Rapid brain MRI protocols result in comparable differential diagnoses versus a full brain protocol in most canine and feline cases.

Evaluation of brain disease in veterinary patients uses a wide variety of MRI sequences. A shortened protocol that maintains consistency of interpretation would reduce radiologist reporting time, patient anesthetic time, and client cost. The aims of this retrospective, methods comparison, observer agreement study were to evaluate whether abbreviated MRI protocols alter differential diagnoses and recommendations compared to our institution's standard protocol; evaluate interobserver agreement on standard brain MRIs; and assess whether differential diagnoses change after postcontrast images. Normal and pathologic canine and feline brain MRIs were retrieved from hospital archives. Three protocols were created from each: a 5-sequence noncontrast enhanced Fast Brain Protocol 1 (FBP1); a 6-sequence contrast-enhanced Fast Brain Protocol 2 (FBP2); and an 11-sequence standard brain protocol (SBP). Three blinded veterinary radiologists interpreted FBP images for 98 cases (1 reader/case) and SBP images for 20 cases (3 readers/case). A fourth observer compared these interpretations to the original MRI reports (OMR). Overall agreement between FBPs and OMR was good (k = 0.75) and comparable to interobserver agreement for multiple reviews of SBP cases. Postcontrast images substantially altered conclusions in 17/97 cases (17.5%), as well as improved interobserver agreement compared to noncontrast studies. The conclusions reached with shortened brain protocols were comparable to those of a full brain study. The findings supported the use of a 6-sequence brain MRI protocol (sagittal T2-weighted [T2w] TSE; transverse T2w turbo spin echo fluid-attenuated inversion recovery, T2*-weighted gradient recalled echo, T1-weighted spin echo, and diffusion weighted imaging/apparent diffusion coefficient; and postcontrast transverse T1-weighted spin echo) for dogs and cats with suspected intracranial disease.

Treatment of naturally occurring asthma with inhaled fluticasone or oral prednisolone: A randomized pilot trial.

The objective of this study was to compare inhaled glucocorticoids with oral glucocorticoids for treatment of naturally occurring feline asthma. Secondary goals were to evaluate serum allergy testing results in cats and to quantify the effect of an inhaled glucocorticoid (fluticasone) on glucose homeostasis. Nine cats with asthma were enrolled on the basis of clinical signs, thoracic radiographic findings, and airway eosinophilia. Cats were randomized and 4 cats were treated with oral glucocorticoids and 5 cats with inhaled glucocorticoids, with a 7-day course of oral glucocorticoids overlapping at the start of therapy. Cats were evaluated at baseline and at 8 wk with thoracic radiographs, bronchoalveolar lavage, lung function testing, and fructosamine levels. Serum allergen panels were evaluated. All cats were clinically normal after treatment and had significantly improved airway eosinophilia and decreased nucleated cell count. No improvement was seen in radiographic changes after treatment with either therapy. Oral, but not inhaled glucocorticoids, caused a decrease in airway resistance, although cats in the inhaled group had a higher baseline resistance than those in the oral group. Fructosamine levels did not change with treatment. Fifty percent of cats tested positive for immunoglobulin E (IgE) antibodies. Asthma is a heterogeneous condition; individual cats responded well to both oral and inhaled glucocorticoids. Ongoing evaluation of the potential underlying causes and therapeutic options is warranted with a larger group of cats.

L'objectif de l'étude était de comparer le traitement de l'asthme félin avec des glucocorticoïdes inhalés et administrés par voie entérale. Les objectifs secondaires étaient d'évaluer les résultats de tests d'allergies de chats atteints d'asthme félin et de quantifier l'effet d'un glucocorticoïde inhalé (fluticasone) sur l'homéostasie du glucose. Neuf chats atteints d'asthme félin ont été recrutés selon les signes cliniques, les trouvailles radiographiques et les évaluations cytologiques des voies aériennes (éosinophilie). Les chats ont été randomisés. Quatre chats ont été traités avec des glucocorticoïdes par voie entérale et cinq chats avec des glucocorticoïdes inhalés dont les 7 premiers jours ont été associés à l'administration de glucocorticoïdes par voie orale. Les chats ont initialement été évalués au moment du recrutement et puis à huit semaines avec des radiographies thoraciques, lavage bronchoalvéolaire, tests de fonction pulmonaire et dosage de la fructosamine. Des tests sériques d'allergènes ont également été évalués. Tous les chats ont eu une résolution des signes cliniques après le traitement et avaient une amélioration significative du compte éosinophilique du LBA. Aucune amélioration des lésions radiographiques suivant le traitement soit inhalé ou entéral n'a été observée. Seuls les glucocorticoïdes entéraux ont causés une diminution de la résistance des voies respiratoires. Toutefois les chats du groupe de traitement de glucocorticoïdes inhalés avaient, avant l'initiation du traitement, une résistance pulmonaire plus importante. Les niveaux de fructosamine n'ont pas changé significativement, et ce dans les deux groupes de traitement. 50 % des chats ont testé positif pour des anticorps IgE contre des allergènes inhalés communs. L'asthme est une entité clinique hétérogène; les chats ont individuellement bien répondu autant au traitement inhalé qu'au traitement entéral. L'étude des potentielles causes sous-jacente et des différentes options thérapeutiques sont recommandées dans une population plus grande de chats.(Traduit par les auteurs).

Atypical and malignant canine intracranial meningiomas may have lower apparent diffusion coefficient values than benign tumors.

Canine intracranial meningiomas can be graded based on histological classification as benign (grade I), atypical (grade II), and anaplastic or malignant (grade III). In people, grade II/III meningiomas behave more aggressively, have a higher potential for recurrence after surgical resection, and have lower apparent diffusion coefficient (ADC) values with diffusion weighted imaging (DWI). In this retrospective analytical cross-sectional study, 42 dogs had ADC values quantified in an attempt to differentiate tumor histologic grade. Our hypothesis was that ADC values would be significantly lower in grade II and III versus grade I meningiomas in dogs. On each ADC image, a polygonal region of interest (ROI) was hand-drawn along the lesion's periphery, excluding fluid-filled and hemorrhagic regions. Mean ADC value (ADCmean ) and minimum ADC value (ADCmin ) were calculated. Additionally, two smaller, ovoid ROI were drawn within the lesion with mean ADC calculated (ADCmean sR and ADCmin sR ). Normalized ADC values using white matter were also calculated (ADCn and ADCn sR ). Grades of each tumor were assigned based on histopathology review. Association between ADC parameters and histological grade was tested by means of two-sample t-tests. There were 14 grade I (33.3%), 25 grade II (59.5%), and three grade III (7.2%) meningiomas. ADCmean sR and ADCmin sR were significantly lower when comparing grade II/III to grade I (P < .05). Grade II tumors had significantly lower ADCmean , ADCmean sR , ADCmin sR , ADCn , and ADCn sR than grade I meningiomas. This preliminary study supports the potential of ADC values to help predict the histological grade of intracranial meningiomas in dogs.

Evaluation of gastrointestinal activity in healthy rabbits by means of duplex Doppler ultrasonography.

OBJECTIVE: To use duplex Doppler ultrasonography to compare gastrointestinal activity in healthy sedated versus nonsedated rabbits and to evaluate agreement between B-mode and pulsed-wave Doppler (PWD) ultrasonographic measurements. ANIMALS: 10 healthy client-owned rabbits brought for routine physical examination and 11 brought for routine ovariohysterectomy or castration. PROCEDURES: Duplex Doppler ultrasonography of the gastrointestinal tract was performed once for the 10 rabbits that underwent physical examination and twice (before and after presurgical sedation) for the 11 rabbits that underwent routine ovariohysterectomy or castration. Mean number of peristaltic contractions during a 30-second period was determined for the stomach, duodenum, jejunum, cecum, and colon from B-mode and PWD ultrasonographic images that had been video recorded. Findings for the duodenum and jejunum were compared between B-mode and PWD ultrasonography and between sedated and nonsedated rabbits. RESULTS: Duodenal and jejunal segments had measurable peristaltic waves; however, the stomach, cecum, and colon had no consistent measurable activity. B-mode and PWD ultrasonographic measurements for the duodenum and jejunum had high agreement. No significant difference was identified between nonsedated and sedated rabbits in mean number of peristaltic contractions of the duodenum or jejunum. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that both B-mode and PWD ultrasonography of the duodenum and jejunum may be suitable for noninvasive evaluation of small intestinal motility in rabbits and that the sedation protocol used in this study had no impact on measured peristaltic values.

Radiographic Differentiation of Cranial Mediastinal Lymphomas from Thymic Epithelial Tumors in Dogs and Cats.

In both dogs and cats, the most common cranial mediastinal masses (CMMs) are lymphoma and thymic epithelial tumors (TETs). Pretreatment differentiation of these tumors using fine needle aspiration or biopsy is essential because lymphomas are treated medically, whereas TETs are treated surgically. The purpose of this retrospective study was to determine whether thoracic radiographic findings can be used to aid clinicians in preliminarily differentiating the two tumor types before cytology or histopathology results become available. Medical records, available cytologic or histologic samples, and thoracic radiographs were evaluated for 62 dogs and 28 cats. Seventeen radiographic criteria were assessed by two examiners, and regression modeling was performed to test for significant predictors of tumor type. In dogs, CMMs with at least two well-defined radiographic margins on a lateral view and CMMs causing a rightward shift of the cardiac silhouette on a ventrodorsal or dorsoventral view were significantly more likely to be TETs than lymphomas (P < .001 and P < .01, respectively). No significant predictive variables were identified in cats. Radiographic findings do not eliminate the need for invasive sampling, but in dogs, they may guide the clinician in providing preliminary information to owners regarding the staging and therapeutic measures that may eventually be recommended.

Early and Increased Training in Veterinary Radiology Increases Student Interest in the Specialty But May Provide Little Short-Term Gain in Radiology Knowledge.

There is a lack of consensus among educators regarding the ideal structure of radiology training in veterinary medicine. Research in the medical field suggests that early integration has positive short- and long-term impacts on student interest in radiology. This study evaluated the effect of a new radiology course in the first year of the veterinary curriculum. Authors hypothesized that students taught radiology in years 1 and 2 would have greater interest in and appreciation for the specialty of radiology and would perform better on tests of basic knowledge of medical imaging principles, entry-level image interpretation, and anatomy identification than students who were not taught until year 2. An online questionnaire was administered to different classes of students after completion of their radiology courses. Students with early and increased radiology training were significantly more likely to respond that radiology was more interesting than other veterinary specialties. Unexpectedly, students with early and increased training performed significantly better than students with less and later training on only one out of nine content knowledge questions, though they did perform significantly better on additional knowledge questions compared to students with only early exposure. This suggests early and increased training in radiology may increase student interest in and appreciation for the specialty, but may not lead to increased short-term knowledge retention compared to a traditional curriculum format.

Lung lobe torsion in 35 dogs and 4 cats.

The purpose of this study was to assess survival to discharge of animals with surgical or postmortem confirmation of a lung lobe torsion (LLT) as well as to evaluate pre-operative effusion, lung lobe affected, and patient size as prognostic indicators. Medical records search identified 35 dogs and 4 cats with a confirmed diagnosis including 17 small-breed dogs, 18 large-breed dogs, 3 domestic shorthair cats, and 1 minskin cat. Lobes affected included right middle (n = 18), left cranial (n = 18), right cranial (n = 2), left caudal (n = 1), and accessory (n = 1). Two animals died before surgery; the remaining 37 animals underwent thoracotomy. All treated small-breed dogs and cats survived; 12/18 large-breed dogs survived, with an overall survival to discharge of 87%. Pre-operative pleural effusion and affected lung lobe did not affect survival to discharge in this population. Small dogs and cats with LLT appear to have an excellent survival to discharge following thoracotomy and the survival is good in larger dogs.

Torsion de lobe pulmonaire chez 35 chiens et 4 chats. Le but de cette étude est d'évaluer le taux de survie jusqu'à la sortie d'hôpital, chez des animaux ayant eu confirmation chirurgicale ou post-mortem de torsion de lobe pulmonaire (TLP), ainsi que d'évaluer la présence d'épanchement pleural, le lobe pulmonaire affecté et la taille des patients en tant que facteurs pronostics. Les dossiers médicaux de 35 chiens et 4 chats avec un diagnostic de TLP confirmé furent identifiés, comprenant 17 chiens de petite race, 18 chiens de grande race, 3 chats Européens et 1 Minskin. Les lobes pulmonaires affectés étaient le lobe moyen droit (n = 18), le lobe cranial gauche (n = 18), le lobe cranial droit (n = 2), le lobe caudal gauche (n = 1) et le lobe accessoire (n = 1). Deux animaux décédèrent avant chirurgie, et une thoracotomie fut pratiquées chez les 37 animaux restant. Tous les chiens de petites races et les chats survécurent à leur chirurgie; 12/18 des chiens de grande race survécurent, et le taux de survie global était de 87 %. La présence d'épanchement pleural et le lobe pulmonaire affecté n'avaient pas d'influence sur la probabilité de survie dans cette population. Le taux de survie au congé hospitalier semble excellent chez les chiens de petite taille et les chats diagnostiqués avec une torsion de lobe pulmonaire et il est bon pour les chiens de grande taille.(Traduit par les auteurs).

Metallosis in a Dog as a Long-Term Complication Following Total Hip Arthroplasty.

Metallosis is the accumulation of metallic debris in soft tissues resulting from wear following total joint replacement. A dog was evaluated for lameness 4 years after total hip arthroplasty using a titanium alloy and cobalt chromium total hip system. Radiographs revealed severe acetabular component wear, implant-bone interface deterioration, and peri-acetabular osteolysis. During surgical revision, black periarticular tissue surrounded the implants. Histologically, there was fibrosis and granulomatous inflammation with abundant, intra- and extracellular, black, granular material and smaller amounts of clear punctate to acicular material. Laser capture microdissection followed by x-ray fluorescence microscopy indicated the material contained large amounts of titanium with smaller amounts of vanadium, cobalt, and chromium, confirming the diagnosis of metallosis. The clear material was birefringent under cross-polarized light, stained positive with Oil-Red-O, and thus was consistent with polyethylene. Metallosis exhibits characteristic gross and histologic lesions and is a differential diagnosis for aseptic loosening of hip implants.

A valentine-shaped cardiac silhouette in feline thoracic radiographs is primarily due to left atrial enlargement.

Conflicting information has been published regarding the cause of a valentine-shaped cardiac silhouette in dorsoventral or ventrodorsal thoracic radiographs in cats. The purpose of this retrospective, cross-sectional study was to test the hypothesis that the valentine shape is primarily due to left atrial enlargement. Images for cats with a radiographic valentine-shaped cardiac silhouette and full echocardiography examination were retrieved and independently reviewed. A subjective scoring system was used to record severity of radiographic valentine shape. Subjective radiographic evidence of left atrial enlargement in a radiographic lateral projection and a final diagnosis based on medical records were also recorded. A total of 81 cats met inclusion criteria. There was a strong positive correlation (P < 0.001) between echocardiographic left atrial size and severity of radiographic valentine shape. There was no effect of echocardiographic right atrial size on the severity of valentine shape, except when concurrent with severe left atrial enlargement. In this situation, right atrial enlargement increased the likelihood of observing a severe valentine shape. There was no effect of right atrial enlargement on the shape of the cardiac silhouette when left atrial enlargement was absent or only mild to moderate. There was no correlation between the category of final diagnosis of cardiac disease and the severity of valentine shape. Findings from this study supported the hypothesis that a valentine-shaped cardiac silhouette in radiographs is due primarily to left atrial enlargement in cats, with right atrial enlargement only impacting the shape if concurrent with severe left atrial enlargement.

Sensitivity, positive predictive value, and interobserver variability of computed tomography in the diagnosis of bullae associated with spontaneous pneumothorax in dogs: 19 cases (2003-2012).

OBJECTIVE: To determine the sensitivity, positive predictive value, and interobserver variability of CT in the detection of bullae associated with spontaneous pneumothorax in dogs. DESIGN: Retrospective case series. ANIMALS: 19 dogs with spontaneous pneumothorax caused by rupture of bullae. PROCEDURES: Dogs that had CT for spontaneous pneumothorax caused by rupture of bullae confirmed at surgery (median sternotomy) or necropsy were included. Patient signalment, CT protocols, and bulla location, size, and number were obtained from the medical records. Computed tomographic images were reviewed by 3 board-certified radiologists who reported on the location, size, and number of bullae as well as the subjective severity of pneumothorax. RESULTS: Sensitivities of the 3 readers for bulla detection were 42.3%, 57.7%, and 57.7%, with positive predictive values of 52.4%, 14.2%, and 8.4%, respectively, with the latter 2 readers having a high rate of false-positive diagnoses. There was good interobserver agreement (κ = 0.640) for correct identification of bullae. Increasing size of the bulla was significantly associated with a correct CT diagnosis in 1 reader but not in the other 2 readers. Correct diagnosis was not associated with slice thickness, ventilation protocol, or degree of pneumothorax. CONCLUSIONS AND CLINICAL RELEVANCE: Sensitivity and positive predictive value of CT for bulla detection were low. Results suggested that CT is potentially an ineffective preoperative diagnostic technique in dogs with spontaneous pneumothorax caused by bulla rupture because lesions can be missed or incorrectly diagnosed. Bulla size may affect visibility on CT.

T-cell function is critical for murine cholesterol gallstone formation.

BACKGROUND & AIMS: The formation of cholesterol gallstones is a complex process involving contributions from genes and environmental factors. Although gallbladder inflammation is believed to be common during cholelithogenesis, the role of immunologic factors is unknown. METHODS: The role of adaptive immunity in cholesterol cholelithogenesis was analyzed utilizing immunocompetent Helicobacter spp.-infected and -uninfected BALB/c and congenic immunodeficient Rag2(-/-) (Rag) mice. Lymphocyte transfer studies were performed to determine which cellular subset was responsible for cholesterol gallstone formation. Also, gallbladder inflammation was quantified to determine the nature of the inflammatory response associated with cholelilithogenesis. RESULTS: When fed a lithogenic diet for 8 weeks, wild-type mice developed significantly more cholesterol gallstones (27%-80% prevalence) than Rag mice ( approximately 5%, P < .05). Helicobacter spp.-infected BALB/cJ mice displayed statistically significant increases in cholesterol gallstone prevalence compared with uninfected mice (81% vs. 39%; P < .05). Transfer of splenocytes or T lymphocytes to Rag2(-/-) mice increased stone prevalence markedly (26% and 40% respectively; P < .05), whereas transfer of B cells was not appreciably cholelithogenic (13%). The adaptive immune response increased the expression of gallbladder Muc genes and accumulation of mucin gel. In addition, T cells and cholesterol monohydrate crystals induced proinflammatory gene expression in the gallbladder, which likely contributes to gallbladder dysfunction. CONCLUSIONS: These studies indicate that T cells are critical in murine cholesterol cholelithogenesis. Furthermore, cholesterol monohydrate crystals induce expression of proinflammatory cytokines in a T-cell-dependent fashion. Acquired immunity and inflammation are likely to be crucial factors in cholesterol gallstone pathogenesis, rather then merely the result of cholelithogenesis.

Association of expiratory airway dysfunction with marked obesity in healthy adult dogs.

OBJECTIVE: To evaluate the effects of obesity on pulmonary function in healthy adult dogs. ANIMALS: 36 Retrievers without cardiopulmonary disease. PROCEDURES: Dogs were assigned to 1 of 3 groups on the basis of body condition score (1 through 9): nonobese (score, 4.5 to 5.5), moderately obese (score, 6.0 to 6.5), and markedly obese (score, 7.0 to 9.0). Pulmonary function tests performed in conscious dogs included spirometry and measurement of inspiratory and expiratory airway resistance (R(aw)) and specific R(aw) (sR(aw)) during normal breathing and during hyperpnea via head-out whole-body plethysmography. Functional residual capacity (FRC; measured by use of helium dilution), diffusion capacity of lungs for carbon monoxide (DLCO), and arterial blood gas variables (PaO(2), PaCO(2), and alveolar-arterial gradient) were assessed. RESULTS: During normal breathing, body condition score did not influence airway function, DLCO, or arterial blood gas variables. During hyperpnea, expiratory sR(aw) was significantly greater in markedly obese dogs than nonobese dogs and R(aw) was significantly greater in markedly obese dogs, compared with nonobese and moderately obese dogs. Although not significantly different, markedly obese dogs had a somewhat lower FRC, compared with other dogs. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, obesity appeared to cause airflow limitation during the expiratory phase of breathing, but this was only evident during hyperpnea. This suggests that flow limitation is dynamic and likely occurs in the distal (rather than proximal) portions of the airways. Further studies are warranted to localize the flow-limited segment and understand whether obesity is linked to exercise intolerance via airway dysfunction in dogs.

Plethysmographic comparison of breathing pattern in heaves (recurrent airway obstruction) versus experimental bronchoconstriction or hyperpnea in horses.

BACKGROUND: Horses with recurrent airway obstruction (heaves) are described as exhibiting "increased abdominal effort," but it is unknown whether this translates to an effective contribution to ventilation. HYPOTHESIS: We hypothesized that heaves is characterized by asynchrony between rib cage and abdominal motions, and that the abdominal component is the major contributor to ventilation. ANIMALS: The rib cage versus abdominal motion in naturally occurring heaves (n = 15) was compared to controls at rest (n = 7) and during hyperpnea because of lobeline treatment, and the effects of histamine-induced bronchoconstriction in controls (n = 10). METHODS: Flow patterns, phase angle (theta) between the rib and abdominal compartments, abdominal (Vabd) contribution to tidal volume (VT), and lung mechanics were measured. RESULTS: Findings unique to the heaves group included the loss of biphasic expiratory flow, severely increased theta with the abdomen consistently lagging behind the rib cage, and a reduced contribution of the abdomen to ventilation. A subgroup of heaves (n = 5) with abdominal paradox showed a significant (P < .05) reduction in tidal volume, and increased respiratory rate. Bronchodilation reduced theta in heaves (P = .06), but theta remained significantly higher after bronchodilation than found in controls. CONCLUSIONS AND CLINICAL IMPORTANCE: We conclude that breathing pattern in horses with heaves is characterized by severe rib cage/abdominal asynchrony, with the rib cage motion in synchrony with flow, therefore dominating ventilation. In a subset of heaves, the abdominal compartment (diaphragm, abdominal muscles) was completely out of synchrony with flow ("abdominal paradox") despite the clinical appearance of "increased abdominal effort."

Feline aminopeptidase N is not a functional receptor for avian infectious bronchitis virus.

BACKGROUND: Coronaviruses are an important cause of infectious diseases in humans, including severe acute respiratory syndrome (SARS), and have the continued potential for emergence from animal species. A major factor in the host range of a coronavirus is its receptor utilization on host cells. In many cases, coronavirus-receptor interactions are well understood. However, a notable exception is the receptor utilization by group 3 coronaviruses, including avian infectious bronchitis virus (IBV). Feline aminopeptidase N (fAPN) serves as a functional receptor for most group 1 coronaviruses including feline infectious peritonitis virus (FIPV), canine coronavirus, transmissible gastroenteritis virus (TGEV), and human coronavirus 229E (HCoV-229E). A recent report has also suggested a role for fAPN during IBV entry (Miguel B, Pharr GT, Wang C: The role of feline aminopeptidase N as a receptor for infectious bronchitis virus. Brief review. Arch Virol 2002, 147:2047-2056. RESULTS: Here we show that, whereas both transient transfection and constitutive expression of fAPN on BHK-21 cells can rescue FIPV and TGEV infection in non-permissive BHK cells, fAPN expression does not rescue infection by the prototype IBV strain Mass41. To account for the previous suggestion that fAPN could serve as an IBV receptor, we show that feline cells can be infected with the prototype strain of IBV (Mass 41), but with low susceptibility compared to primary chick kidney cells. We also show that BHK-21 cells are slightly susceptible to certain IBV strains, including Ark99, Ark_DPI, CA99, and Iowa97 (<0.01% efficiency), but this level of infection is not increased by fAPN expression. CONCLUSION: We conclude that fAPN is not a functional receptor for IBV, the identity of which is currently under investigation.