The present study investigated the effects of vaccinating sows and piglets or piglets alone against Haemophilus parasuis on the prevalence of H. parasuis in nasal swabs, on the humoral and cellular immune responses, and on the production parameters of piglets at 3 Korean farms with a clinical history of polyserositis caused by H. parasuis. Piglets born to vaccinated or non-vaccinated sows were subdivided into 3 groups: vaccinated sows and vaccinated pigs (VS-VP), non-vaccinated sows and vaccinated pigs (NVS-VP), and non-vaccinated sows and non-vaccinated pigs (NVS-NVP). The proportion of piglets with positive nasal swabs was significantly lower (P < 0.05) in the vaccinated animals (VS-VP and NVS-VP groups) than in the non-vaccinated animals (NVS-NVP group) at 35 and 60 d of age at the 3 farms. The overall growth performance (from 7 to 60 d of age) of the vaccinated piglets was significantly better (P < 0.05) than that of the non-vaccinated piglets at the 3 farms. Piglets in the VS-VP group had significantly higher levels (P < 0.05) of H. parasuis-specific IgG antibodies, lymphocyte proliferation, and interferon-γ-secreting cells than piglets in the NVS-VP and NVS-NVP groups on days 1, 7, 21, 35, and 60 after birth at the 3 farms.

Objective: To determine the precision of a clinical illness score (CIS) system for identification of clinical signs in calves with experimentally induced Mycoplasma bovis pneumonia and to evaluate the accuracy of CISs in relation to pulmonary consolidation scores assigned at necropsy. Animals: 178 Holstein bull calves that were 52 to 91 days of age at the time of pneumonia induction. Procedures: 5 trials involved calves challenged with M bovis and scheduled for euthanasia and necropsy 12 to 24 days afterward. Nine veterinarian observers with various degrees of experience simultaneously assigned CISs to calves within 48 hours before necropsy. The precision of the CIS system among observers was evaluated via the Cohen κ statistic. The accuracy of each observer's CISs relative to 6 cutoffs (≥ 5%, ≥ 10%, ≥ 15%, ≥ 20%, ≥ 25%, and ≥ 30%) of percentage pulmonary consolidation was determined by comparing prenecropsy CISs with the gross pulmonary consolidation scores assigned at necropsy. Estimates for sensitivity and specificity were calculated relative to the 6 pulmonary consolidation cutoffs. Results: A slight level of agreement was evident among observers (κ range, 0.10 to 0.21 for the individual trials) and overall (κ = 0.16; 95% confidence interval, 0.10 to 0.24). Median sensitivity and specificity changed with pulmonary consolidation score cutoff. Median sensitivity for all observers ranged from 81.7% to 98.9%, and median specificity ranged from 80.8% to 94.9% over all cutoff values. Conclusions and Clinical Relevance: Agreement among observers assigning CISs to calves was low; the accuracy of the CIS system in relation to that of pulmonary consolidation scoring varied with the severity of consolidation considered to represent bovine respiratory disease.

Objective: To compare the mesenchymal stem cell (MSC) yield and chondrogenic and osteogenic differentiation from 5- and 50-mL bone marrow aspirates from horses. Animals: Six 2- to 5-year-old mixed-breed horses. Procedures: 2 sequential 5-mL aspirates were drawn from 1 ilium or sternebra. A single 50-mL aspirate was drawn from the contralateral ilium, and 2 sequential 50-mL aspirates were drawn from a second sternebra. The MSC yield was determined through the culture expansion process. Chondrogenesis and osteogenesis were evaluated by means of conventional laboratory methods. Results: The second of the 2 sequential 50-mL sternal aspirates yielded few to no MSCs. Independent of location, the highest density of MSCs was in the first of the 2 sequential 5-mL fractions, although with subsequent culture expansion, the overall yield was not significantly different between the first 5-mL and first 50-mL fractions. Independent of location, chondrogenesis and osteogenesis were not significantly different among fractions. Independent of fraction, the overall cell yield and chondrogenesis from the ilium were significantly higher than that from the sternum. Conclusions and Clinical Relevance: This study failed to detect an additional benefit of 50-mL aspirates over 5-mL aspirates for culture-expanding MSCs for equine clinical applications. Chondrogenesis was highest for MSCs from ilial aspirates, although it is not known whether chondrogenesis is indicative of activation of other proposed pathways by which MSCs heal tissues.

Objective: To characterize medial femoral condyle (MFC) morphometrics and subchondral bone density patterns in Thoroughbred racehorses and to determine whether these variables differ between left and right limbs. Sample: Stifle joints harvested from 6 Thoroughbred racehorses euthanized for reasons other than hind limb lameness. Procedures: The distal portion of the left and right femurs of each cadaver was scanned via CT. Hounsfield units were converted to dipotassium phosphate equivalent densities through use of a phantom on each specimen. Medial femoral condyle width, length, height, and curvature; subchondral bone plate densities; and subchondral trabecular bone densities were analyzed in multiple sections in 5 frontal planes and 3 sagittal planes and were compared between left and right MFCs. Results: MFC width, length, and height did not differ between left and right limbs. Regions of interest in the right caudoaxial subchondral bone plate and subchondral trabecular bone were significantly denser than their corresponding left regions of interest in the frontal and sagittal planes. A concavity in the otherwise convex articular surface of the cranial aspect of the MFC was identified in 11 of 12 specimens. Conclusions and Clinical Relevance: A disparity was identified between left and right subchondral bone density patterns at the caudoaxial aspect of the MFC, which could be attributable to the repetitive asymmetric cyclic loading that North American Thoroughbred racehorses undergo as they race in a counterclockwise direction. The uneven region at the cranial aspect of the MFC could be associated with the development of subchondral bone cysts in horses.

Objective: To obtain ultrasonographic reference values for the thickness of the pancreas and the diameter of the pancreatic duct in clinically normal dogs. Animals: 242 adult dogs with no clinical signs of gastrointestinal tract disease. Procedures: The maximum pancreatic thickness and the diameter of the pancreatic duct were recorded ultrasonographically at the level of the left lobe, body, and right lobe of the pancreas. Results: Mean ± SD pancreatic thickness measurements were as follows: left lobe, 6.5 ± 1.7 mm (n = 214); body, 6.3 ± 1.6 mm (155); and right lobe, 8.1 ± 1.8 mm (239). The mean pancreatic duct diameter was 0.6 ± 0.2 mm (n = 42) in the left lobe and 0.7 ± 0.2 mm (213) in the right lobe. The right pancreatic duct was visible in 213/242 (88.0%) dogs, and the left pancreatic duct was visible in 41/242 (16.9%) dogs. However, the body was visible in only 16/242 (6.6%) dogs. Pancreatic thickness and diameter of the pancreatic duct significantly increased with body weight in all lobes, but age was not correlated with the measurements. Conclusions and Clinical Relevance: Ultrasonographic reference values for the pancreas and pancreatic duct of dogs were determined. Results of this study indicated that the pancreatic duct was visible, especially in the right lobe of the pancreas. These values may be useful for the assessment of pancreatic abnormalities, such as chronic pancreatitis and exocrine pancreatic insufficiency.

Objective: To determine the effects of topically applied 2% delta-9-tetrahydrocannabinol (THC) ophthalmic solution on aqueous humor flow rate (AHFR) and intraocular pressure (IOP) in clinically normal dogs. Animals: 21 clinically normal dogs. Procedures: A randomized longitudinal crossover design was used. Following acquisition of baseline IOP (morning and evening) and AHFR (afternoon only) data, dogs were randomly assigned to 2 treatment groups and received 1 drop of either 2% THC solution or a control treatment (olive oil vehicle) to 1 randomly selected eye every 12 hours for 9 doses. The IOPs and AHFRs were reassessed after the final treatment. Following a washout period of ≥ 7 days, dogs were administered the alternate treatment in the same eye, and measurements were repeated. Results: Mean ± SD IOPs in the morning were 15.86 ± 2.48 mm Hg at baseline, 12.54 ± 3.18 mm Hg after THC treatment, and 13.88 ± 3.28 mm Hg after control treatment. Mean ± SD IOPs in the evening were 13.69 ± 3.36 mm Hg at baseline, 11.69 ± 3.94 mm Hg after THC treatment, and 12.13 ± 2.99 mm Hg after control treatment. Mean IOPs were significantly decreased from baseline after administration of THC solution but not the control treatment. Changes in IOP varied substantially among individual dogs. Mean ± SD AHFRs were not significantly different from baseline for either treatment. Conclusions and Clinical Relevance: Topical application of 2% THC ophthalmic solution resulted in moderate reduction of mean IOP in clinically normal dogs. Further research is needed to determine efficacy in dogs with glaucoma.

Objective-To compare the efficacy of gamithromycin with that of tulathromycin for control of undifferentiated bovine respiratory disease complex (BRDC) in feedlot calves. Animals-2,529 weaned crossbred beef calves. Procedures-At each of 2 feedlots, calves at risk of developing BRDC were administered a single dose of gamithromycin (6.0 mg/kg, SC; n = 1,263) or tulathromycin (2.5 mg/kg, SC; 1,266) metaphylactically. Health (BRDC morbidity, mortality, case-fatality, and retreatment rates) and performance (average daily gain, dry matter intake, and feed-to-gain ratio) outcomes were compared between treatments via classical hypothesis testing. Bioequivalence limits for gamithromycin and tulathromycin were established for outcomes for which no significant difference between treatments was detected. Results-Mean BRDC morbidity rate (31.0%) for calves administered gamithromycin was greater than that (22.9%) for calves administered tulathromycin; otherwise, health and performance did not differ between treatments. Limits for mean differences within which gamithromycin was considered bioequivalent to tulathromycin were +/- 10% for BRDC retreatment rate, +/- 3.5% for BRDC mortality rate, ± 16% for case-fatality rate, +/- 37 kg for final body weight, +/- 0.1 kg/d for average daily gain, +/- 0.3 kg/d for dry matter intake, and +/- 0.7 for feed-to-gain ratio. Conclusions and Clinical Relevance-The efficacy of gamithromycin did not differ from that of tulathromycin for all outcomes except morbidity rate; calves administered gamithromycin had a higher BRDC morbidity rate than did calves administered tulathromycin. On the basis of the bioequivalence limits established for this dataset, gamithromycin was considered equivalent to tulathromycin for the control of BRDC.

Objective-To evaluate the duration of effects on movement patterns of horses after sedation with equipotent doses of xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride and determine whether accelerometry can be used to quantify differences among drug treatments. Animals-6 healthy horses. Procedures-Each horse was injected IV with saline (0.9% NaCl) solution (10 mL), xylazine diluted in saline solution (0.5 mg/kg), detomidine diluted in saline solution (0.01 mg/kg), or romifidine diluted in saline solution (0.04 mg/kg) in random order. A triaxial accelerometric device was used for gait assessment 15 minutes before and 5, 15, 30, 45, 60, 75, 90, 105, and 120 minutes after each treatment. Eight variables were calculated, including speed, stride frequency, stride length, regularity, dorsoventral power, propulsive power, mediolateral power, and total power; the force of acceleration and 3 components of power were then calculated. Results-Significant differences were evident in stride frequency and regularity between treatments with saline solution and each α2-adrenoceptor agonist drug; in speed, dorsoventral power, propulsive power, total power, and force values between treatments with saline solution and detomidine or romifidine; and in mediolateral power between treatments with saline solution and detomidine. Stride length did not differ among treatments. Conclusions and Clinical Relevance-Accelerometric evaluation of horses administered α2-adrenoceptor agonist drugs revealed more prolonged sedative effects of romifidine, compared with effects of xylazine or detomidine. Accelerometry could be useful in assessing the effects of other sedatives and analgesics. Accelerometric data may be helpful in drug selection for situations in which a horse's balance and coordination are important.

Objective-To evaluate the use of high-resolution manometry (HRM) in awake and sedated dogs and to assess potential effects of a standard sedation protocol. Animals-22 Beagles. Procedures-An HRM catheter with 36 pressure sensors was inserted intranasally in each dog. After an adaption period of 5 minutes, each set of measurements included 5 swallows of a liquid and 5 swallows of a solid bolus. Measurements were repeated 30 minutes after IM administration of buprenorphine and acepromazine. Results-HRM was successfully performed in 14 dogs. Data sets of 8 dogs were adequate for analysis. For the upper esophageal sphincter, median values of baseline pressure, residual pressure, relaxation time to nadir, and relaxation duration were determined for awake and sedated dogs for liquid and solid swallows. For the tubular portion of the esophagus, median values of peristaltic contractile integral, bolus transit time, and contractile front velocity were determined for awake and sedated dogs for liquid and solid swallows. For the lower esophageal sphincter, median values of baseline pressure and residual pressure were determined for awake and sedated dogs for liquid and solid swallows. Significant differences (awake vs sedated) were found for the upper esophageal sphincter residual pressure (liquid swallows), relaxation time to nadir (liquid swallows), bolus transit time (solid swallows), and contractile front velocity (solid swallows). Conclusions and Clinical Relevance-HRM was feasible for evaluation of esophageal function in most awake dogs. Although sedation in uncooperative patients may minimally influence results of some variables, an overall assessment of swallowing should be possible.