A cross-sectional pilot study to estimate the prevalence of and risk factors for leptospirosis in South-Western Victorian dairy herds, 2017

Leptospirosis is a zoonosis, found worldwide, affecting many species of animals. We conducted a cross-sectional study to estimate the prevalence of Leptospira borgpetersenii sv Hardjo and Leptospira interrogans sv Pomona in cattle in dairy herds in South-Western Victoria, Australia. Fifty-three herds were enrolled in the study. Urine samples were collected from 15 late-lactation cows in each herd. A questionnaire was provided to herd managers at the time of each herd visit, asking them to describe the methods they used for controlling leptospirosis, including vaccination. Urine samples were pooled at the herd level and tested for leptospira spp. using real time PCR. Urine samples from individual cows within the positive pooled samples were then tested for Leptospira Hardjo and Leptospira Pomona using qPCR. Four of the 53 herds showed positive leptospirosis results giving an apparent prevalence of 8 (95% CI 2–18) leptospira-positive herds per 100 herds at risk. Based on the 53 completed questionnaires, leptospirosis vaccination programs were not compliant with label directions in 36 of the 52 vaccinated herds: 69 (95% CI 55–81) of 100 herd managers that routinely vaccinated for leptospirosis did not comply with label directions. One herd was completely unvaccinated. Based on our findings, we estimate that approximately 10% of dairy farms in South-Western Victoria are likely to be infected with leptospirosis. While most herds are vaccinating for leptospirosis, most are not doing so according to label directions. We conclude that herd managers need to be better educated regarding leptospirosis vaccination programs.     

ULTRASONOGRAPHIC ASSESSMENT OF METALLIC CLIP CAROTID ANASTOMOSIS IN SHEEP

The aim of this study was to use ultrasonography to assess an experimental carotid arteriotomy followed by end-to-end anastomosis in the lamb. Animals were subjected to an experimental surgical procedure consisting of a right carotid artery arteriotomy and subsequent end-to-end anastomosis with nonpenetrating metallic clips. Left side arteries were used as control. Duplex ultrasonography was performed postoperatively to assess the evolution of the experimental anastomosis. Measurements were made on the right carotid to assess blood flow, peak systolic velocity, and end diastolic velocity, as well as arterial diameter. Animals were periodically checked during the six-month postoperative period. Operated vessels appeared normal during follow up, with pulsatile movements and size similar to non operated carotid arteries. A hyperechoic band, perpendicular to the vessel main axis, was seen on the longitudinal image in operated arteries, but not in the control group. This band corresponded to the anastomosis area, where the clips were positioned. No image suggestive of thrombosis was observed in any operated artery, and blood flow was maintained through the experiment. Finally, a decrease of vessel lumen diameter was evidenced at the level of the anastomosis during the first 30 postoperative days, but it was not present after the 90th postsurgical day. Duplex ultrasonography is a useful imaging technique for the assessment of anatomical details, acoustical properties of the vascular lumen, and study of the intimal surface and vessel wall in growing arteries subjected to surgery. Metallic clips as suturing technique in arterial anastomosis allow for normal vascular growth, as shown by the evolution of flow velocity and vessel diameter.     

Modulation of Glycolysis and the Pentose Phosphate Pathway Influences Porcine Oocyte In Vitro Maturation

Glycolytic and pentose phosphate pathway (PPP) activities were modulated in porcine cumulus–oocyte complexes (COCs) during in vitro maturation (IVM) by the addition of inhibitors or stimulators of key enzymes of the pathways to elucidate their relative participation in oocyte maturation. The activities of glycolysis and PPP were evaluated by lactate production per COC and by the brilliant cresyl blue test, respectively. Glucose uptake per COC and the oocyte maturation rate were also evaluated. Lactate production, glucose uptake and the percentage of oocytes reaching metaphase II decreased in a dose‐dependent manner in the presence of the pharmacological (NaF) or the physiological (ATP) inhibitors of glycolysis (p < 0.05). The addition of the physiological stimulator of glycolysis (AMP) caused no effect on lactate production, glucose uptake or the meiotic maturation rate. The pharmacological (6‐AN) and the physiological (NADPH) inhibitors of PPP induced a dose‐dependent decrease in the percentage of oocytes with high PPP activity and in the nuclear maturation rate (p < 0.05). The physiological stimulator of PPP (NADP) caused no effect on the percentage of oocytes with high PPP activity. The glycolytic and PPP activities of porcine COCs and maturational competence of oocytes seem to be closely related events. This study shows for the first time the regulatory effect of ATP and NADPH as physiological inhibitors of glycolysis and PPP in porcine COCs, respectively. Besides, these pathways seem to reach their maximum activities in porcine COCs during IVM because no further increases were achieved by the presence of AMP or NADP.     

Biomechanical Analysis of Torsion and Shear Forces in Lumbar and Lumbosacral Spine Segments of Nonchondrodystrophic Dogs

Objective— To determine stiffness and load–displacement curves as a biomechanical response to applied torsion and shear forces in cadaveric canine lumbar and lumbosacral specimens.
Study Design— Biomechanical study.
Animals— Caudal lumbar and lumbosacral functional spine units (FSU) of nonchondrodystrophic large-breed dogs (n=31) with radiographically normal spines.
Methods— FSU from dogs without musculoskeletal disease were tested in torsion in a custom-built spine loading simulator with 6 degrees of freedom, which uses orthogonally mounted electric motors to apply pure axial rotation. For shear tests, specimens were mounted to a custom-made shear-testing device, driven by a servo hydraulic testing machine. Load–displacement curves were recorded for torsion and shear.
Results— Left and right torsion stiffness was not different within each FSU level; however, torsional stiffness of L7-S1 was significantly smaller compared with lumbar FSU (L4-5–L6-7).
Ventral/dorsal stiffness was significantly different from lateral stiffness within an individual FSU level for L5-6, L6-7, and L7-S1 but not for L4-5. When the data from 4 tested shear directions from the same specimen were pooled, level L5-6 was significantly stiffer than L7-S1.
Conclusions— Increased range of motion of the lumbosacral joint is reflected by an overall decreased shear and rotational stiffness at the lumbosacral FSU.
Clinical Relevance— Data from dogs with disc degeneration have to be collected, analyzed, and compared with results from our chondrodystrophic large-breed dogs with radiographically normal spines.     

Wounds of the pastern and foot region managed with phalangeal casts: 50 cases in 49 horses (1995–2006)

Objective   Describe the use of a phalangeal cast as treatment for wounds in the pastern and foot region of horses. Secondly, to evaluate the healing and soundness of horses treated with phalangeal casts.
Design   Retrospective study of 49 horses.
Procedures   Medical records of 49 horses that were treated with a phalangeal cast for 50 cases of wounds in the pastern and foot region at equine referral hospitals from 1995 to 2006 were reviewed and follow-up information was obtained.
Results   Treatment consisted of wound debridement, lavage, wound closure (28 wounds), cast application and antibiotics (84%). At follow-up, the majority of horses were sound (42 of 47 wounds, 89.4%), three horses were still lame and one horse was euthanased because of persistent lameness. Three horses were lost to follow-up. There was no statistical difference between the outcomes of horses treated acutely (<24 h) or after a 24-h delay. Similarly, the involvement of synovial structures in the wound did not significantly influence outcome.
Conclusions   In this study, wounds involving the pastern and foot that were treated with a phalangeal cast carried a good prognosis for soundness (89.4%) and cosmetic healing (89.5%). The phalangeal casts were well-tolerated and effective.