Retrospective study of 108 foals with septic osteomyelitis

Objective   To determine the clinical characteristics, short-term outcome and future athletic performance of foals with septic osteomyelitis.
Design   Retrospective clinical study of 108 Thoroughbred foals with radiographic evidence of bone infection that were presented at the Scone Veterinary Hospital between August 1995 and December 2001. Medical records were reviewed and information concerning signalment, the clinical, laboratory and radiographic findings, treatment and outcome was obtained. Racing records were obtained and evaluated for surviving foals that had reached racing age.
Results   Mean age of foals at initial evaluation was 39 days (range 1–180 days); 21 foals had multiple radiographic bone lesions (19.4%), and 76 had concurrent septic arthritis (70.4%). The most frequently affected bones were the femur, tibia and distal phalanx. In total, 87 foals were discharged from the hospital (80.6%), 79 survived long-term to reach racing age and 52 raced (65.8%). Overall, 48% (52/108) of the foals treated for osteomyelitis raced. Foals less than 30 days of age at the time of diagnosis, critically ill foals and those with multiple bones or joints affected were significantly less likely to be discharged from hospital. Multiple septic joints, but not multiple bone involvement, had an unfavourable prognosis for racing.
Conclusions   The prognosis for survival of foals with septic osteomyelitis or osteitis is favourable. Multiple bone or joint involvement is an important short-term prognostic indicator; however, the involvement of multiple joints, but not multiple infected bones, is associated with an unfavourable prognosis for racing.     

Hemodynamic effects of intravenous lidocaine in isoflurane anesthetized cats

Lidocaine dose‐dependently decreases the minimum alveolar concentration (MAC) of isoflurane in cats. The purpose of this study was to determine the hemodynamic effects of six lidocaine plasma concentrations in isoflurane anesthetized cats. Six cats were studied. After instrumentation, end‐tidal isoflurane concentration was set at 1.25 times the individual minimum alveolar concentration (MAC), which was determined in a previous study. Lidocaine was administered intravenously to target pseudo‐steady state plasma concentrations of 0, 3, 5, 7, 9, and 11 μg ml^–1, and isoflurane concentration was reduced to an equipotent concentration, determined in a previous study. Cardiovascular variables; blood gases; PCV; total protein and lactate concentrations; and lidocaine and monoethylglycinexylidide concentrations were measured at each lidocaine target concentration, before and during noxious stimulation. Derived variables were calculated. Data were analyzed using a repeated measures anova , followed by a Tukey test for pairwise comparisons where appropriate. One cat was excluded from analysis because the study was aborted at 7 μg ml^–1 due to severe cardiorespiratory depression. Heart rate, cardiac index, stroke index, right ventricular stroke work index, total protein concentration, mixed‐venous PO₂ and hemoglobin oxygen saturation, arterial and mixed‐venous bicarbonate concentrations, and oxygen delivery were significantly lower during lidocaine administration than when no lidocaine was administered. Mean arterial pressure, central venous pressure, pulmonary artery pressure, systemic and pulmonary vascular resistance indices, PCV, arterial and mixed‐venous hemoglobin concentrations, lactate concentration, arterial oxygen concentration, and oxygen extraction ratio were significantly higher during administration of lidocaine than when no lidocaine was administered. Most changes were significant at lidocaine target plasma concentrations of 7 μg ml^–1 and above. Noxious stimulation did not significantly affect most variables. Despite significantly decreasing in inhalant requirements, when combined with isoflurane, lidocaine produces greater cardiovascular depression than an equipotent dose of isoflurane alone. The use of lidocaine to reduce isoflurane requirements is not recommended in cats.     

VCARS – veterinary computerized anesthetic record system

VCARS, the Veterinary Computerized Anesthetic Record System, has been developed to capture pre-, peri- and post-anesthetic data using Tablet PCs, 802.11b wireless networks, and a web-based database. Patient demographics, anticipated procedures and anesthetist, service information and hematologic and chemistry values are imported from the Veterinary Medical Teaching Hospital patient information system. Using a wireless Tablet PC, pre-anesthetic examination findings are recorded and an anesthetic plan including anesthetic drugs and anesthetic and monitoring equipment is developed. During induction and maintenance of anesthesia, physiologic variables, drug, fluid, anesthetic gas and oxygen administration, laboratory values, patient location, and important events can be charted with the simplicity of a paper anesthetic record. This information can be manipulated for display in a variety of ways depending on the specific needs of the case. Tools for calculating optimal fluid rates and drug dosages are incorporated into the design. The anesthetic records from multiple cases can be viewed simultaneously using a centrally-located monitor. Detailed audit trails ensure data integrity. A high-end search engine will allow rapid and complete retrieval of patient and anesthetic information. Macromedia flash is used to allow temporary disconnection from the wireless network without losing the ability to view, add, or edit data. The initial stages of software development are nearing completion, a wireless network is in place and hardware is being purchased. A pilot study will be conducted using manual entry of physiologic data prior to integration of automatically captured patient physiological variables. It is anticipated that this system will drastically improve the accuracy of data collection and retrieval and will provide important information about anesthetic management allowing improvement in overall patient care.     

Comparison of the efficacy of macrocyclic lactone anthelmintics,either singly or in combination with other anthelmintic(s), in nine beef herds in southern NSW

Anthelmintic resistance (AR) is a well-recognized challenge in farmed ruminants. The use of anthelmintics in combination is one of the strategies recommended to slow the rate of AR development. Two studies were undertaken in 2017 and 2019 to assess the efficacy of single-dose macrocyclic lactone (ML) anthelmintic and ML combination drenches. In total, 11 Faecal Egg Count Reduction Trials (FECRTs) were set up in 10 different beef herds, with results available from 10 of those FECRTs (9 herds). AR to a single ML anthelmintic was detected in all 9 herds, with resistance to Cooperia and Haemonchus spp on 9 farms, and resistance to Ostertagia and Trichostrongylus spp on 2 farms. In contrast, for the ML combination anthelmintics, all FECRTs resulted in efficacies of 99%–100%. The results suggest that cattle producers should strongly consider using combination drenches in their herds in preference to single actives.     

The diagnosis and treatment of a thoracic abscess in an alpaca

A 6-month-old alpaca presented for lethargy, failure to thrive and leucocytosis. Diagnostic procedures, including thoracic ultrasound, radiographs and a computed tomography scan, were used to document a thoracic mass. Based on appearance and ultrasound-guided aspiration of purulent material, the mass was determined to be a large abscess. The abscess was treated with surgical drainage and long-term antibiotic therapy. The origin of this thoracic abscess was felt to be the caudal mediastinum, secondary to bacterial seeding of the caudal mediastinal lymph nodes. Although an aetiological agent was not definitively determined, the most likely was Actinomyces spp or Arcanobacterium pyogenes. The alpaca made a complete recovery following treatment.     

OC1Effects of Cryopreservation on the Expression of Glut‐3, Glut‐5 and As‐A Proteins in Iberian Boar Sperm Membranes

In order to determine the injure produced in boar spermatozoa through cryopreservation process, we analyzed the expression of the hexose transporters Glut‐3 and Glut‐5 and the zona pellucida binding protein As‐A (P68) in three different steps of the freezing‐thawed protocol: at 17°C (fresh BTS‐diluted semen, 1 : 2 v/v, step 1), at 5°C (after glycerol addition; step 2), and post‐thawing (step 3). All sperm analyses were carried out with immunogold techniques under electronic microscopy. For this study eight healthy post‐pubertal Iberian boars were submitted to a collection of twice per week through 3 months, evaluating two ejaculates from each boar. Glut‐3 maintains the expression in the acrosome region post‐thawing but not along the tail where is reduced. The expression of Glut‐5 and As‐A is majority located at the post‐acrosome region of the spermatozoa at step 1, but in step 2 and step 3 this expression is relocated to sperm tail area. In conclusion, while cryopreservation affects the localization and the expression of Glut‐3 and Glut‐5, its fertilizing capacity is not significantly reduced. The stabilization of boar semen at 5°C was found to be the most crucial step for sperm survival.     

Neuronal Responses in the Brainstem and Hypothalamic Nuclei Following Insulin Treatment During the Late Follicular Phase in the Ewe

The aim of this study was to determine the neuronal responses following insulin administration during the late follicular phase. Intact ewes were given either saline or insulin (5 IU/kg, i.v.) at 35 h after progesterone withdrawal and killed 3 h later. There was a marked increase in the number of Fos‐positive noradrenergic neurones in the caudal brainstem of insulin‐treated ewes. In the hypothalamic paraventricular nucleus, insulin treatment increased the presence of Fos‐positive corticotrophin‐releasing hormone neurones (from 2% to 98%) and Fos‐positive arginine vasopressin parvocellular neurones (from 2% to 46%). Interestingly, after insulin treatment, despite a general increase in Fos‐positive neurones in the arcuate nucleus (ARC), there was a marked reduction (from 47% to 1%) in Fos‐positive β‐endorphin neurones. Similarly, colocalized Fos and oestradiol receptor (ER) α‐positive neurones decreased in the ARC after insulin (from 7% to 3%). Conversely, in the ventromedial nucleus, ERα‐positive neurones with Fos increased (from 7% to 22%) alongside a general increase in Fos‐positive neurones. Overall, a complex system of neurones in brainstem and hypothalamus is activated following insulin administration during the late follicular phase.     

Inhalant anesthetic requirement in cats is animal-dependent

Minimum alveolar concentration (MAC) of an inhalant is an indicator of its anesthetic potency. Individuals vary in their sensitivity to anesthetic agents as demonstrated by different individual MAC values. We hypothesized that individual animal sensitivity would be maintained with different inhalant anesthetics. As part of separate studies, six female DSH cats, aged 24 ± 2.5 (mean ± SD) months and weighing 3.5 ± 0.3 kg, were studied similarly on three separate occasions over a 12‐month period to determine the MAC of isoflurane (ISO), sevoflurane (SEVO), and desflurane (DES), respectively. In each study, chamber induction was followed by orotracheal intubation, and anesthesia was maintained via a nonrebreathing circuit. ECG, pulse oximetry, Doppler systolic blood pressure, end‐tidal gases, and esophageal temperature were monitored. End‐tidal gases were hand‐sampled from a catheter whose tip lay level with the distal end of the ET tube. Gases were analyzed by Raman spectrometry and, for each agent, the analyzer was calibrated with at least three gas standards. MAC was determined in triplicate using standard tail‐clamp technique. Data were analyzed by two‐way anova followed by Tukey's test and significant differences were found. Average MACs (%) for ISO, SEVO, and DES were 1.90 ± 0.18, 3.41 ± 0.65, and 10.27 ± 1.06, respectively. Body temperatures, Doppler systolic blood pressure, and SpO₂ were recorded at the time of MAC determinations for ISO, SEVO, and DES were 38.3 ± 0.3, 38.6 ± 0.1, 38.3 ± 0.35 °C; 71 ± 8, 75 ± 16, 88 ± 12 mm Hg; 99 ± 1, 99 ± 1, 99 ± 1%, respectively. Both the anesthetic agent and the individual cat had significant effects on MAC (p = 0.0001 and 0.0185, respectively). MAC varied between individuals and cats were consistent in their order of sensitivity to inhalant anesthetics across the three agents. Within this group of cats, the relationship of individual MAC to the group MAC for each of the three inhalant agents was maintained. This suggests that any individual may be consistently more or less sensitive to a variety of inhalant agents.