Magnetic Resonance Imaging Characteristics of Necrotizing Meningoencephalitis in Pug Dogs

Background: The magnetic resonance imaging (MRI) characteristics of necrotizing meningoencephalitis (NME) are not well documented.
Objectives: To describe common MRI features of NME, to compare the MRI features to histopathologic findings, and to determine whether or not MRI lesions are predictive of survival time.
Animals: Eighteen Pugs with NME.
Methods: Retrospective MRI case study of Pugs identified by a search of medical records at 6 veterinary institutions. Eighteen dogs met inclusion criteria of histopathologically confirmed NME and antemortem MRI exam. MRI lesions were characterized and compared with histopathology with the kappa statistic. Survival times were compared with MRI findings by use of Mann-Whitney U -tests and Spearman's ρ.
Results: Twelve of 18 lesions were indistinctly marginated with mild parenchymal contrast enhancement. Prosencephalic (17/18) lesion distribution included the parietal (16/18), temporal (16/18), and occipital (16/18) lobes. There were cerebellar (4/18) and brainstem (3/18) lesions. Asymmetric lesions were present in both gray and white matter in all dogs. Falx cerebri shift was common (11/18), and 6 dogs had brain herniation. Leptomeningeal enhancement was present in 9/18 dogs. A moderate positive association was found between parenchymal contrast enhancement and both necrosis (κ= 0.45; P = .045) and monocytic inflammation (κ= 0.48; P = .025). Higher MRI lesion burden was correlated with longer time from disease onset to MRI ( P = .045). MRI lesion burden did not correlate to survival time.
Conclusions and Clinical Importance: Asymmetric prosencephalic grey and white matter lesions with variable contrast enhancement were consistent MRI changes in Pugs with confirmed NME. While not pathognomonic for NME, these MRI characteristics should increase confidence in a presumptive diagnosis of NME in young Pugs with acute signs of neurologic disease.     

Risk Factors for Equine Postoperative Ileus and Effectiveness of Prophylactic Lidocaine

Background: Postoperative ileus (POI) is a frequent and often fatal complication of colic surgery. Reliably effective treatments are not available.
Objectives: To determine risk factors and protective factors associated with POI, and to assess the effect of lidocaine IV on short-term survival.
Animals: One hundred and twenty-six horses that underwent small intestinal colic surgery and that survived for at least 24 hours postoperatively.
Methods: Retrospective cross-sectional study. The association of 31 pre-, intra-, and postoperative variables with POI and the association of lidocaine treatment with short-term survival were investigated. Associations were evaluated with univariable logistic regression models, followed by multivariable analysis.
Results: Significant associations of high heart rate (odds ratio [OR] = 1.05, 95% confidence interval [CI] 1.03–1.08), the presence of more than 8 L of reflux at admission (OR = 3.02, 95% CI 1.13–8.02) and the performance of a small intestinal resection (OR = 2.46, 95% CI 1.15–5.27) with an increased probability of POI were demonstrated. Prophylactic lidocaine treatment was significantly associated with a reduced incidence of POI (OR = 0.25, 95% CI 0.11–0.56). Lidocaine treatment was also significantly associated with enhanced short-term survival (OR = 0.30, 95% CI 0.09–0.98).
Conclusions and Clinical Importance: The variables associated with an increased risk of POI can be useful in identifying horses at risk of POI and in providing a more accurate prognosis. The results are supportive for lidocaine IV as an effective prokinetic treatment after small intestinal colic surgery.     

FC-50 Results of repeat intradermal testing in 135 dogs

Objective assessment of canine atopic dermatitis severity is very difficult and only a few scoring systems have been developed. The most commonly used is the Canine Atopic Dermatitis Extent and Severity Scoring Index (CADESI), adapted from the human SCORAD. Despite wide use of this score in clinical trials, no validation has been performed to our knowledge. The aim of this study was to determine the reliability of the CADESI in clinical practice. First, a set of 28 pictures taken from dogs diagnosed with atopic dermatitis was scored by six different investigators for three items: erythema, lichenification and excoriation. Next, 23 dogs with clinical signs compatible with atopic dermatitis were graded by two investigators using the CADESI. Erythema, lichenification and excoriation were assessed on 39 areas. With the pictures, significant correlations (Spearman's r , P  < 0.05) were found for each combination of investigators for erythema and lichenification, but only in 10 of 15 combinations for excoriation. Interobserver agreement ranged between poor and fair (0.221 < Cohen's κ <0.508, mean = 0.395). For the living animals, significant correlations ( P  < 0.0001), but poor interobserver agreement, were found for the three items (κ_erythema = 0.366, κ_{lichenification} = 0.385, and κ_excoration = 0.226). A significant correlation ( P  < 0.05) was found for each location, and interobserver agreement varied between very poor and good (0.16 < κ < 0.66). These results suggest that erythema and lichenification are reliably assessed, but that grading excoriation is more difficult. Also, the assessment of severity varied depending on the site studied.
Funding: Self-funded.     

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.     

Clinical, clinicopathologic, radiographic, and ultrasonographic characteristics of intestinal lymphangiectasia in dogs: 17 cases (1996-1998)

OBJECTIVE: To characterize the clinical, clinicopathologic, and imaging findings in dogs with intestinal lymphangiectasia and to compare the histologic grade of lymphangiectasia with clinicopathologic and imaging abnormalities. DESIGN: Retrospective study. ANIMALS: 17 dogs with a histologic diagnosis of intestinal lymphangiectasia. PROCEDURE: Medical records of dogs with a histologic diagnosis of intestinal lymphangiectasia were reviewed for signalment, history, clinical signs, results of exploratory laparotomy, and clinicopathologic, radiographic, ultrasonographic, and histologic findings. RESULTS: Mean age of dogs was 8.3 years; the most common clinical signs were diarrhea, anorexia, lethargy, vomiting, and weight loss. Abnormal physical examination findings included dehydration, ascites, and signs of pain on palpation of the abdomen. The most notable clinicopathologic findings were low serum ionized calcium concentration and hypoalbuminemia. Abdominal ultrasonography was performed in 12 dogs and revealed intestinal abnormalities in 8 dogs and peritoneal effusion in 7 dogs. Exploratory laparotomy revealed abnormalities in 9 of 16 dogs including thickened small intestine, dilated lacteals, lymphadenopathy, and adhesions. On histologic examination of the small intestine, concurrent inflammation was observed in 15 of 17 dogs, crypt ectasia in 5 of 17, and lipogranulomas in 2 of 17. CONCLUSIONS AND CLINICAL RELEVANCE: Intestinal lymphangiectasia in dogs appears to be a heterogeneous disorder characterized by various degrees of panhypoproteinemia, hypocholesterolemia, lymphocytopenia, and imaging abnormalities. In most dogs, the severity of hypoalbuminemia appears to offer the best correlation with severity of histologic lesions of lymphangiectasia. Imaging abnormalities are common in dogs with intestinal lymphangiectasia but are not specific enough to differentiate this disorder from other gastrointestinal disorders, nor are they predictive of histologic severity.     

Evaluation of an abdominal fluid scoring system determined using abdominal focused assessment with sonography for trauma in 101 dogs with motor vehicle trauma

Objective – Evaluate an abdominal fluid scoring (AFS) system using an abdominal focused assessment with sonography for trauma (AFAST) protocol.
Design – Prospective study.
Setting – Private veterinary emergency center.
Animals – One hundred and one client-owned dogs with motor vehicle trauma.
Interventions – AFAST performed on admission and 4 hours post-admission.
Measurements and Main Results – An AFS was assigned to each dog based on the number of AFAST fluid-positive quadrants identified using a 4-point scale: AFS 0 (negative for fluid in all quadrants) to AFS 4 (positive for fluid in all quadrants). Free abdominal fluid was identified in 27 of 101 dogs (27%). Dogs with AFS scores of 3 or 4 (14/27 [52%] AFS-positive dogs) experienced more marked decreases in packed cell volume and total plasma protein, increases in alanine aminotransferase, and needed more blood transfusions than dogs with lower AFS scores and AFS-negative dogs. Serial AFAST was performed in 71% of dogs (71/101); 17% (12/71) of these cases changed AFS score, and 75% (9/12) of the changes were higher (worsened) AFS, correlating with increasing amounts of free abdominal fluid. Ninety-eight percent of the study population was a primary presentation. Overall, median time from trauma to initial AFAST was 60 minutes, and median AFAST examination time was 3 minutes.
Conclusions – Initial and serial AFAST with applied AFS allowed rapid, semiquantitative measure of free abdominal fluid in traumatized patients, was clinically associated with severity of injury, and reliably guided clinical management. Where possible, AFAST and AFS should be applied to the management of blunt trauma cases.     

Magnetic resonance imaging characterization of canine splenic lesions

Introduction:  Splenic lesions are a common finding in veterinary medicine and typically 1/2 to 2/3 of these lesions are malignant. Due to the limited accuracy of ultrasound, unnecessary exploratory surgeries/biopsies may be performed for benign lesions and treatment may be delayed for malignant ones. Splenic lesions are rare in people. MR imaging, with its inherently high soft tissue contrast, is efficacious in imaging the human spleen. We have previously demonstrated the efficacy of MRI to differentiate canine hepatic lesions. In that study 8 splenic lesions were all accurately characterized. This current study represents a further evaluation of splenic lesions.
Methods:  In this prospective study, 27 dogs with splenic lesions were accrued. Histopathological/cytological confirmation of lesions occurred either before or shortly after imaging. MRI clinicians were blinded to histopathology results. MR (General Electric, 1.5 Tesla) images using a variety of sequences were obtained before and after intravenous administration of gadolinium.
Results:  32 lesions (9 malignant, 23 benign) were evaluated in 27 dogs. Lesions were confirmed via histopathology (n = 20) or cytology (n = 12). Benign lesions included, EMH (n = 7), hematoma/hemorrhage (n = 5), lymphoid hyperplasia (n = 9), and hemangioma (n = 2). Malignant lesions included anaplastic sarcoma (n = 3), malignant histiocytosis (n = 2), hemangiosarcoma (n = 2), plasma cell tumor (n = 1) and adenocarcinoma (n = 1). The overall accuracy in differentiating benign from malignant lesions was 88%(29/32 lesions). The overall sensitivity and specificity were 100%(95% CI, 66–100) and 87%(95% CI 66–97).
Conclusions:  Based upon these results, MRI is both sensitive and specific in distinguishing between malignant and benign splenic lesions.     

Temporal Variability of Ventricular Arrhythmias in Boxer Dogs with Arrhythmogenic Right Ventricular Cardiomyopathy

Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is prevalent in the Boxer. There is little information on the temporal variability of ventricular arrhythmias within affected dogs.
Objective: To evaluate ambulatory electrocardiograms (AECG) from Boxers with ARVC for hourly variation in premature ventricular complexes (PVC) and heart rate (HR).
Animals: One hundred and sixty-two Boxer dogs with ARVC.
Methods: Retrospective, observational study of 1,181 AECGs collected from Boxer dogs at The Ohio State University from 1997 to 2004 was evaluated. The proportion of depolarizations that were PVCs was compared across each hour of the day, during six 4-hour periods of day, to the time after AECG application, and to the maximum and minimum HR.
Results: A lower proportion of PVCs was noted during early morning (midnight to 0400 hours) as compared with the morning (0800–1200 hours) and late (1600–2000 hours) afternoon ( P = .012). There was no increase in PVC proportion in the 1st hour after AECG application as compared with all other hours of the day ( P = .06). There was poor correlation between maximum (ρ= 0.19) and minimum (ρ= 0.12) HR and PVC proportion.
Conclusions and Clinical Importance: The likelihood of PVC occurrence in Boxer dogs with ARVC was relatively constant throughout the day, although slightly greater during the hours of 0800–1200 and 1600–2000. A biologically important correlation with HR was not apparent. The role of autonomic activity in the modulation of electrical instability in the Boxer with ARVC requires further study.     

Agreement in histologic assessments of the pituitary pars intermedia in aged horses

OBJECTIVE: To evaluate concordance among veterinary pathologists in the assessment of histologic findings in the pars intermedia of pituitary gland sections from aged horses with mild signs suggestive of pituitary pars intermedia dysfunction (PPID). Sample Population-10 pituitary glands from aged horses. PROCEDURE: 7 pathologists were provided with signalment, clinical signs, and a single H&E-stained pituitary gland section from 10 aged horses with mild signs suggestive of PPID. Pathologists described histologic findings for each section and stated whether findings were consistent with PPID. Agreement among pathologists and with antemortem diagnostic test results was calculated. RESULTS: Overall, only fair agreement was found among the pathologists as to which horses had histologic findings consistent with disease (mean +/- SE kappa value, 0.34 +/- 0.069). Interpretation of individual sections varied, with minimal agreement (4 or 5/7 pathologists) for 5 of 10 sections evaluated. Postmortem assessment was in agreement with an antemortem endocrine diagnostic test result 79% of the time. CONCLUSIONS AND CLINICAL RELEVANCE: Validation of antemortem diagnostic testing for PPID in horses often relies on the results of postmortem histologic evaluation. The lack of consensus in histologic interpretation of pituitary glands from aged horses with mild clinical signs in our study indicates that postmortem histologic evaluation of pituitary glands is an inappropriate standard in validation of antemortem diagnostic tests for detection of early PPID. Caution should be used when interpreting diagnostic test results in horses in which early PPID is suspected.     

Prevalence of malignancy when solitary versus multiple lesions are detected during abdominal ultrasonographic examination of dogs with spontaneous hemoperitoneum: 31 cases (2003–2008)

Objective – To compare the histopathologic diagnosis in dogs with spontaneous hemoperitoneum when abdominal ultrasonographic examination detects a solitary versus multiple lesions.
Design – Retrospective cross-sectional study.
Setting – Private veterinary hospital.
Animals – Client-owned dogs presented with spontaneous hemoperitoneum between March 1, 2003 and June 1, 2008.
Interventions – Dogs were divided into 2 groups based on presence of a solitary or multiple abdominal ultrasonographic lesions. Prevalences were compared between groups for malignancy and specifically hemangiosarcoma.
Measurements and Main Results – Ten of 31 (32%) dogs had a solitary abdominal ultrasonographic lesion and 21 of 31 (68%) had more than 1 lesion. The bleeding tissue was characterized as malignant in 8 of 10 (80%) dogs with solitary lesions and 17 of 21 (81%) dogs with multiple lesions; there was no significant difference ( P =1.0) between groups. In this study no association ( P =0.26) was found between the number of abdominal ultrasonographic lesions observed and subsequent diagnosis of hemangiosarcoma.
Conclusions – Solitary abdominal ultrasonographic lesions in dogs with spontaneous hemoperitoneum do not necessarily indicate a lower prevalence of malignancy.     

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.     

Contrast harmonic imaging characterization of canine splenic lesions

Background: Although B-mode ultrasound is very sensitive for the detection of splenic lesions, its specificity is low. Contrast harmonic imaging is used successfully to differentiate benign from malignant liver lesions in humans and dogs.
Hypothesis: Contrast harmonic imaging could be useful to differentiate benign and malignant splenic lesions in dogs.
Animals: Sixty dogs (clinical patients) with splenic abnormalities detected during abdominal ultrasonography.
Methods: A prospective study was performed with a Philips ATL 5000 unit for contrast pulse inversion harmonic imaging (mechanical index: 0.08, contrast medium: SonoVue). Perfusion was assessed subjectively and quantitatively.
Results: Cytology or histology identified 27 benign (hyperplasia, extramedullary hematopoiesis, hematoma) and 29 malignant (hemangiosarcoma, malignant lymphoma, malignant histiocytosis, mesenchymal tumors without classification, mast cell tumors, and others) lesions and 4 normal spleens. Except for 1 benign nodule, extensive to moderate hypoechogenicity was only seen in malignant lesions during wash-in, at peak enhancement, and during wash-out ( P = .0001, odds ratios: 37.9 [95% CI 4.5–316.5], 66.4 [95% CI 8.0–551.1], and 36.9 [95% CI 4.4–308.4]). Although all but 1 benign lesion enhanced well and were mildly hypo-, iso-, or hyperechoic in comparison with the normal spleen during all blood pool phases, marked enhancement occurred both in benign as well as in malignant splenic lesions. Quantitative perfusion values did not differ significantly between benign and malignant lesions.
Conclusions and Clinical Importance: Moderate to extensive hypoechogenicity clearly identifies canine splenic malignant lesions. In nodules with marked enhancement, contrast harmonic ultrasound is of limited value and histology is needed.     

Cytomorphologic differentiation of benign and malignant mammary tumors in fine needle aspirate specimens from irradiated female Sprague–Dawley rats

Background: Fine needle aspiration (FNA) offers a rapid and minimally invasive means to distinguish malignant from benign neoplasms. However, few studies have been published regarding the cytopathology of mammary tumors in rats despite widespread use of the rat model for breast cancer formation and inhibition.
Objective: The purpose of this study was to determine the diagnostic accuracy of FNA cytology and to develop distinguishing cytologic criteria for the diagnosis of radiation-induced benign and malignant mammary tumors in rats.
Methods: In a study of radiation-induced mammary carcinogenesis, 100 Sprague–Dawley rats with cutaneous masses were randomly chosen for FNA. The aspirates were smeared, fixed, and stained with a modified Papanicolaou procedure for diagnostic evaluation. Cytologic and histologic diagnoses (benign vs malignant) were compared, and diagnostic accuracy was calculated using the histologic diagnosis as the criterion standard. FNA smears were scored semiquantitatively on a scale of 1–4 for cellularity, atypia, nuclear size, chromatin pattern, nuclear membrane thickness, nucleoli, and mitoses. The background was evaluated for necrosis, hemorrhage, inflammation, and mucosecretory material. Cytomorphologic features were compared statistically between benign and malignant tumors, based on the histologic diagnosis.
Results: The sensitivity of FNA was 92.3% and specificity was 89.4% for the detection of malignancy. However, 14% of specimens, all fibroadenomas by histology, had insufficient cells for cytologic evaluation, for an overall accuracy rate of 78.0%. Malignant tumors had significantly higher scores for all cytomorphologic features, and were significantly more likely to contain cell clusters and necrotic debris.
Conclusions: FNA is an accurate method for differentiating benign and malignant rat mammary tumors.     

P-9 CD8 and CD4 lymphocyte populations in blood from healthy dogs and dogs naturally infected with Ehrlichia canis

The purpose of this study was to determine whether doxycycline (Ronaxan) decreased the severity of localized lesions of canine acne. Dogs were enrolled if they exhibited skin lesions localized to the chin compatible with canine acne, and if cytological smears showed a bacterial invasion and bacteriological samples grew Staphylococcus intermedius colonies. Demodicosis and dermatophytosis were excluded by skin scrapings and fungal culture, respectively. Lesions (erythema, lichenification, papules, pustules and excoriations) were graded with a quantitative 4-point scale (maximal total score 15). Extent of lesion was also estimated. Pruritus was graded on a 4-point scale. Scores were given at the time of inclusion and at day 30 after treatment with doxycycline 10 mg/kg once daily. Twelve dogs (10 males and two females) representing seven breeds were included. Good improvement of both lesional (9.4 before treatment and 2.3 after treatment) and extent scores (43% before treatment and 8% after treatment) was achieved. Pruritus was also markedly improved from 2.08 before treatment to 0.42 after treatment. One dog was not significantly improved after 1 month. Results of this trial suggest that doxycyline is useful for reducing the severity of localized skin lesions of canine acne.
Funding: Self-funded.     

Infectious Agents Detected in the Feces of Diarrheic Foals: A Retrospective Study of 233 Cases (2003–2008)

Background: Diarrhea is common in foals but there are no studies investigating the relative prevalence of common infectious agents in a population of hospitalized diarrheic foals.
Objectives: To determine the frequency of detection of infectious agents in a population of hospitalized foals with diarrhea and to determine if detection of specific pathogens is associated with age, outcome, or clinicopathologic data.
Animals: Two hundred and thirty-three foals ≤ 10 months of age with diarrhea examined at a referral institution.
Methods: Retrospective case series. Each foal was examined for Salmonella spp., viruses, Clostridium difficile toxins, Clostridium perfringens culture, C. perfringens enterotoxin, Cryptosporidium spp., and metazoan parasites in feces collected at admission or at the onset of diarrhea.
Results: At least 1 infectious agent was detected in 122 foals (55%). Rotavirus was most frequently detected (20%) followed by C. perfringens (18%), Salmonella spp. (12%), and C. difficile (5%). Foals < 1 month of age were significantly more likely to be positive for C. perfringens (odds ratio [OR] = 15, 95% confidence interval [CI] = 3.5–66) or to have negative fecal diagnostic results (OR = 3.0, 95% CI = 1.7–5.2) than older foals. Foals > 1 month of age were significantly more likely to have Salmonella spp. (OR = 2.6, 95% CI = 1.2–6.0), rotavirus (OR = 13.3, 95% CI = 5.3–33), and parasites (OR = 23, 95% CI = 3.1–185) detected compared with younger foals. Overall 191 of the 223 foals (87%) survived. The type of infectious agent identified in the feces or bacteremia was not significantly associated with survival.
Conclusions and Clinical Importance: In the population studied, foals with diarrhea had a good prognosis regardless of which infectious agent was identified in the feces.     

Comparison of Histopathologic Findings in Duodenal and Ileal Endoscopic Biopsies in Dogs with Chronic Small Intestinal Enteropathies

Background

The current tendency when investigating dogs with chronic upper gastrointestinal signs is to perform endoscopy and biopsy only the duodenum. This approach could lead to overlooking important ileal lesions and affect the clinical management.

Objectives

To compare concurrent duodenal and ileal endoscopic biopsies in dogs with chronic enteropathies and evaluate their correlation with clinicopathologic findings.

Animals

Thirty‐eight dogs with chronic enteropathies.

Methods

Duodenal and ileal biopsies were retrospectively reviewed. Nine histologic variables, 5 structural (villous stunting, epithelial injury, crypt distension, lacteal dilatation, and mucosal fibrosis) and 4 inflammatory (intraepithelial lymphocytes, lamina propria lymphocytes and plasma cells, eosinophils, and neutrophils) were scored. Clinical severity scores and relevant clinicopathologic variables were evaluated.

Results

There was only slight agreement between duodenal and ileal histologic scores (κ = 0.003). There was slight agreement between the presence of any of the morphological and inflammatory variables, with the exception of mucosal fibrosis (κ = 0.44). Statistically significant correlation was found between clinical severity and duodenal crypt distension (P = .031), ileal lacteal dilatation (P = .038), and ileal mucosal lymphoplasmacytic inflammation (P = .035). A significant correlation was found between hypoalbuminemia and ileal lacteal dilatation (P = .033) and number of ileal intraepithelial lymphocytes (P = .019). A statistically significant correlation was found between hypocobalaminemia and number of ileal intraepithelial lymphocytes (P = .012).

Conclusions and Clinical Importance

When investigating dogs with chronic upper gastrointestinal signs, the collection of concurrent duodenal and ileal endoscopic biopsies is recommended.     

Reclassification of small intestinal and cecal smooth muscle tumors in 72 dogs: clinical, histologic, and immunohistochemical evaluation

Objectives— To reclassify canine small intestinal and cecal leiomyoma (LM) and leiomyosarcoma (LMS) into smooth muscle and gastrointestinal stromal tumors (GIST) using histologic and immunohistochemical (IH) analysis and to report clinical findings and survival data.
Study Design— Retrospective review of cases.
Animals— Dogs (n=47) with small intestinal (40 LMS; 7 LM) and 25 dogs with cecal tumors (23 LMS; 2 LM).
Methods— Clinical and survival data were reviewed. Tissue sections were reevaluated for light-microscopic malignancy criteria and examined for expression of SMA, desmin, vimentin, S-100, and CD117 (KIT) by immunohistochemistry.
Results— Reclassification resulted in 2 LM, 9 LMS, 19 GIST, and 17 GIST-like tumors in the small intestine and 23 GIST and 2 GIST-like tumors in the cecum. GIST-like tumors were morphologic and IH identical to GIST but lacked KIT expression. No significant difference in survival was observed for tumor type, location, histologic, or IH characteristics; however, dogs with cecal tumors were significantly older in age, presented more commonly with intestinal perforation and peritonitis, and less commonly with weight loss. Cecal tumors had more histologic malignancy criteria than small intestinal tumors. After excision, 1 and 2 year recurrence-free periods were 80.1% and 67.2% for small intestinal and 83.3% and 61.9% for cecal tumors.
Conclusion— Prognosis for intestinal tumors with histologic smooth muscle appearance is good after excision and not related to tumor type, location, histologic, or IH characteristics.
Clinical Relevance— Clinical importance could not be demonstrated for reclassification, but may be for future treatment, of intestinal smooth muscle or stromal tumors.     

Clinical Evaluation of a Novel Liquid Formulation of L-Thyroxine for Once Daily Treatment of Dogs with Hypothyroidism

Background: A liquid solution of levothyroxine (L-T4) is available for treatment of canine hypothyroidism.
Hypothesis: Once daily oral administration of a liquid L-T4 solution is effective and safe for controlling hypothyroidism in dogs.
Animals: Thirty-five dogs with naturally occurring hypothyroidism.
Methods: Dogs received L-T4 solution PO once daily at a starting dosage of 20 μg/kg body weight (BW). The dose was adjusted every 4 weeks, based on clinical signs and peak serum total T4 (tT4) concentrations. Target peak serum tT4 and thyroid stimulating hormone (TSH) concentrations, 4–6 hours posttreatment, were 35–95 nmol/L and < 0.68 ng/mL, respectively. Dogs were followed for up to 22 weeks after establishment of the maintenance dose.
Results: Clinical signs of hypothyroidism improved or resolved in 91% of dogs after 4 weeks of L-T4 treatment at 20 μg/kg once daily. The maintenance dose was established in 76, 94, and 100% of dogs after 4, 8, and 12 weeks of treatment, respectively. This was 20 μg L-T4/kg BW for 79% of the dogs, 30 μg/kg BW for 15%, and 10–15 μg/kg BW in the remaining 6%, once daily. Thereafter, median peak tT4 and TSH concentrations were 51 nmol/L and 0.18 ng/mL, respectively, and remained stable during the 22-week follow-up; clinical signs did not recur.
Conclusions and Clinical Importance: All of the hypothyroid dogs had rapid clinical and hormonal responses to supplementation with the PO-administered L-T4 solution. The starting dosage of 20 μg L-T4/kg BW once daily was suitable for 79% of dogs.     

MYELOGRAPHY VS. COMPUTED TOMOGRAPHY IN THE EVALUATION OF ACUTE THORACOLUMBAR INTERVERTEBRAL DISK EXTRUSION IN CHONDRODYSTROPHIC DOGS

Myelography and/or computed tomography (CT) are commonly used to evaluate acute intervertebral disk extrusion in chondrodystrophic dogs. The purpose of this study was to evaluate the sensitivity of myelography and two different CT protocols in determining level and lateralization of acute thoracolumbar intervertebral disk extrusion in comparison with surgical findings, investigate interobserver variability, and determine examination duration times. Results of conventional CT, helical CT, and myelography were compared with surgical findings in 19 chondrodystrophic dogs with acute thoracolumbar intervertebral disk extrusion. Agreement among investigators was determined for different imaging modalities, and examination times were recorded. In the diagnosis of level of disk extrusion there was agreement of myelography, conventional CT, and helical CT with surgical findings in 94.7%, 100%, and 94.7% of dogs, respectively ( P =0.144). In the diagnosis of level and lateralization of disk extrusion there was agreement of myelography, conventional CT, and helical CT with surgical findings in 78.9%, 87.4%, and 85.3% of dogs, respectively ( P =0.328). Interobserver agreement was very good for all imaging modalities (myelography κ=0.87; conventional CT κ=0.86; helical CT κ=0.95). There were significant differences in median examination duration times between helical CT (4 min), conventional CT (8 min), and myelography (32 min) ( P <0.001). Both helical and conventional CT appear to be accurate for evaluation of acute thoracolumbar intervertebral disk extrusion in chondrodystrophic dogs and are faster to perform than myelography.