OBJECTIVE To assess the in vitro and in vivo platelet function of healthy dogs during administration of a low-dose aspirin regimen. ANIMALS 16 dogs. PROCEDURES Dogs received aspirin (1 mg/kg, PO, q 24 h) for 7 days. Blood and urine samples were collected before (day 1; baseline) and on days 3 and 7 of the low-dose aspirin regimen. Platelet function was evaluated by use of turbidimetric and conventional impedance aggregometry, multiple-electrode impedance aggregometry, a platelet function analyzer (PFA), and determination of urine 11-dehydro-thromboxane B2 concentration. Turbidimetric aggregometry results were compared with the results obtained by the other 4 methods. Fourteen days after cessation of aspirin, platelet-rich plasma was incubated with acetylsalicylic acid and platelet function was assessed by turbidimetric aggregometry to determine whether this technique could accurately identify dogs that responded to the low-dose aspirin regimen. RESULTS Of the 16 dogs, 13 had turbidimetric and conventional impedance aggregometry results that were decreased by > 25% from baseline on days 3 and 7, and 4 and 7 dogs had PFA closure times > 300 seconds on days 3 and 7, respectively. The median urine 11-dehydro-thromboxane B2 concentration–to–creatinine concentration ratio decreased by 49% between days 1 and 7. Turbidimetric aggregometry results were correlated with conventional impedance aggregometry results. There was poor agreement between the turbidimetric aggregometry and PFA results. The multiple-electrode impedance aggregometry protocol failed to reliably detect aspirin-induced platelet dysfunction. In vitro incubation of platelet-rich plasma with acetylsalicylic acid followed by turbidimetric aggregometry did not predict whether dogs responded to the low-dose aspirin regimen. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the response to a low-dose aspirin regimen varied among healthy dogs.

OBJECTIVE To determine effects of 2 tiludronate administration protocols on measures of lameness in horses with navicular syndrome (NS). ANIMALS 12 horses with bilateral forelimb NS. PROCEDURES Horses were randomly assigned to receive tiludronate (1 mg/kg), diluted in 5 L of isotonic electrolyte solution and delivered through a jugular vein catheter (systemic treatment group; n = 6), or tiludronate (0.1 mg/kg), diluted with saline (0.9% NaCl) solution to a total volume of 35 mL and delivered into the lateral digital vein of each forelimb with an IV regional limb perfusion (IVRLP) technique (IVRLP group; 6). Mean peak vertical ground reaction force (pVGRF) measured with a stationary force plate and subjective lameness scores (SLSs) were recorded before (day −1) and at predetermined time points after tiludronate administration on day 0. Mean pVGRFs (standardized as percentage body weight of force) and mean SLSs for the most lame forelimb and for both forelimbs of horses in each group were compared with day −1 values to determine treatment effect. RESULTS Mean pVGRF for both forelimbs and for the most lame forelimbs of systemically treated horses were significantly increased on days 120 and 200, compared with day −1 results. No significant difference in mean pVGRF was observed for IVRLP-treated horses. The SLSs were not improved at any time point following systemic treatment and were improved only on day 120 following IVRLP. CONCLUSIONS AND CLINICAL RELEVANCE Tiludronate (1 mg/kg, IV) as a single systemic treatment appeared to be beneficial for horses with NS, but no horses were judged as sound during the study period. Additional research on IVRLP with tiludronate is needed before this method can be recommended.

OBJECTIVE To measure the minimal joint space width (mJSW) in caudocranial radiographic views of orthopedically normal femorotibial joints of horses, to compare the accuracy of measurements with those of a software program designed for humans, and to identify the ideal caudocranial radiographic projection angle for mJSW measurement. ANIMALS 12 healthy mares (22 femorotibial joints) and 3 equine cadavers (6 stifle joints). PROCEDURES Caudocranial views of femorotibial joints were acquired in the proximodistal plane at 5°, 10°, and 15° (caudo-5°-proximal-craniodistal oblique, 10°, and 15°) and lateromedial plane (caudo-10°-proximo-5°-lateral-craniodistomedial oblique and caudo-10°-proximo-5°-medial-craniodistolateral oblique). The mJSWs of medial and lateral femorotibial joint compartments were measured manually by 2 evaluators and automatically by a digital analysis software program. Interevaluator reproducibility was assessed. Post hoc tests were used to identify the projection angle that provided the largest measurements. Validation of mJSW measurements was performed by evaluation of 6 stifle joints ex vivo. RESULTS Excellent agreement was achieved between the 2 evaluators and between the veterinary radiologist and the analysis software for the medial and lateral compartments of femorotibial joints. Angle of caudocranial view in the proximodistal but not lateromedial plane had a significant effect on the medial compartment mJSW measurements. Mean mJSW for the medial compartment was significantly higher for the caudoproximal-craniodistal oblique projection made at 10° from the horizontal than for other angles. Angle had no significant effect on mean mJSW for the lateral compartment. Agreement between automated measurements of mJSW in the medial compartment and thickness of nonmineralized cartilage in histologic preparations of associated tissues was excellent. CONCLUSIONS AND CLINICAL RELEVANCE Measurements of mJSW in the medial compartment of femorotibial joints, the most common site of osteoarthritis in horses, were reproducible and optimal with a caudoproximal-craniodistal oblique radiographic projection made at 10° from the horizontal.

OBJECTIVE To evaluate adherence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) to 5 suture materials commonly used in small animal surgery. SAMPLE 10 epidemiologically unrelated MRSP isolates (obtained from dogs with clinical infections) that had strong biofilm-forming ability and 5 types of suture. PROCEDURES The 5 types of suture evaluated were monofilament polyglecaprone 25, monofilament polydioxanone, triclosan-coated (TC)–monofilament polydioxanone, braided polyglactin 910, and barbed monofilament polydioxanone. Suture segments were incubated in standard suspensions of MRSP for 2 minutes. Segments were then placed in tryptone soy broth and incubated overnight. After incubation, segments were rinsed with PBS solution and sonicated to dislodge adherent bacteria. Resulting suspensions were used to create serial dilutions that were plated, incubated overnight, and counted the following day. Bacterial adherence to 1 segment of each suture type was assessed by use of scanning electron microscopy. RESULTS There was significantly less adherence of MSRP to TC–monofilament polydioxanone than to polyglecaprone 25, polyglactin 910, barbed monofilament polydioxanone, and monofilament polydioxanone. There was significantly less adherence of MSRP to polyglecaprone than to polyglactin 910. CONCLUSIONS AND CLINICAL RELEVANCE Barbed suture had a bacterial adherence profile comparable to that for monofilament suture. Adherence of MRSP was greatest for braided polyglactin 910. Use of TC–monofilament polydioxanone can be considered for patients that are at high risk of developing surgical site infections and for which a surgeon chooses a multifilament suture.

OBJECTIVE To determine serum and tissue concentrations of gallium (Ga) after oral administration of gallium nitrate (GaN) and gallium maltolate (GaM) to neonatal calves. ANIMALS 8 healthy neonatal calves. PROCEDURES Calves were assigned to 1 of 2 groups (4 calves/group). Gallium (50 mg/kg) was administered as GaN or GaM (equivalent to 13.15 mg of Ga/kg for GaN and 7.85 mg of Ga/kg for GaM) by oral gavage once daily for 5 days. Blood samples were collected 0, 0.25, 0.5, 1, 2, 4, 8, 12, and 24 hours after Ga administration on day 1; 4 and 24 hours after Ga administration on days 2, 3, and 4; and 4, 12, and 24 hours after Ga administration on day 5. On day 6, calves were euthanized and tissue samples were obtained. Serum and tissue Ga concentrations were measured by use of mass spectrometry. RESULTS Data were adjusted for total Ga dose, and comparisons were made between the 2 groups. Calves receiving GaM had a significantly higher dose-adjusted area under the curve and dose-adjusted maximum serum Ga concentration than did calves receiving GaN. Despite receiving less Ga per dose, calves receiving GaM had tissue Ga concentrations similar to those for calves receiving GaN. CONCLUSIONS AND CLINICAL RELEVANCE In this study, calves receiving GaM had significantly higher Ga absorption than did calves receiving GaN. These findings suggested that GaM might be useful as a prophylactic agent against Mycobacterium avium subsp paratuberculosis infection in neonatal calves.

OBJECTIVE To evaluate a percutaneous, continuous gastric decompression technique for dogs involving a temporary T-fastener gastropexy and self-retaining decompression catheter. ANIMALS 6 healthy male large-breed dogs. PROCEDURES Dogs were anesthetized and positioned in dorsal recumbency with slight left-lateral obliquity. The gastric lumen was insufflated endoscopically until tympany was evident. Three T-fasteners were placed percutaneously into the gastric lumen via the right lateral aspect of the abdomen, caudal to the 13th rib and lateral to the rectus abdominis muscle. Through the center of the T-fasteners, a 5F locking pigtail catheter was inserted into the gastric lumen and attached to a device measuring gas outflow and intragastric pressure. The stomach was insufflated to 23 mm Hg, air was allowed to passively drain from the catheter until intraluminal pressure reached 5 mm Hg for 3 cycles, and the catheter was removed. Dogs were hospitalized and monitored for 72 hours. RESULTS Mean ± SD catheter placement time was 3.3 ± 0.5 minutes. Mean intervals from catheter placement to a ≥ 50% decrease in intragastric pressure and to ≤ 6 mm Hg were 2.1 ± 1.3 minutes and 8.4 ± 5.1 minutes, respectively. After catheter removal, no gas or fluid leakage at the catheter site was visible laparoscopically or endoscopically. All dogs were clinically normal 72 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE The described technique was performed rapidly and provided continuous gastric decompression with no evidence of postoperative leakage in healthy dogs. Investigation is warranted to evaluate its effectiveness in dogs with gastric dilatation-volvulus.

OBJECTIVE To determine effects of anesthesia on plasma concentrations and pulsatility of ACTH in samples obtained from the cavernous sinus and jugular vein of horses. ANIMALS 6 clinically normal adult horses. PROCEDURES Catheters were placed in a jugular vein and into the cavernous sinus via a superficial facial vein. The following morning (day 1), cavernous sinus blood samples were collected every 5 minutes for 1 hour (collection of first sample = time 0) and jugular venous blood samples were collected at 0, 30, and 60 minutes. On day 2, horses were sedated with xylazine hydrochloride and anesthesia was induced with propofol mixed with ketamine hydrochloride. Horses were positioned in dorsal recumbency. Anesthesia was maintained with isoflurane in oxygen and a continuous rate infusion of butorphanol tartrate. One hour after anesthesia was induced, the blood sample protocol was repeated. Plasma ACTH concentrations were quantified by use of a commercially available sandwich assay. Generalized estimating equations that controlled for horse and an expressly automated deconvolution algorithm were used to determine effects of anesthesia on plasma ACTH concentrations and pulsatility, respectively. RESULTS Anesthesia significantly reduced the plasma ACTH concentration in blood samples collected from the cavernous sinus. CONCLUSIONS AND CLINICAL RELEVANCE Mean plasma ACTH concentrations in samples collected from the cavernous sinus of anesthetized horses were reduced. Determining the success of partial ablation of the pituitary gland in situ for treatment of pituitary pars intermedia dysfunction may require that effects of anesthesia be included in interpretation of plasma ACTH concentrations in cavernous sinus blood.

Rotavirus B (RVB) infection in cattle is poorly understood. The objective of this study was to describe the epidemiological features of repeated outbreaks of epidemic diarrhea due to RVB infection in adult cattle on a large dairy farm complex in Japan. In October 2002, approximately 550 adult cows and approximately 450 in February 2005 had acute watery diarrhea at several farms on the complex. Four months before the first outbreak, RVB antibody-positive rates at subsequently affected farms were significantly lower than at non-affected farms (30% to 32% versus 61% to 67%). During the acute phase of both outbreaks, RVB antibody-positive rates in diarrheal cows tested were as low as 15% to 26%. Most of the farms affected in the second outbreak were also involved in the first outbreak. Some adult cows with RVB diarrhea in the first outbreak showed not only RVB seroresponse, but also RVB shedding in the second outbreak, although none of these cows developed diarrhea. Nucleotide sequences of the VP7 and VP4 genes revealed a close relationship between RVB strains in both outbreaks. Taken together, these results indicate that outbreaks of epidemic RVB diarrhea in adult cows might be influenced by herd immunity and could occur repeatedly at the same farms over several years. To our knowledge, this is the first report on repeated RVB infections in the same cattle.

OBJECTIVE To identify variations in glucose values concurrently obtained by use of a continuous glucose monitoring system (CGMS) at the same site, reliability of results for each site, lag time for each site, and influence of site thickness on CGMS accuracy. ANIMALS 8 random-source research dogs. PROCEDURES In experiment 1, 8 CGMS sensors were implanted bilaterally at 1 site (4 sensors/side) in 4 dogs. In experiment 2, 2 CGMS sensors were implanted bilaterally at each of 4 sites (1 sensor/side) in 8 dogs; 4 of those 8 dogs then were subjected to a glycemic clamp technique. The CGMS results were compared among sensors and with criterion-referenced results during periods of euglycemia for all 8 dogs and during hyperglycemia and hypoglycemia for 4 dogs during the glycemic clamp procedure. RESULTS Differences (median, −7 mg/dL; interquartile range [IQR], −18.75 to 3 mg/dL) between CGMS and criterion-referenced glucose concentrations differed significantly among dogs and sites; during euglycemia, they were not different from the expected normal variation between multiple sensors concurrently implanted at the same site. Differences (median, −35 mg/dL; IQR, −74 to −15 mg/dL) between CGMS and criterion-referenced concentrations were greater during changes in glucose concentrations. Thoracic sensors were most accurate but had the shortest mean functional life. CONCLUSIONS AND CLINICAL RELEVANCE Significant differences were detected between CGMS and criterion-referenced glucose concentrations. Overall clinical utility of CGMS was acceptable at all sites, with most of the values from all sensors, sites, and dogs meeting guidelines for point-of-care glucometers.

OBJECTIVE To develop and validate a real-time quantitative PCR (qPCR) assay for the detection and quantification of Mycoplasma ovis in goats and investigate the prevalence and risk factors for hemoplasma infection of goats located in Indiana. ANIMALS 362 adult female goats on 61 farms. PROCEDURES Primers were designed for amplification of a fragment of the dnaK gene of M ovis by use of a qPCR assay. Blood samples were collected into EDTA-containing tubes for use in total DNA extraction, blood film evaluation, and determination of PCV. Limit of detection, intra-assay variability, interassay variability, and specificity of the assay were determined. RESULTS Reaction efficiency of the qPCR assay was 94.45% (R2, 0.99; slope, −3.4623), and the assay consistently detected as few as 10 copies of plasmid/reaction. Prevalence of infection in goats on the basis of results for the qPCR assay was 18.0% (95% confidence interval, 14% to 22%), with infected goats ranging from 1 to 14 years old, whereby 61% (95% confidence interval, 47% to 73%) of the farms had at least 1 infected goat. Bacterial load in goats infected with M ovis ranged from 1.05 × 103 target copies/mL of blood to 1.85 × 105 target copies/mL of blood; however, no bacteria were observed on blood films. Production use of a goat was the only risk factor significantly associated with hemoplasma infection. CONCLUSIONS AND CLINICAL RELEVANCE The qPCR assay was more sensitive for detecting hemoplasma infection than was evaluation of a blood film, and production use of a goat was a risk factor for infection.