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.

The objective of this study was to compare the protection against challenge with porcine circovirus 2 (PCV2) induced by an experimental vaccine based on open reading frame (ORF) 2 of PCV2 DNA plus an adjuvant (aluminum hydroxide, cobalt oxide, or liposome) and a commercial PCV2 subunit vaccine. A total of 35 colostrum-fed, cross-bred, conventional piglets were randomly divided into 7 groups. The commercial vaccine was more efficacious against PCV2 challenge than the 4 experimental vaccines according to immunologic, virologic, and pathological outcomes. The pigs inoculated with the experimental vaccine containing the liposome adjuvant had significantly higher levels (P < 0.05) of neutralizing antibodies and interferon-γ-secreting cells, and significantly lower levels (P < 0.05) of PCV2 viremia than the pigs inoculated with the other experimental vaccines. The pigs inoculated with the experimental vaccines containing either the liposome adjuvant or the cobalt oxide adjuvant had significantly lower lymphoid lesion scores (P < 0.05) than the pigs in the group inoculated with the PCV2 DNA vaccine dissolved in phosphate-buffered saline. Liposome proved to be a potent adjuvant that efficiently enhanced both humoral and cellular immune responses induced by the PCV2 DNA vaccine.

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.

OBJECTIVE To measure immunologic responses of snakes after experimentally induced infection with ferlaviruses. ANIMALS 42 adult corn snakes (Pantherophis guttatus) of both sexes. PROCEDURES Snakes were inoculated intratracheally with genogroup A (n = 12), B (12), or C (12) ferlavirus (infected groups) or cell-culture supernatant (6; control group) on day 0. Three snakes from each infected group were euthanized on days 4, 16, 28, and 49, and 3 snakes from the control group were euthanized on day 49. Blood samples were collected from live snakes on days −6 (baseline), 4, 16, 28, and 49. Hematologic tests were performed and humoral responses assessed via hemagglutination-inhibition assays and ELISAs. Following euthanasia, gross pathological and histologic evaluations and virus detection were performed. RESULTS Severity of clinical signs of and immunologic responses to ferlavirus infection differed among snake groups. Hematologic values, particularly WBC and monocyte counts, increased between days 4 and 16 after infection. A humoral response was identified between days 16 and 28. Serum IgM concentrations increased from baseline earlier than IgY concentrations, but the IgY relative increase was higher at the end of the study. The hemagglutination-inhibition assay revealed that the strongest reactions in all infected groups were against the strain with which they had been infected. Snakes infected with genogroup A ferlavirus had the strongest immune response, whereas those infected with genogroup B had the weakest responses. CONCLUSIONS AND CLINICAL RELEVANCE Results of this experimental study suggested that the ferlavirus strain with the highest virulence induced the weakest immune response in snakes.

Porcine parvoviruses (PPV) are known to be particularly resistant to many disinfectants used to control other non-enveloped viruses. However, effective disinfectants used against PPV are harsh and corrosive to animal health facilities and the environment. We propose a noncorrosive "green" disinfectant that generates peracetic acid in-situ and is capable of inactivating PPV completely at a 1% concentration for a 10-minute contact time.

OBJECTIVE To evaluate a method for identifying intact and degranulated eosinophils in the small intestine of dogs with inflammatory bowel disease (IBD) by use of a monoclonal antibody (mAb) against eosinophil peroxidase (EPX). ANIMALS 11 untreated dogs with IBD, 5 dogs with IBD treated with prednisolone, and 8 control dogs with no clinical evidence of gastrointestinal tract disease and no immunosuppressive treatment. PROCEDURES 4-μm-thick sections of paraffin-embedded tissues from necropsy specimens were immunostained with EPX mAb. Stained intact and degranulated eosinophils in consecutive microscopic fields (400X magnification) of the upper (villus tips) and lower (between the muscularis mucosae and crypts) regions of the lamina propria of the jejunum were manually counted. RESULTS Compared with control and treated IBD dogs, untreated IBD dogs had a significantly higher number of degranulated eosinophils in the lower region of the lamina propria. However, no significant differences were detected in the number of intact eosinophils in this region among groups. In the upper region of the lamina propria, untreated IBD dogs had a significantly higher number of degranulated and intact eosinophils, compared with control and treated IBD dogs. Number of degranulated and intact eosinophils did not differ significantly between control and treated IBD dogs. CONCLUSIONS AND CLINICAL RELEVANCE Immunohistologic analysis with EPX mAb yielded prominent granule staining that allowed reliable morphological identification of degranulated and intact eosinophils, which may provide a strategy for quantitative and selective evaluation of eosinophils in gastrointestinal biopsy specimens and a potential method to diagnose IBD and evaluate treatment outcome.

OBJECTIVE To examine effects of continuous rate infusion of lidocaine on transmural neutrophil infiltration in equine intestine subjected to manipulation only and remote to ischemic intestine. ANIMALS 14 healthy horses. PROCEDURES Ventral midline celiotomy was performed (time 0). Mild ischemia was induced in segments of jejunum and large colon. A 1-m segment of jejunum was manipulated by massaging the jejunal wall 10 times. Horses received lidocaine (n = 7) or saline (0.9% NaCl) solution (7) throughout anesthesia. Biopsy specimens were collected and used to assess tissue injury, neutrophil influx, cyclooxygenase expression, and hypoxia-inducible factor 1α (HIF-1α) expression at 0, 1, and 4 hours after manipulation and ischemia. Transepithelial resistance (TER) and mannitol flux were measured by use of Ussing chambers. RESULTS Lidocaine did not consistently decrease neutrophil infiltration in ischemic, manipulated, or control tissues at 4 hours. Lidocaine significantly reduced circular muscle and overall scores for cyclooxygenase-2 expression in manipulated tissues. Manipulated tissues had significantly less HIF-1α expression at 4 hours than did control tissues. Mucosa from manipulated and control segments obtained at 4 hours had lower TER and greater mannitol flux than did control tissues at 0 hours. Lidocaine did not significantly decrease calprotectin expression. Severity of neutrophil infiltration was similar in control, ischemic, and manipulated tissues at 4 hours. CONCLUSIONS AND CLINICAL RELEVANCE Manipulated jejunum did not have a significantly greater increase in neutrophil infiltration, compared with 4-hour control (nonmanipulated) jejunum remote to sites of manipulation, ischemia, and reperfusion. Lidocaine did not consistently reduce neutrophil infiltration in jejunum.

OBJECTIVE To assess effects of major abdominal surgery on serum cortisol and aldosterone and plasma canine ACTH (cACTH) concentrations. ANIMALS 39 healthy dogs undergoing laparotomy during veterinary student surgical laboratories. PROCEDURES Blood samples were obtained before and at completion of surgery. Serum cortisol and aldosterone and plasma cACTH concentrations were measured by use of validated radioimmunoassays. Changes in concentrations (postoperative concentration minus preoperative concentration) were calculated. Data were analyzed by use of the Wilcoxon signed rank test, Pearson correlation analysis, and Mann-Whitney rank sum test. RESULTS Cortisol, aldosterone, and cACTH concentrations increased significantly from before to after surgery. Although cortisol and aldosterone concentrations increased in almost all dogs, cACTH concentrations decreased in 6 of 32 (19%) dogs. All dogs had preoperative cortisol concentrations within the reference range, but 24 of 39 (62%) dogs had postoperative concentrations above the reference range. A correlation between the change in cACTH concentration and the change in cortisol concentration was not detected. CONCLUSIONS AND CLINICAL RELEVANCE Laparotomy caused a significant increase in serum cortisol and aldosterone concentrations. In most dogs, but not all dogs, plasma cACTH concentrations increased. Lack of correlation between the change in cACTH concentration and the change in cortisol concentration suggested that increased postoperative cortisol concentrations may have been attributable to ACTH-independent mechanisms, an early ACTH increase that caused a sustained cortisol release, or decreased cortisol clearance. Further studies are indicated to evaluate the effects of various anesthetic protocols and minimally invasive surgical techniques on the stress response.