An outbreak of botulism in wild waterfowl in New Zealand

Extract

When an immune serum is fractionated into its major components, for example by electrophoresis, the bulk of its antibody activity is seen to occur in the gamma globulins with some slight additional activity in the beta globulins. Proteins that have antibody activity are called immunoglobulins; these are divided into classes which differ in their structure and biology. Five such classes, designated IgG, IgM, IgA, IgD, and IgE, have been described in man. Immunoglobulins analogous to those of man probably occur in all mammals but in most species they remain to be specifically identified. Furthermore, the features of a given immunoglobulin class are broadly the same regardless of the species in which it occurs.     

Enhanced IL-6 transcriptional response to adenosine receptor ligands in horses with lower airway inflammation

Reasons for performing study: Accumulation of extracellular adenosine has been closely associated with human asthmatic responses. However, the relevance of adenosine signalling in equine airways has not previously been investigated. Objectives: To determine the expression of adenosine receptors (AR) in bronchoalveolar lavage (BAL) cells and assess the reactivity of these cells to AR ligands ex vivo, employing IL‐6 as readout of adenosinergic inflammatory signalling. Methods: Eight horses with varying degrees of lower airway inflammation and 10 healthy controls were analysed. Expression of AR‐subtypes in each BAL sample was determined by quantitative RT‐PCR and compared to that in 13 other tissues. Bronchoalveolar lavage cells were stimulated either with the adenosine analogue NECA, CGS‐21680 (A_2AAR selective agonist) or with a combination of NECA and SCH‐58261 (A_2AAR antagonist) and IL‐6 expression assessed. Results: Bronchoalveolar lavage cells predominantly expressed A_2BAR, with lower A_2AAR levels and marginal A₃AR expression; A₁AR was not detected. This pattern was similar to that of PBMCs but different from the other tissues tested. No significant differences in AR expression in BAL cells from both groups were detected, although a trend for decreased A_2BAR in airway‐compromised horses was observed. Treatment of BAL cells with the nonselective agonist NECA upregulated IL‐6 expression in cells from airway‐compromised horses, but levels remained unchanged in control animals. Furthermore, blockage of A_2AAR with SCH‐58261 enhanced IL‐6 mRNA induction by NECA in both groups, with higher levels in airway‐compromised horses; the amplitude of this response correlated with neutrophil count. Conclusions: These results demonstrate the presence of an adenosine/IL‐6 inflammatory axis in the bronchoalveolar milieu of airway‐compromised horses. While A_2BAR is the predominant proinflammatory AR subtype expressed, A_2AAR appears to modulate inflammatory signalling (IL‐6 expression) by adenosine. Potential relevance: This study supports selective AR targeting as a potential therapeutic approach for the modulation of inflammation in the equine lower respiratory tract.     

Mandibular Osteodistraction for Correction of Deep Bite Class II Malocclusion in a Horse

Objective— To describe a technique for, and outcome after, mandibular osteodistraction in the horse.
Study Design— Clinical report.
Animals— Warmblood horse.
Methods— A half ring external fixator was applied on both sides of an osteotomy site performed on the mandible of a colt. A bite plate was placed on the upper incisors creating occlusion between lower and upper jaw. After a 5-day latency period, distraction was applied (1 mm/day) until the overjet was judged normal.
Results— Mandibular elongation and correction of brachygnathia was obtained without major complications. Six months after the procedure the overjet reduction was considered stable.
Conclusions— Mandibular osteodistraction can be considered for treatment of severe brachygnathia in yearlings.
Clinical Relevance— Distraction osteogenesis has the advantage of progressive elongation of the mandible, allowing concurrent bone remodeling and soft tissue adaptation. Severe mandibular incisor malocclusion in horses outside the maximal growth phase can be corrected using this technique.     

Practicality, Usefulness, and Limits of Pulse Oximetry in Critical Small Animal Patients

Pulse oximetry holds the promise of wide application for monitoring and assessing pulmonary function in small animal patients. Although the saturation as read by pulse oximetry (SpO2) has previously been shown to be accurate in healthy dogs, its accuracy and usefulness have not been demonstrated in critical small animal patients. The present study assessed the accuracy and usefulness of a pulse oximeter (Ohmeda Biox 3740, Ohmeda, Louisville, CO) in a small animal intensive care unit. The instrument yielded readings in 48 of 51 attempts in 33 animals (25 dogs, 8 cats). Criteria were developed to reject spurious readings; when these criteria were applied, the actual calculated SaO2 differed from the SpO2 by O.26 +2.2%, with a correlation of 0.87 (p<0.0001). The 95% confidence interval was +4.4%, comparable to the accepted level in humans. No ill effects from SpO2 were apparent in the patients, and the instrument was useful in monitoring the progress of critical animals. However, uncritical use of the oximeter could have led to gross patient mismanagement, as SpO2 readings as much as 29% different from SaO2 were sometimes obtained.