Carl R. Jessen

Clinical, ultrasonographic, and laboratory findings associated with gallbladder disease and rupture in dogs: 45 cases (1997-2007).

OBJECTIVE To identify clinical, laboratory, and ultrasonographic characteristics associated with gallbladder disease and rupture in dogs. DESIGN Retrospective case series. ANIMALS 45 client-owned dogs. PROCEDURES Medical records of dogs with histologically confirmed gallbladder disease that had ultrasonographic evaluation were reviewed. Signalment, history, clinical signs, laboratory values, bacteriologic culture of bile, gallbladder status at surgery or necropsy (intact vs ruptured), histopathologic findings, radiographic findings, ultrasonographic findings, and outcome were analyzed. RESULTS The most common ultrasonographic findings were echogenic peritoneal fluid, thickened or laminated gallbladder wall, and echogenic reaction in the gallbladder fossa. Eighteen of 45 (40%) dogs had gallbladder rupture. Rupture was associated with histologic evidence of gallbladder necrosis, decreased serosal detail radiographically, and pericholecystic echogenic reaction, pericholecystic echogenic fluid, and generalized echogenic abdominal effusion ultrasonographically. Twenty-one of 45 (47%) dogs had mucocele, and 9 (43%) of those had gallbladder rupture. Eleven of 40 dogs had positive results of bacteriologic culture, and 5 of those had gallbladder rupture. Only 2 dogs had concurrent positive results of bacterial bile culture and gallbladder mucocele. Survival rate was 86% and not significantly related to presurgical bile leakage, positive results of bacterial culture, or mucocele. CONCLUSIONS AND CLINICAL RELEVANCE Ultrasonographic findings of pericholecystic reaction, localized or generalized echogenic peritoneal fluid, or decreased radiographic peritoneal detail should raise the index of suspicion for gallbladder rupture. Mucocele or bacterial gallbladder infection was the most common concurrent finding in dogs with gallbladder rupture.

Utility of diagnostic tests for and medical treatment of pulmonary blastomycosis in dogs: 125 cases (1989-2006)

OBJECTIVE To compare results of the most common diagnostic tests for pulmonary blastomycosis in dogs, identify factors associated with outcome, and determine response to various antifungal treatment protocols. DESIGN Retrospective case series. ANIMALS 125 dogs with pulmonary blastomycosis. PROCEDURES Medical records were reviewed, and information was obtained regarding diagnostic methods, results of routine laboratory testing, and radiographic response to antifungal treatment. RESULTS 79 dogs survived, 38 died, and 8 were euthanized. Transthoracic fine-needle aspiration and transtracheal lavage were the most common diagnostic methods. Results of an agar gel immunodiffusion test for antibodies against Blastomyces dermatitidis were negative in 12 of 24 (50%) dogs. Only 3 of 94 (3.2%) dogs in which cytologic or histologic examination or bacterial culture of pulmonary samples were performed had any evidence of concurrent bacterial infection. The half-time for radiographic resolution of pulmonary infiltrates did not vary significantly with antifungal treatment, and use of a loading dosage of itraconazole was not associated with significant improvements in outcome or time to disease resolution. Dogs that died had a higher number of band neutrophils at initial examination, compared with those that survived. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the agar gel immunodiffusion test should not be used as the sole diagnostic test for pulmonary blastomycosis in dogs, that concurrent bacterial pneumonia was uncommon in dogs with pulmonary blastomycosis, and that the rate with which pulmonary infiltrates resolved did not vary significantly among antifungal treatments.

Effect of Pancreatic Tissue Sampling on Serum Pancreatic Enzyme Levels in Clinically Healthy Dogs

Little is known about the potential consequences of pancreatic tissue sampling in dogs. The goal of the present study was to evaluate changes in serum trypsin–like immunoreactivity and canine-specific pancreatic lipase after pancreatic fine-needle aspiration and surgical biopsy in 27 clinically healthy dogs. Presurgical, ultrasound-guided aspiration of the pancreas was performed with the dogs under sedation. Subsequently, all the dogs underwent intraoperative pancreatic fine-needle aspiration and clamshell biopsy. After euthanasia, pancreata were sectioned for histopathologic evaluation. Serum pancreatic enzyme levels were measured at 3 time points: baseline, after ultrasound-guided aspiration, and after intraoperative aspiration and biopsy. No significant differences were detected among mean serum pancreatic lipase values at any point (P > 0.05). Serum trypsin–like immunoreactivity did not change from baseline (18.2 ± 2.1 μg/dl; mean ± standard error) after ultrasound-guided aspiration (13.6 ± 2.2 μg/dl) but increased significantly after intraoperative sampling (44.8 ± 1.9 μg/dl; P < 0.0005). After surgical biopsy, the 20 dogs that had both ultrasound-guided and intraoperative sampling had a higher mean (SE) serum trypsin–like immunoreactivity (44.8 ± 1.9 μg/dl) than the 7 dogs that had only intraoperative samples taken (36.4 ± 4.1 μg/dl; P < 0.05). All 27 pancreata were grossly normal before intraoperative sampling. Pancreatic sampling was associated with increased serum trypsin–like immunoreactivity and mild, peracute necrosis, inflammation, hemorrhage, and fibrin deposition. Tissue damage from sampling was not sufficient to cause an elevation in canine-specific pancreatic lipase in the time frame evaluated. Further studies are needed to determine longer-term effects of pancreatic sampling on enzyme levels and clinical outcome.

Radiographic findings in dogs with pulmonary blastomycosis: 125 cases (1989-2006).

OBJECTIVE To identify radiographic patterns in dogs with pulmonary blastomycosis and radiographic factors associated with outcome. DESIGN Retrospective case series. ANIMALS 125 dogs with pulmonary blastomycosis. PROCEDURES Medical records were reviewed, and for each lung lobe, the primary radiographic pattern and percentage of lobar involvement at the time of initial examination were recorded. RESULTS 79 dogs survived, 38 died, and 8 were euthanized without treatment. The initial radiographic pattern was variable and not significantly associated with outcome. Mean half-time for radiographic resolution of pulmonary infiltrates was 41.4 days for all patterns except masses, for which mean half-time to resolution was 90.8 days. Transient radiographic worsening was seen in 20 of 87 (23%) dogs but was not associated with a poor prognosis. Pulmonary bullae were seen in 20 (16%) dogs, most often in association with an alveolar pattern. Accuracy of using percentage of right caudal lung lobe involvement (<or= 20% vs > 20%) to predict outcome was 74.4%; accuracy of using number of affected lobes (< 4 vs >or= 4) to predict outcome was 65.8%. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that a nonuniform distribution of pulmonary infiltrates was equally as likely as a diffuse nodular interstitial pattern in dogs with pulmonary blastomycosis. On the basis of half-time for resolution of pulmonary infiltrates, follow-up radiography should be performed no more often than every 4 to 6 weeks in clinically stable patients. Transient radiographic worsening that occurred during the initial weeks of treatment was not associated with a poorer prognosis.

Clinical features, intestinal histopathology, and outcome in protein-losing enteropathy in Yorkshire Terrier dogs.

Background A poorly understood protein‐losing enteropathy (PLE) disorder has been reported in Yorkshire Terrier dogs. Objectives To describe clinical features, intestinal histopathology, and outcome in Yorkshire Terrier dogs with PLE, and to identify variables predictive of outcome. Animals Thirty client‐owned Yorkshire Terrier dogs with PLE. Methods Retrospective study. Records of dogs with a diagnosis of PLE were reviewed. Intestinal histopathology was interpreted using the World Small Animal Veterinary Association gastrointestinal histopathology classification system. Discriminate analysis techniques were used to identify variables predictive of outcome. Results Females outnumbered males (20/30). Median age was 7 years (range 1–12). Common clinical signs were diarrhea (20/30), vomiting (11), ascites and abdominal distension (11), and respiratory difficulty (8). Histopathologic abnormalities included villous lymphatic dilatation, crypt lesions, villous stunting, and variable increases in cellularity of the lamina propria. All dogs were treated with glucocorticoids. Of 23 dogs with long‐term follow‐up, 9 had complete, and 3 had partial, resolution of signs, and 11 failed to respond to treatment. Median survival of responders was 44 months and of nonresponders was 12 months, with 4 dogs experiencing peracute death. Vomiting, monocytosis, severity of hypoalbuminemia, low blood urea nitrogen concentration, and villous blunting were predictive of survival <4 months. Conclusions In addition to classic GI signs, Yorkshire Terriers with PLE often show clinical signs associated with hypoalbuminemia and low oncotic pressure. Lymphatic dilatation, crypt lesions, and villous stunting are consistent histopathologic findings. Clinical outcomes are variable, but many dogs experience remission of clinical signs and prolonged survival.

Relative metabolite concentrations and ratios determined by use of 3-T region-specific proton magnetic resonance spectroscopy of the brain of healthy Beagles

OBJECTIVE To determine relative concentrations of selected major brain tissue metabolites and their ratios and lobar variations by use of 3-T proton (hydrogen 1 [(1)H]) magnetic resonance spectroscopy (MRS) of the brain of healthy dogs. ANIMALS 10 healthy Beagles. PROCEDURES 3-T (1)H MRS at echo times of 144 and 35 milliseconds was performed on 5 transverse slices and 1 sagittal slice of representative brain lobe regions. Intravoxel parenchyma was classified as white matter, gray matter, or mixed (gray and white) and analyzed for relative concentrations (in arbitrary units) of N-acetylaspartate (NAA), choline, and creatine (ie, height at position of peak on MRS graph) as well as their ratios (NAA-to-choline, NAA-to-creatine, and choline-to-creatine ratios). Peak heights for metabolites were compared between echo times. Peak heights for metabolites and their ratios were correlated and evaluated among matter types. Yield was calculated as interpretable voxels divided by available lobar voxels. RESULTS Reference ranges of the metabolite concentration ratios were determined at an echo time of 35 milliseconds (NAA-to-choline ratio, 1.055 to 2.224; NAA-to-creatine ratio, 1.103 to 2.161; choline-to-creatine ratio, 0.759 to 1.332) and 144 milliseconds (NAA-to-choline ratio, 0.687 to 1.788; NAA-to-creatine ratio, 0.984 to 2.044; choline-to-creatine ratio, 0.828 to 1.853). Metabolite concentration ratios were greater in white matter than in gray matter. Voxel yields ranged from 43% for the temporal lobe to 100% for the thalamus. CONCLUSIONS AND CLINICAL RELEVANCE Metabolite concentrations and concentration ratios determined with 3-T (1)H MRS were not identical to those in humans and were determined for clinical and research investigations of canine brain disease.

Imaging Canine Urocystoliths: Detection and Prediction of Mineral Content

The role of survey radiography, contrast radiography, and ultrasonography in the assessment of urocystolithiasis has been primarily one of detection. Information about the radiographic characteristics of uroliths (size, shape, radiopacity, surface characteristics, number detected) for characterization and diagnosis of urocystolithiasis is emerging; however, there are no studies on the accuracy or sensitivity of these techniques. In this article, the intent is to update knowledge about available imaging techniques used in the detection and characterization of urocystoliths based on recent studies designed to evaluate their accuracy in prediction of different urocystoliths mineral content.

OPTIMIZING A PROTOCOL FOR 1H‐MAGNETIC RESONANCE SPECTROSCOPY OF THE CANINE BRAIN AT 3T

Intracranial diseases are common in dogs and improved noninvasive diagnostic tests are needed. Magnetic resonance (MR) spectroscopy is a technique used in conjunction with conventional MR imaging to characterize focal and diffuse pathology, especially in the brain. As with conventional MR imaging, there are numerous technical factors that must be considered to optimize image quality. This study was performed to develop an MR spectroscopy protocol for routine use in dogs undergoing MR imaging of the brain. Fifteen canine cadavers were used for protocol development. Technical factors evaluated included use of single-voxel or multivoxel acquisitions, manual placement of saturation bands, echo time (TE), phase- and frequency-encoding matrix size, radiofrequency coil, and placement of the volume of interest relative to the calvaria. Spectrum quality was found to be best when utilizing a multivoxel acquisition with the volume of interest placed entirely within the brain parenchyma without use of manually placed saturation bands, TE = 144 ms, and a quadrature extremity radiofrequency coil. An 18 × 18 phase- and frequency-encoding matrix size also proved optimal for image quality, specificity of voxel placement, and imaging time.

Multivoxel proton magnetic resonance spectroscopy of inflammatory and neoplastic lesions of the canine brain at 3.0 T

OBJECTIVE To describe findings of 3.0-T multivoxel proton magnetic resonance spectroscopy ((1)H-MRS) in dogs with inflammatory and neoplastic intracranial disease and to determine the applicability of (1)H-MRS for differentiating between inflammatory and neoplastic lesions and between meningiomas and gliomas. ANIMALS 33 dogs with intracranial disease (19 neoplastic [10 meningioma, 7 glioma, and 2 other] and 14 inflammatory). PROCEDURES 3.0-T multivoxel (1)H-MRS was performed on neoplastic or inflammatory intracranial lesions identified with conventional MRI. N-acetylaspartate (NAA), choline, and creatine concentrations were obtained retrospectively, and metabolite ratios were calculated. Values were compared for metabolites separately, between lesion categories (neoplastic or inflammatory), and between neoplastic lesion types (meningioma or glioma) by means of discriminant analysis and 1-way ANOVA. RESULTS The NAA-to-choline ratio was 82.7% (62/75) accurate for differentiating neoplastic from inflammatory intracranial lesions. Adding the NAA-to-creatine ratio or choline-to-creatine ratio did not affect the accuracy of differentiation. Neoplastic lesions had lower NAA concentrations and higher choline concentrations than inflammatory lesions, resulting in a lower NAA-to-choline ratio, lower NAA-to-creatine ratio, and higher choline-to-creatine ratio for neoplasia relative to inflammation. No significant metabolite differences between meningiomas and gliomas were detected. CONCLUSIONS AND CLINICAL RELEVANCE (1)H-MRS was effective for differentiating inflammatory lesions from neoplastic lesions. Metabolite alterations for (1)H-MRS in neoplasia and inflammation in dogs were similar to changes described for humans. Use of (1)H-MRS provided no additional information for differentiating between meningiomas and gliomas. Proton MRS may be a beneficial adjunct to conventional MRI in patients with high clinical suspicion of inflammatory or neoplastic intracranial lesions.

Outcome of 45 Dogs With Laryngeal Paralysis Treated by Unilateral Arytenoid Lateralization or Bilateral Ventriculocordectomy

The purpose of this retrospective study was to assess risk factors and complications affecting postoperative outcome of dogs with laryngeal paralysis treated by either unilateral arytenoid lateralization (UAL) or bilateral ventriculocordectomy (VCC). Medical records of all dogs having either UAL or VCC between 2000 and 2011 were analyzed. Twenty-five dogs had VCC and 20 dogs had UAL. The overall postoperative complications rates for VCC and UAL were similar (52% and 60%, respectively; P = .0887). Dogs that had UAL were more likely to have acute postoperative respiratory distress and aspiration pneumonia (P = .0526). Dogs with VCC were more likely to have chronic postoperative respiratory distress and aspiration pneumonia (P = .0079). Revision surgery was required in 6 dogs (24%) following VCC and 2 dogs (10%) following UAL. Sex, breed, presenting complaint, type of service provided, and concurrent diseases were not significantly associated with higher risk of either death or decreased survival time postoperatively with either procedure. Overall postoperative complication rates, required revision surgeries, and episodes of aspiration pneumonia were similar in dogs undergoing UAL and VCC surgeries. Dogs that had VCC appeared to have an increased risk of lifelong complications postoperatively compared with UAL; therefore, VCC may not be the optimal choice for treatment of laryngeal paralysis.