Pharmacokinetics of sulfamethazine in male, female and castrated male swine

The concentration of sulfamethazine in plasma and sulfamethazine and its metabolites in urine were compared in male, female and castrated male swine. A surgical technique for placement of catheters in the urinary bladder was used to facilitate the collection of urine in males and castrated males. The elimination rate of sulfamethazine from plasma and the excretion of parent drug and metabolites into urine did not differ significantly among females, males and castrated male swine.     

Age, Tibial Plateau Angle, Sex, and Weight as Risk Factors for Contralateral Rupture of the Cranial Cruciate Ligament in Labradors

Objective— To compare rates of contralateral cranial cruciate ligament rupture (CCLR) in Labradors based on age and weight at initial rupture, sex, and tibial plateau angle (TPA) and to determine whether Labradors that rupture their initial cranial cruciate ligament (CCL) at an earlier age (<4 years) are more likely to rupture their contralateral side within a certain period of time. Study Design— Case series. Animals— Labradors (n=94) that had tibial plateau leveling osteotomy (TPLO). Methods— Two groups: no contralateral rupture (NR) and contralateral rupture (CR) were compared for significant (P<.05) differences in percentage of subsequent cruciate tears using a Wilcoxon's rank‐sum tests for continuous variables and Fisher's exact test for sex. Adjusted odds ratios for likelihood of subsequent cruciate tears (yes/no) were estimated using logistic regression. Associations of these characteristics with time to subsequent rupture were assessed using Kaplan–Meier survival analysis estimation. Predictors of presentation with bilateral ruptures (BR) versus single rupture were also evaluated using Wilcoxon's rank‐sum tests and a generalized Fisher's exact test. Results— Subsequent CCLR occurred in 45 dogs (48%), and BR on admission were identified in 10 dogs (10.6%). Comparing NR and CR dogs, there were no significant differences between age or weight at initial rupture, sex or TPA; however there were associations toward longer time to CR for dogs older than the median age and female dogs (intact and spayed). There were no significant differences in age, sex, weight, or TPA of dogs with bilateral CCL ruptures compared with initial unilateral ruptures; however, there was a trend toward dogs presenting at an older age and with lower TPA's in the BR group. Among the 84 NR/CR dogs, the median time to rupture of the contralateral CCL was 5.5 months (95% CI 5.2–5.7). Conclusions— Age and weight at initial rupture, sex, and TPA does not affect likelihood or rate of contralateral CCL rupture or presentation with bilateral CCL ruptures. Clinical Relevance— Approximately 50% of Labradors will rupture the contralateral CCL within 5.5 months of the initial rupture but age, weight, sex, and TPA cannot be used as predictive features.     

Ex Vivo Biomechanical Comparison of the 2.4 mm UniLOCK® Reconstruction Plate Using 2.4 mm Locking Versus Standard Screws for Fixation of Acetabular Osteotomy in Dogs

Objective— To compare the accuracy of reduction and the biomechanical characteristics of canine acetabular osteotomies stabilized with locking versus standard screws in a locking plate. Study Design— Ex vivo biomechanical study. Sample Population— Cadaveric canine hemipelves and corresponding femurs (n=10 paired). Methods— Transverse acetabular osteotomies stabilized with 5‐hole 2.4 mm uniLOCK^® reconstruction plates using either 2.4 mm locking monocortical or standard bicortical screw fixation (Synthes^® Maxillofacial). Fracture reduction was assessed directly (craniocaudal acetabular width measurements and gross observation) and indirectly (impression casts). All constructs were fatigue‐tested, followed by acute destructive testing. All outcome measures (mean±SD) were evaluated for significance (P<.05) using paired t‐tests. Results— Craniocaudal acetabular diameters before and after fixation were not significantly different (21.9±1.2 and 21.5±1.2 mm; P=.45). No significant differences were observed in acetabular width differences between pre‐ and postoperative fixation between groups (locking ?0.4±0.4 mm; standard ?0.4±0.3 mm; P=.76). Grossly, there was no significant difference in the repairs and impression casts did not reveal a significant (P=.75) difference in congruency between the groups. No significant differences were found in fracture gap between groups either dorsally (locking 0.38±0.23 mm versus standard 0.22±0.05 mm; P=.30) or ventrally (locking 0.80±0.79 mm versus standard 0.35±0.13 mm; P=.23), and maximum change in amplitude dorsally (locking 0.96±2.15 mm versus standard 0.92±0.89 mm; P=.96) or ventrally (locking 2.02±2.93 mm versus standard 0.15±0.81 mm; P=.25). There were no significant differences in stiffness (locking 241±46 N/mm versus standard 283±209 N/mm; P=.64) or load to failure (locking 1077±950 N versus standard 811±248 N; P=.49). Conclusion— No significant differences were found between pelves stabilized with locking monocortical screw fixation or standard bicortical screw fixation with respect to joint congruity, displacement of fracture gap after cyclic loading, construct stiffness, or ultimate load to failure. Clinical Relevance— There is no apparent advantage of locking plate fixation over standard plate fixation of 2‐piece ex vivo acetabular fractures using the 2.4 mm uniLOCK^® reconstruction plate.     

Fine‐scale movements of the swordfish Xiphias gladius in the Southern California Bight

This study reports on the fine‐scale movements of swordfish (Xiphias gladius) outfitted with pop‐off satellite archival transmitters (PSATs) in the Southern California Bight (SCB). PSATs were deployed on basking swordfish using traditional harpoon methods from 2004 to 2006. Transmitters were programmed for short‐term deployment (2–90 days) and re‐acquired using a signal direction finder. High‐resolution (min^?1) depth and temperature data from nine swordfish (approximately 45–120 kg) were collected (>193 days). All swordfish displayed diurnal vertical movements similar to those reported for other geographic locations. The dominant diurnal movement pattern entailed swordfish remaining below the thermocline (>68 ± 15 m) during the day and near the surface, within the upper‐mixed layer, at night. Collectively, the average daytime depth (±SE) was 273 ± 11 m and the average night depth 31 ± 5 m. Three distinct vertical behaviors were recorded: 35% of the records following a strict diurnal pattern, with the entire day below the thermocline and the entire night near the surface; 52% of the records revealed routine surface‐basking events during the day, with an otherwise similar distribution at night; and 13% of the records exhibited surface‐oriented activity during the day and night. Surface basking (<3 m during the day) was recorded for eight individuals and occurred on 131 of the 193 days (68% of the dataset). Collectively, surface basking accounted for 8% of the total daytime records. The relevance of these vertical behaviors to SCB fisheries is discussed.     

Comparison of Alternate and Simultaneous Tensioning of Wires in a Single-Ring Fixator Construct

Objective— To measure and compare the strain of wires tensioned with alternate (ALT) and simultaneous (SIM) tensioning in a single-ring fixator construct and compare the stiffness of these constructs under axial loading.
Study Design— Experimental mechanical study.
Sample Population— Twenty-four, 84 mm diameter, single-ring constructs.
Methods— Twenty-four, 84 mm diameter, single-ring constructs were assembled using 2 1.6 mm wires placed at a 60° angle tensioned with either ALT or SIM technique to 90 kg tension. Voltage data from a strain gauge were recorded during the wire-tensioning process, cyclic axial loading, and load-to-failure testing. Wire strains were calculated for each wire and compared within constructs and between ALT and SIM groups. Construct stiffness was compared between groups.
Results— There was no difference between the tensioning methods in final wire strains after initial tensioning for both the wire below the ring (W1; P =.698) and the wire above the ring (W2; P =.233). There was also no difference in final wire strains within each tensioning method group (ALT, P =.289; SIM, P =.583). Loss of wire strain (3.5–5%) occurred after cyclic loading for both wires in both groups. There was no difference in construct stiffness between the ALT and SIM groups ( P =.126). Mode of failure was by wire breakage in all constructs and occurred most frequently in W1.
Conclusion— ALT tensioning of wires produced similar wire strains within a single-ring construct after initial tensioning to SIM tensioned wires. There was no difference in construct stiffness under axial loading between AIM and SIM tensioned constructs.
Clinical Relevance— ALT tensioning of wires in a single-ring fixator construct can be used as an alternative to SIM tensioning, as similar initial wire tensions are achieved.     

RADIOGRAPHIC APPEARANCE OF CONFIRMED PULMONARY LYMPHOMA IN CATS AND DOGS

Herein we describe the thoracic radiographic appearance of confirmed pulmonary lymphoma. Patients with thoracic radiographs and cytologically or histologically confirmed pulmonary lymphoma were sought by contacting American College of Veterinary Radiology members. Seven cats and 16 dogs met the inclusion criteria, ranging in age from 4 to 15 years. Method of diagnosis was via ultrasound‐guided cytology (four), surgical biopsy (two), ultrasound‐guided biopsy (one), and necropsy (16). Radiographic findings varied but ranged from normal (one) to alveolar (six) and/or unstructured interstitial infiltrates (11), nodules and/or masses (eight), and bronchial infiltrates (four). Additional thoracic radiographic findings included pleural effusion and lymphadenopathy. The results of this evaluation indicate a wide variability in thoracic radiographic abnormalities in cats and dogs with pulmonary lymphoma.     

SMOOTH MUSCLE NEOPLASIA OF THE URINARY BLADDER WALL IN THREE DOGS

Smooth muscle origin neoplasia of the urinary bladder wall is rare in dogs. This report describes the ultrasonographic features of two bladder wall leiomyomas and one bladder wall leiomyosarcoma. All three dogs had a single, smoothly marginated, round, hypo to mixed echogenicity intraluminal mass in the urinary bladder. Based on color Doppler examination of the masses, there was no visible blood flow.     

The indirect estimation of the digestibility in cattle of herbage from Belgian permanent pasture

Relationships between herbage organic matter digestibility measured in vivo , and faecal nitrogen concentration were determined. Measurements of in vivo digestibility were made on twenty-nine herbages, cut from mixed improved permanent pastures with Lolium perenne as the predominant grass and offered ad libitum to cattle. The faecal nitrogen index predicted the herbage digestibility with good accuracy, and the equations obtained should have application for such determinations on Belgian pastures.