A study of Ontario swine farms positive for Porcine reproductive and respiratory syndrome virus (PRRSV) tested the association between genetic similarity of the virus and similarity of clinical signs reported by the herd owner. Herds were included if a positive result of polymerase chain reaction for PRRSV at the Animal Health Laboratory at the University of Guelph, Guelph, Ontario, was found between September 2004 and August 2007. Nucleotide-sequence similarity and clinical similarity, as determined from a telephone survey, were calculated for all pairs of herds. The Mantel test indicated that clinical similarity and sequence similarity were weakly correlated for most clinical signs. The generalized additive model indicated that virus homology with 2 vaccine viruses affected the association between sequence similarity and clinical similarity. When the data for herds with vaccine-like virus were removed from the dataset there was a significant association between virus similarity and similarity of the reported presence of abortion, stillbirth, preweaning mortality, and sow/boar mortality. Ownership similarity was also found to be associated with virus similarity and with similarity of the reported presence of sows being off-feed, nursery respiratory disease, nursery mortality, finisher respiratory disease, and finisher mortality. These results indicate that clinical signs of PRRS are associated with PRRSV genotype and that herd ownership is associated with both of these.

Objective—To evaluate the postoperative analgesic effects of epidural administration of morphine and neostigmine, either alone or in combination, in dogs. Animals—30 dogs undergoing orthopedic surgery on a pelvic limb. Procedures—Anesthetic protocols were standardized. At the end of surgery, 10 dogs each received 1 of 3 epidural treatments: morphine (0.1 mg/kg), neostigmine (5 μg/kg), or morphine plus neostigmine (0.1 mg/kg and 5 μg/kg, respectively). Postoperative pain scores and the need for rescue analgesia were evaluated for 24 hours. Results—Pain scores were higher in the neostigmine group, compared with scores for the morphine-neostigmine group, at 2 and 24 hours after surgery and higher in the morphine group than in the morphine-neostigmine group at 2 and 4 hours. During 24 hours, rescue analgesia was provided for 4, 7, and 2 of 10 dogs each in the morphine, neostigmine, and morphine-neostigmine groups, respectively. The number of dogs given rescue analgesia was significantly different among groups at 2, 3, 4, and 6 hours after surgery. Dogs in the morphine and morphine-neostigmine groups had a lower probability of receiving rescue analgesia within 24 hours than did dogs in the neostigmine group. Conclusions and Clinical Relevance—When administered epidurally, morphine alone or in combination with neostigmine provided effective postoperative analgesia in most dogs after orthopedic surgery, whereas neostigmine alone did not. Findings for this study suggested a potential role for neostigmine as an adjuvant for epidural analgesia in dogs undergoing orthopedic surgeries on the pelvic limbs.

Objective-To determine the usefulness of retina samples for detection of disease-associated prion protein by use of a commercially available enzyme immunoassay (EIA) intended for rapid identification of sheep and cattle with transmissible spongiform encephalopathies (TSEs). Samples-Retina, brainstem at the level of the obex, and retropharyngeal lymph node samples obtained from 15 TSE-inoculated sheep (scrapie [n = 13] or transmissible mink encephalopathy passaged through a bovid [2]); retina and brainstem samples obtained from 11 TSE-inoculated cattle (transmissible mink encephalopathy passaged through a bovid [7] or classical BSE [4]); and negative control tissue samples obtained from 2 sheep and 2 cattle that were not inoculated with TSEs. Procedures-Tissue samples were homogenized and analyzed for detection of abnormally folded disease-associated prion protein with a commercially available EIA and 2 confirmatory assays (western blot analysis or immunohistochemical analysis). Results-Retina sample EIA results were in agreement with results of brainstem sample EIA or confirmatory assay results for negative control animals and TSE-inoculated animals with clinical signs of disease. However, TSE-inoculated animals with positive confirmatory assay results that did not have clinical signs of disease had negative retina sample EIA results. Retina sample EIA results were in agreement with brainstem sample immunohistochemical results for 4 TSE-inoculated sheep with negative retropharyngeal lymph node EIA results. Conclusions and Clinical Relevance-Results of this study suggested that retina samples may be useful for rapid EIA screening of animals with neurologic signs to detect TSEs.

Objective—To compare repeatability and equivalency of measures of femoral trochlea depth and trochlear angle in red foxes (Vulpes vulpes) determined by use of radiography, ultrasonography, and digital photography of cadaver limbs. Sample—24 pelvic limbs from 12 red fox cadavers. Procedures—Cranioproximal-craniodistal oblique (skyline) and lateromedial radiographic views of the stifle joint and ultrasonographic images at 5 locations along the femoral trochlea were used in the study. Spacing of the 5 locations was determined on the basis of patellar position with the stifle joint at various caudal angles ranging from 96° to maximal extension (approx 170°). Ultrasonographic measurements were compared with those obtained at matched locations on photographs of anatomic preparations. Trochlear depth was assessed with all 3 image formats, and trochlear angle (measured between the trochlear ridges and sulcus) was assessed on radiographs and ultrasonographic images. Patellar thickness was measured on radiographs. Values obtained were compared by means of ANOVA, modified Bland-Altman plots, and repeatability testing. Results—Depth measurement repeatability was considered good for all modalities. Small but significant differences between mean ultrasonographic trochlear depth and anatomic (photographic) measurements were found at 3 locations; 95% limits of agreement for paired anatomic and ultrasonographic measurements were wide. The ratio of trochlear depth to radiographic patellar thickness was approximately 30% for all modalities. Trochlear angle measurements were more variable than trochlear depth measurements, especially in the distal aspect of the trochlea. Conclusions and Clinical Relevance—Paired anatomic and ultrasonographic measurements did not appear equivalent in this study, possibly attributable to imprecise probe location, which could limit quantitative use of ultrasonography in assessing proximal trochlear depth in a clinical setting.

Objective—To determine pharmacokinetics of marbofloxacin in water buffalo calves (Bubalus bubalis) after multiple SC administrations and to assess differences in regimen efficacy. Animals—18 healthy buffalo calves. Procedures—Calves (n = 6 calves/group) were assigned to receive marbofloxacin SC in the neck at 1 of 3 dosages (2 mg/kg, q 24 h for 6 days [regimen 1]; 4 mg/kg, q 48 h for 6 days [regimen 2]; and 4 mg/kg, q 24 h for 3 days [regimen 3]). Serum marbofloxacin concentrations were analyzed. Efficacy predictors were estimated on the basis of minimum inhibitory concentration and mutant prevention concentration reported for Pasteurella multocida and Mannheimia haemolytica. Results—Mean ± SD area under the concentration-time curve was 5.92 ± 0.40 μg•h/mL for regimen 1, which differed significantly from that for regimens 2 (14.26 ± 0.92 μg•h/mL) and 3 (14.17 ± 0.51 μg•h/mL). Mean residence time and mean elimination half-life for regimen 2 (9.93 ± 0.20 hours and 8.77 ± 0.71 hours) both differed significantly from those for regimens 1 (721 ± 0.11 hours and 5.71 ± 0.38 hours) and 3 (759 ± 0.13 hours and 737 ± 1.19 hours). Values obtained from indices for P multocida and M haemolytica had an excessively wide range because of the various degrees of antimicrobial susceptibility (low, medium, and high) of the strains. Conclusions and Clinical Relevance—Regimen 3 had the most favorable indices, and it would be conducive for owner compliance and require less handling of animals.

Objective—To compare the anesthetic efficacy and adverse effects associated with peribulbar injection of ropivacaine (1% solution) performed with and without ultrasound guidance (UG) in dogs. Animals—15 dogs without ophthalmologic abnormalities. Procedures—Each dog was sedated and anesthetized. A peribulbar injection of ropivacaine (1% solution; 0.3 mL/kg) was performed with UG in 1 eye and without UG in the contralateral eye (control). For each eye, the intraocular pressure (IOP) immediately after eye centralization and number of punctures were recorded; ophthalmic complications, postinjection corneal sensitivity (determined by Cochet-Bonnet esthesiometry), durations of the sensory and motor blockades (the latter determined as the interval to restoration of the vestibuloocular reflex, pupillary light reflex, and conjugate eye movement), and blockade quality were assessed in both eyes following anesthetic recovery. Results—Needle placement was fully visualized in 8 of the 15 eyes injected with UG. For eyes injected with or without UG, there was no difference with regard to the number of punctures, postinjection corneal sensitivity, and sensory or motor blockade duration and quality; however, restoration of conjugate eye movement occurred later in control eyes. For eyes injected with UG, mean IOP was 18.6 mm Hg, compared with 23.3 mm Hg for control eyes. Incidence of subconjunctival hemorrhage was higher for control eyes; severity of chemosis and hyperemia varied over time within both groups of eyes. Conclusion and Clinical Relevance—In dogs, peribulbar injection of ropivacaine with UG is feasible in dogs and provides effective sensory and motor blockades similar to those achieved with conventional techniques.

Objective-To evaluate intra-articular autologous protein solution (APS) for the treatment of osteoarthritis in horses. Animals-40 client-owned horses with naturally occuring osteoarthritis. Procedures-APS was generated from a dual-device system that concentrated plasma and WBC proteins and enriched platelet growth factors. Horses were randomly assigned to receive an intra-articular injection of 5 mL of saline (0.9% NaCl) solution (n = 20) or APS (20), exercised on a treadmill, and evaluated on the basis of lameness grades, kinetic gait analysis, joint circumference, and range of motion for 14 days. Horses that received saline solution were administered APS at termination of the study, and clients scored horses for lameness and discomfort before, 12 weeks after, and 52 weeks after the APS injection. Results-The APS group had significant improvements in lameness grade, asymmetry indices of vertical peak force, and range of joint motion by 14 days, compared with baseline or control group values. No adverse effects associated with APS treatment were evident. Clients assessed lameness and comfort as improved at 12 and 52 weeks. The APS had greater likelihood (OR, 4.3 to 30.0) of a therapeutic response in horses with a lameness score < 4, < 10% vertical force asymmetry, or absence of marked osteophyte formation, subchondral sclerosis, or joint space narrowing. Concentration of interleukin-1 receptor antagonist in APS was 5.8 times that in blood. Conclusions and Clinical Relevance-Intra-articular administration of APS can be considered an effective treatment option for equine osteoarthritis, with the potential for disease-modifying effects.

Objective-To use mathematical modeling to assess the effectiveness of control strategies for porcine reproductive and respiratory syndrome (PRRS) virus on a swine farm. Sample-A hypothetical small, medium, or large farrow-to-weaning swine farm in the Midwestern United States. Procedures-Stochastic models were formulated to simulate an outbreak of PRRS on a farm. Control strategies assessed in those models included none (baseline) and various combinations of mass immunization, herd closure, and gilt acclimatization. Nine different models resulting from the combination of low, moderate, or high PRRS virus virulence and small, medium, or large herd size were simulated. A stabilized status, the outcome of interest, was defined as the absence of positive PCR assay results for PRRS virus in 3-week-old piglets. For each scenario, the percentage of simulations with a stabilized status was used as a proxy for the probability of disease control. Results-Increasing PRRS virus virulence and herd size were negatively associated with the probability of achieving a stabilized status. Repeated mass immunization with herd closure or gilt acclimitization was a better alternative than was single mass immunization for disease control within a farm. Conclusions and Clinical Relevance-Repeated mass immunization with a PRRS modified-live virus vaccine with herd closure or gilt acclimitization was the scenario most likely to achieve a stabilized status. Estimation of the cost of various PRRS control strategies is necessary.

Objective-To compare bronchoalveolar lavage (BAL) fluid obtained by manual aspiration (MA) with a handheld syringe with that obtained by suction pump aspiration (SPA) in healthy dogs. Animals-13 adult Beagles. Procedures-Each dog was anesthetized and bronchoscopic BAL was performed. The MA technique was accomplished with a 35-mL syringe attached to the bronchoscope biopsy channel. The SPA technique was achieved with negative pressure (5 kPa) applied to the bronchoscope suction valve with a disposable suction trap. Both aspiration techniques were performed in each dog in randomized order on opposite caudal lung lobes. Two 1 mL/kg aliquots of warm saline (0.9% NaCl) solution were infused per site. For each BAL fluid sample, the percentage of retrieved fluid was calculated, the total nucleated cell count (TNCC) and differential cell count were determined, and semiquantitative assessment of slide quality was performed. Comparisons were made between MA and SPA techniques for each outcome. Results-1 dog was removed from the study because of illness. The mean percentage of fluid retrieved (mean difference, 23%) and median TNCC (median distribution of differences, 100 cells/μL) for samples obtained by SPA were significantly greater than those for samples obtained by MA. Conclusions and Clinical Relevance-In healthy dogs, BAL by SPA resulted in a significantly higher percentage of fluid retrieval and samples with a higher TNCC than did MA. Further evaluation of aspiration techniques in dogs with respiratory tract disease is required to assess whether SPA improves the diagnostic yield of BAL samples.

Objective-To determine ultrasonographic features and reference values of the anatomy of the abdomen of common rats (Rattus norvegicus). Animals-20 adult male and 20 adult female rats. Procedures-A complete abdominal ultrasonographic examination was performed with the rats sedated. The cadavers of 4 rats were used for anatomic comparisons. Two cadavers were dissected and 2 cadavers were frozen and then cross-sectioned by use of an electric bandsaw. Slices were cleaned with water and photographed on each side. Correlations between variables were determined. Results-The ultrasonographic anatomy of the abdomen was determined, including measurements of the kidneys and adrenal glands and thickness of the walls of the stomach (saccus caecus, fundus, and pylorus), duodenum, and cecum. A significant positive correlation between kidney size and body weight was detected. The dorsoventral measurements of the left and right adrenal gland were significantly different, regardless of sex. Dorsoventral measurements of the right adrenal gland were significantly different between males and females. Conclusions and Clinical Relevance-The ultrasonographic images and data provided an atlas of the ultrasonographic anatomy of common rats that may be useful to veterinary radiologists, clinicians, and researchers.