OBJECTIVE To predict histologic grade of meningiomas in dogs via texture analysis (TA) of MRI scans of the brain and spinal cord. SAMPLE 58 sets of MRI scans of the brain and spinal cord of dogs with histologically diagnosed meningioma. PROCEDURES MRI sequences were divided into a training set and a test set, and results of histologic assessment were obtained. Tumors were histologically grouped as benign (stage I) or atypical-anaplastic (stage II or III). Texture analysis was performed by use of specialized software on T2-weighted (T2W) and pre- and postcontrast T1-weighted (T1W) images. A set of 30 texture features that provided the highest discriminating power between the 2 histologic classes in the training set was automatically selected by the TA software. Linear discriminant analysis was performed, and the most discriminant factor (MDF) was calculated. The previously selected texture features were then used for linear discriminant analysis of the test set data, and the MDF was calculated. RESULTS For the training set, TA of precontrast T1W images provided the best diagnostic accuracy; a cutoff MDF of < 0.0057 resulted in a sensitivity of 97.4% and specificity of 95.0% for discriminating benign from atypical-anaplastic meningiomas. Use of postcontrast T1W and T2W images yielded poorer diagnostic performances. Application of the MDF cutoff calculated with the training set to the MDF calculated with the test set provided a correct classification rate of 96.8% for precontrast T1W images, 92.0% for postcontrast T1W images, and 78.9% for T2W images. CONCLUSIONS AND CLINICAL RELEVANCE Findings supported the potential clinical usefulness of TA of MRI scans for the grading of meningiomas in dogs.

Myocardial dysfunction occurs in cats with hypertrophic cardiomyopathy (HCM), but little is known about the early stages of the disease. Strain imaging echocardiography is a method that enables the quantitative assessment of myocardial function and deformity, allowing the characterization of systolic dysfunction. The objective of this study was to assess systolic function using strain imaging echocardiography in Maine coon cats genetically tested for the A31P mutation in the MYBPC3 gene, with and without ventricular hypertrophy. For this purpose, 57 Maine coon cats of both genders, with an unknown status regarding the mutation at inclusion, were included prospectively and evaluated by conventional and strain imaging echocardiography. Comparisons were made among cats without hypertrophy (n = 45), suspect cats (n = 7), and cats with hypertrophic cardiomyopathy (n = 5), and also between the heterozygous for the mutation group (n = 26) and the negative for the mutation group (n = 28). Finally, in the group of phenotypically normal cats, heterozygous cats carrying the mutation were compared to cats without the mutation. Strain values were compared among the groups (blinded prospective study). While echocardiography demonstrated normal contractility, strain values (middle of the septum) were lower in HCM cats. Strain values (base of anterior wall of the left ventricle) were lower in heterozygous than in negative cats, even before hypertrophy. Negative correlation was observed between some values of myocardial strain and thickness. While strain imaging echocardiography was able to detect systolic abnormalities, despite apparent normality on conventional echocardiography, it was not able to identify cats that carry the A31P mutation in the MYBPC3 gene. Strain imaging echocardiography could be a useful tool, however, for detecting systolic alterations in HCM cats with an apparently normal systolic function or for detecting alterations in normal carriers of the MYBPC3 gene mutation.

OBJECTIVE To evaluate a hypervariable octameric oligonucleotide fingerprints (HOOF-Prints) assay for identification of and discrimination between wild-type and vaccine strains of Brucella melitensis. SAMPLE Brucella melitensis vaccine strain M5 and wild-type strain M43. PROCEDURES 8 pairs of primers (alterable, octameric nucleotides) were designed on the basis of a biological analysis of 8 flanking sequences in the DNA of B melitensis. The HOOF-Prints technique was used to identify wild-type and vaccine strains of B melitensis. Phylogenetic analysis of short, polymorphic fragments of DNA from B melitensis strains M5 and M43 was performed. RESULTS Variable-number tandem repeat DNA segments of B melitensis vaccine strain M5 and wild-type strain M43 were successfully amplified by means of PCR assay. All target gene fragments ranged in size from 100 to 300 bp. Separate phylogenetic analysis of each Brucella strain revealed considerable differences between the vaccine and wild-type strains. CONCLUSIONS AND CLINICAL RELEVANCE The results of this study suggested the HOOF-Prints assay may be useful for discriminating vaccine strains of B melitensis from wild-type strains. This ability could allow discrimination between animals that are seropositive because of vaccination against B melitensis and those that are seropositive because of B melitensis infection and could decrease the likelihood of importing Brucella-infected animals.

OBJECTIVE To determine the pharmacokinetic and pharmacodynamic effects of midazolam following IV and IM administration in sheep. ANIMALS 8 healthy adult rams. PROCEDURES Sheep were administered midazolam (0.5 mg/kg) by the IV route and then by the IM route 7 days later in a crossover study. Physiologic and behavioral variables were assessed and blood samples collected for determination of plasma midazolam and 1-hydroxymidazolam (primary midazolam metabolite) concentrations immediately before (baseline) and at predetermined times for 1,440 minutes after midazolam administration. Pharmacokinetic parameters were calculated by compartmental and noncompartmental methods. RESULTS Following IV administration, midazolam was rapidly and extensively distributed and rapidly eliminated; mean ± SD apparent volume of distribution, elimination half-life, clearance, and area under the concentration-time curve were 838 ± 330 mL/kg, 0.79 ± 0.44 hours, 1,272 ± 310 mL/h/kg, and 423 ± 143 h·ng/mL, respectively. Following IM administration, midazolam was rapidly absorbed and bioavailability was high; mean ± SD maximum plasma concentration, time to maximum plasma concentration, area under the concentration-time curve, and bioavailability were 820 ± 268 ng/mL, 0.46 ± 0.26 hours, 1,396 ± 463 h·ng/mL, and 352 ± 148%, respectively. Respiratory rate was transiently decreased from baseline for 15 minutes after IV administration. Times to peak sedation and ataxia after IV administration were less than those after IM administration. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated midazolam was a suitable short-duration sedative for sheep, and IM administration may be a viable alternative when IV administration is not possible.

The aim of this case series was to describe the differences between maternal and fetal blood-gas results during anesthesia. Sixteen singleton adult merino ewes weighing 60.1 ± 5.1 kg at 125.7 d (124 to 126 d) gestation were anesthetized. Maternal (radial) and fetal (umbilical) arterial blood gas samples were collected 79 ± 6 min after the start of anesthesia if maternal mean arterial pressure (MAP) was stable and > 65 mmHg. Fetal pH, partial arterial pressure of oxygen (PaO2), glucose, arterial hemoglobin oxygen saturation (SaO2), sodium, and chloride were significantly lower and fetal partial arterial pressure of carbon dioxide (PaCO2), lactate, hematocrit, total hemoglobin, potassium, and calcium were significantly higher than maternal blood-gas values. Fetal pH, PaO2, and BE were lower and fetal lactate was higher than fetal umbilical arterial samples previously reported, which may indicate a non-reassuring fetal status. Further refinement of the ovine experimental model is warranted with fetal monitoring during maternal anesthesia.

There are few reports investigating the characterization of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in dogs in Canada and none from Atlantic Canada. The objectives of this study were to strain type MRSP isolates cultured at a regional diagnostic laboratory using direct repeat unit (dru) typing and to describe their antimicrobial resistance profiles. Ninety-four isolates recovered from dogs between 2010 and 2012 had dru typing, cluster analysis, and antimicrobial susceptibility testing done. The majority of isolates belonged to type dt11a (30.9%), dt10h (24.5%), dt9a (18.1%), and dt11af (10.6%) with the remaining 15.9% of isolates distributed among 13 dru types. The predominant dru types identified were similar in Ontario; however, cluster 9a appears to be less common in Atlantic Canada. A significant difference in the distribution of clusters among Atlantic provinces was detected (P = 0.01). Resistance to ≥ 2 non-β-lactam antimicrobials was observed in 71.4% of the isolates. The MRSP isolates from this study were notably less resistant than those reported in the literature. A more comprehensive study of the MRSP dru types could help further elucidate the distribution of this pathogen in Canada.

OBJECTIVE To develop a noninvasive biomarker-based detection system specific for Mycobacterium bovis for monitoring infection in wild animals. SAMPLE Serum samples from 8 experimentally infected yearling white-tailed deer (Odocoileus virginianus) and 3 age-matched control deer and from 393 Minnesota Department of Natural Resources hunter-harvested white-tailed deer in northwest Minnesota. PROCEDURES 8 yearling deer were inoculated with 2 × 10(8) CFUs of virulent M bovis strain 1315 (day 0), and sera were obtained on days 0, 19, 48, and 60; sera were obtained from 3 uninoculated control deer on those same days. Sera from these deer and 9 M bovis-positive hunter-harvested deer were tested for 3 Mycobacterium-specific biomarkers (MB1895c, MB2515c, and polyketide synthase 5) by use of an indirect ELISA. That same ELISA was used to test sera obtained from 384 exposed noninfected deer in northwest Minnesota from 2007 through 2010, concurrent with an outbreak of tuberculosis involving cattle and deer in that region. RESULTS ELISA results revealed that tuberculosis infection could be detected as early as 48 days after inoculation in experimentally infected deer. Results for 384 deer sera revealed that prevalence of tuberculosis decreased over the 4-year period. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the prevalence of tuberculosis in Minnesota deer decreased after 2009 but tuberculosis may have persisted (as subclinical disease) at extremely low levels, as indicated by the presence of low concentrations of circulating biomarkers. Biomarker-based diagnostic tests may offer a specific approach for early identification of M bovis infection.

The objective of this study was to investigate whether cleaning surgical materials used to close pelvic flexure enterotomies with a wet sterile gauze will reduce contamination and whether the use of a full thickness appositional suture pattern (F) or a partial thickness inverting (or Cushing) suture pattern (C) would make a difference in the level of contamination. Large colon specimens were assigned to group F or C and divided into subgroups N and G. In group G, a wet sterile gauze was passed over the suture material, another over the instruments, and another over the gloves. In group N, no treatment was applied. The bacterial concentration was measured by optical density (OD) at 24 h. The OD of subgroup CG was lower than that of subgroup CN (P = 0.019). The OD of subgroup FG was lower than that of subgroup FN (P = 0.02). The OD of subgroups CG, CN, FG, and FN was lower than that of the negative control (P < 0.003, P < 0.001, P < 0.001, and P < 0.00). The use of a sterile wet gauze significantly reduced contamination of suture materials. A partial thickness inverting suture pattern did not produce less contamination than a full thickness appositional suture pattern.

OBJECTIVE To assess the effects of sedation on results of acoustoelastography of the superficial digital flexor tendons (SDFTs) in clinically normal horses. ANIMALS 27 clinically normal horses. PROCEDURES For each horse, the pathology index (PI) for the SDFT of each thoracic limb was determined by use of acoustoelastography at 4 locations (5, 10, 15, and 20 cm distal to the accessory carpal bone). Horses were evaluated before and after they were sedated with a combination of detomidine hydrochloride (0.01 mg/kg, IV) and butorphanol tartrate (0.01 mg/kg, IV). A repeated-measures ANOVA was used for statistical analysis. RESULTS Overall, the PI was lower after sedation than before sedation. In addition, the PI was lower at more distal locations than at more proximal locations. There was not a significant effect of limb (left or right). Differences among individual horses accounted for the largest variance effect. CONCLUSIONS AND CLINICAL RELEVANCE Sedation with detomidine and butorphanol facilitated acoustoelastography; however, it decreased the SDFT PI in clinically normal horses and should be used consistently in prospective studies. Variance associated with each individual horse in the sample population had the greatest effect on the PI.

OBJECTIVE To compare ammonia concentrations in arterial blood, venous blood, and CSF samples of dogs with and without extrahepatic portosystemic shunts (EHPSS). ANIMALS 19 dogs with congenital EHPSS and 6 healthy control dogs. PROCEDURES All dogs underwent a physical examination and then were anesthetized for transsplenic portal scintigraphy to confirm the presence or absence of EHPSS. While dogs were anesthetized, arterial and venous blood samples and a CSF sample were simultaneously collected for determination of ammonia concentration, which was measured by use of a portable blood ammonia analyzer (device A) and a nonportable biochemical analyzer (device B). Results were compared between dogs with EHPSS and control dogs. RESULTS Arterial, venous, and CSF ammonia concentrations for dogs with EHPSS were significantly greater than those for control dogs. For dogs with EHPSS, ammonia concentrations in both arterial and venous blood samples were markedly increased from the reference range. There was a strong positive correlation between arterial and venous ammonia concentrations and between blood (arterial or venous) and CSF ammonia concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that blood and CSF ammonia concentrations in dogs with EHPSS were greater than those for healthy dogs and were strongly and positively correlated, albeit in a nonlinear manner. This suggested that the permeability of the blood-brain barrier to ammonia may be abnormally increased in dogs with EHPSS, but further investigation of the relationship between blood or CSF ammonia concentration and clinical signs of hepatic encephalopathy or the surgical outcome for dogs with EHPSS is warranted.