies, UAS was comparable with the ligature method, but caused significantly less hemorrhage than all other methods, whereas for central biopsies, UAS caused significantly less hemorrhage than other methods. Except for the laparoscopic biopsy forceps, UAS caused significantly more collateral damage than other methods. UAS and ligature biopsy methods yielded specimens that had more portal triads per sample than other methods. Eight of 48 biopsy needle samples were inadequate for histologic evaluation, whereas other methods yielded adequate specimens. CONCLUSIONS: All biopsy methods produced minimal hemorrhage and except for needle biopsy yielded adequate tissue samples for histologic evaluation. CLINICAL RELEVANCE: Use of UAS is a reliable, safe alternative technique for liver biopsy and can be used laparoscopically to obtain large tissue samples.     

Fecal polymerase chain reaction with 16S ribosomal RNA primers can detect the presence of gastrointestinal Helicobacter in dogs

Questions about pathogenesis and therapy for Helicobacter infections in dogs could be answered with a simple, noninvasive, sensitive, and specific diagnostic test. We hypothesized that a fecal polymerase chain reaction (PCR) assay would detect Helicobacter and could be useful for assessing therapeutic responses. Paired gastric biopsies and fecal samples were obtained from 39 random source dogs (group 1). Gastric biopsies from each of these dogs had histologic evidence of gastric spiral bacteria, and paired gastric tissue and fecal samples produced a 375-base pair (bp) product when amplified by PCR with Helicobacter-specific primers. Specificity of the PCR product was confirmed by detection of expected 60-, 119-, and 196-bp products following Hinfl digestion. Direct sequencing of amplicons from paired PCR products from gastric biopsy and fecal samples from 8 group I dogs showed that gastric products had the highest homologies with known gastric Helicobacter species, whereas fecal products had the highest homologies with intestinal species. Healthy mixed-breed dogs (group II; n = 8) with histologically confirmed spiral bacteria infection were treated with a 21-day course of metronidazole, amoxicillin, and famotidine. Fecal samples were collected from group II dogs twice before and within 3 days of completion of treatment. The PCR results correctly identified 15/16 pretreatment samples as positive: 1 pretreatment sample was negative. PCR results identified 8/8 posttreatment samples as Helicobacter negative. Fecal PCR is a useful test for detecting Helicobacter infection in dogs. This assay may be useful as a screening test for infection and could be used to address questions relevant to pathogenesis and therapy.     

Squash-prep cytology in the diagnosis of canine and feline nervous system lesions: a study of 42 cases

BACKGROUND: The increased sophistication of imaging techniques in veterinary medicine allows the detection of a wide variety of intracranial and intraspinal lesions; however, imaging often does not provide a definitive diagnosis for nervous system (NS) lesions. Cytology is emerging as a useful diagnostic tool for obtaining a fast and accurate assessment of NS lesions, but little information is available for dogs and cats. OBJECTIVES: The purpose of this study was to assess the accuracy of cytologic evaluation of squash samples from NS lesions in dogs and cats and to consider cytology-based diagnostic guidelines and sources of misdiagnosis. METHODS: Cytologic specimens from masses localized in the central and peripheral NS taken during surgery or postmortem examination were classified into 3 groups according to the final histopathologic diagnosis: Group 1 = completely correct diagnosis, when the cytologic diagnosis and final histologic diagnosis were exactly correlated; Group 2 = partial correlation, when the cytologic diagnosis only partially correlated with the final histologic diagnosis, and Group 3 = no correlation, when the cytologic diagnosis was incorrect and there was no correlation with the general histologic type of lesion. The diagnostic accuracy of cytopathology was calculated by considering the histopathologic diagnosis as the "gold standard," and calculating a 95% confidence interval (CI). RESULTS: A total of 42 animals (33 dogs and 9 cats) were included in the study. The cytologic diagnoses were classified in Group 1 for 32 cases (76%; 95% CI 0.63-0.89), in Group 2 for 6 cases (14%; 95% CI 0.04-0.25), and in Group 3 for 4 cases (10%; 95% CI 0.006-0.18). Considering both complete and partial correlation as an adequate result, cytologic diagnosis was satisfactory in 90% of biopsies. CONCLUSIONS: Although the current series of cases is relatively small, cytologic evaluation of squash preparations can be considered a fairly accurate and reliable tool in the diagnosis of NS lesions.     

Renal biopsy: a retrospective study of methods and complications in 283 dogs and 65 cats

Renal biopsy often is required to establish a definitive diagnosis in dogs and cats with renal disease. In this retrospective study, we determined the complications of renal biopsy as well as factors that may be associated with development of complications and procurement of adequate renal biopsy specimens in 283 dogs and 65 cats. Data extracted from medical records at 4 institutions were evaluated using logistic regression. Proteinuria was the most common indication for renal biopsy in dogs. Complications were reported in 13.4 and 18.5% of dogs and cats, respectively. The most common complication was severe hemorrhage; hydronephrosis and death were uncommon. Dogs that developed complications after renal biopsy were more likely to have been 4 to < 7 years of age and > 9 years, to weigh < or = 5 kg, and to have serum creatinine concentrations > 5 mg/dL. The majority of biopsies from both dogs (87.6%) and cats (86.2%) were considered to be of satisfactory quality. Biopsies from dogs were more likely to be of high quality if they were obtained when the patient was under general anesthesia and more likely to contain only renal cortex if they were obtained by surgery. We concluded that renal biopsy is a relatively safe procedure, with a low frequency of severe complications. Hospital practices and patient variables have the potential to impact both the quality of the specimen obtained and the rate of complications.     

Ultrasound-guided serial transabdominal cardiac biopsies in cats

A percutaneous/transdiaphragmatic core needle biopsy technique was developed in cats to obtain serial biopsies from different locations of the left ventricle, through which morphological and molecular changes within the same individual can be studied to unravel the mechanisms of feline cardiomyopathies. Transmural left ventricular myocardial samples were obtained from 29 anesthetized, healthy, adult cats with ultrasound guidance. An 18G automatic biopsy needle was inserted between the last left rib and the sternum through the diaphragm into the thorax. Biopsies were obtained from the left ventricular wall. In five cats, three single biopsies were taken with 4-week intervals. Autopsy was performed on six cats, of which three cats had serial biopsies. In total, 87 biopsies were obtained without long-term effects on cardiac function or structure. The biopsies caused transient single ventricular premature complexes and mild pericardial effusion without tamponade. Necropsy revealed a minimal amount of fibrous connective tissue in the diaphragm and the heart without any significant microscopic lesions in the adjacent muscle tissue. The high quality biopsy material was suitable for morphological and molecular studies. This minimally invasive, ultrasound-guided cardiac biopsy technique thus allows for the safe collection of serial biopsies to study feline cardiomyopathies in an experimental setting.     

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.     

Idiopathic inflammatory bowel disease in dogs and cats: 84 cases (1987-1990).

Idiopathic inflammatory bowel disease was the diagnosis for 58 dogs and 26 cats, with signs of persistent gastroenteritis, failed responses to dietary trials, and histologic evidence of cellular infiltrates unrelated to other causes of gastrointestinal tract inflammation. Clinical signs of large intestinal dysfunction, watery diarrhea, vomiting, and anorexia with weight loss were common. Nonspecific hematologic, biochemical, and radiographic abnormalities frequently were observed. Mucosal biopsy specimens, obtained endoscopically, were histologically evaluated for severity of mucosal epithelial damage. Mucosal erythema, friability, enhanced granularity, and ulceration or erosion were the predominant endoscopic lesions. Inflammatory bowel disease lesions of moderate severity predominated in the stomach, duodenum, and colon. Lymphocytic/plasmacytic infiltrates were limited to the lamina propria in biopsy specimens from all regions of the gastrointestinal tract. Inflammatory bowel disease commonly is associated with chronic gastroenteritis in dogs and cats.     

Use of thoracoscopy to determine the etiology of pleural effusion in dogs and cats: 18 cases (1998-2001)

OBJECTIVE: To assess use of thoracoscopy to determine causes of pleural effusion in dogs and cats. DESIGN: Retrospective study. ANIMALS: 15 dogs and 3 cats with pleural effusion. PROCEDURE: Medical records were reviewed from 1998 to 2001 for dogs and cats that had exploratory thoracoscopy, biopsy, and histologic analysis to determine the etiology of pleural effusion. Intraoperative and postoperative complications were recorded. Surgical biopsy specimens were evaluated for quantity and quality for providing a histologic diagnosis. RESULTS: Biopsy specimens were deemed adequate in quantity and quality to render a histologic diagnosis in all animals. Etiology of the effusion was neoplasia in 8 animals and non-neoplastic pleuritis in 10 animals. Median survival time of animals with neoplasia was 15 days, whereas those with inflammatory diseases had median survival time of > 785 days. Postoperative pneumothorax was encountered in 2 animals subsequent to pulmonary biopsy. No other major complications were recorded. CONCLUSIONS AND CLINICAL RELEVANCE: Thoracoscopy is a diagnostic option that provides excellent viewing of intrathoracic structures and adequate biopsy specimens with minimal complications. This technique provides a less invasive alternative to thoracotomy for evaluating the etiology of pleural effusion.     

Use of keyhole lung biopsy for diagnosis of interstitial lung diseases in dogs and cats: 13 cases (1998-2001)

OBJECTIVE: To characterize interstitial lung diseases (ILDs) and evaluate use of keyhole lung biopsy for diagnosis of ILDs in dogs and cats. DESIGN: Retrospective study. ANIMALS: 11 dogs and 2 cats. PROCEDURE: Medical records of dogs and cats undergoing keyhole lung biopsy to confirm ILDs were reviewed. Signalment, clinical signs, results of thoracic radiography and other respiratory diagnostic tests, postoperative complications, and patient outcome were analyzed. RESULTS: Clinical respiratory signs included cough, tachypnea, exercise intolerance, and hemoptysis. Thoracic radiographic abnormalities included interstitial, alveolar, and bronchointerstitial patterns and multiple discrete pulmonary nodules. Lung biopsy and histologic examination revealed interstitial pulmonary fibrosis, bronchiolitis obliterans with organizing pneumonia, or unclassified lesions. Outcome after biopsy included no response to treatment, euthanasia, partial or complete remission while receiving medication, and cure. CONCLUSIONS AND CLINICAL RELEVANCE: Recognition and classification of ILDs in dogs and cats are likely to be important in guiding appropriate treatment and providing accurate prognostic information. Ancillary respiratory diagnostic tests are beneficial in ruling out infectious and neoplastic disorders that may mimic ILDs; however, their present use in the diagnosis of ILDs is limited. Results suggest that keyhole lung biopsy is an effective means for obtaining a specimen for histologic diagnosis in dogs and cats with ILDs.