Scorer and modality agreement for the detection of intervertebral disc calcification in Dachshunds

Background: The Dachshund is a chondrodystrophic breed of dog predisposed to premature degeneration and calcification, and subsequent herniation, of intervertebral discs (IVDs). This condition is heritable in Dachshunds and breeding candidates are screened for radiographically detectable intervertebral disc calcification (RDIDC), a feature of advanced disc degeneration and a prognostic factor for clinical disease. RDIDC scoring has been previously shown to be consistent within scorers; however, strong scorer effect (subjectivity) was also reported. The aim of this study was to estimate the within- and between-scorer agreement (repeatability and reproducibility, respectively) of computed tomography (CT) scanning and magnetic resonance imaging (MRI) for scoring IVD calcification, and to compare these modalities with radiographic scoring. Results: Twenty-one Dachshund dogs were screened for IVD calcification using the three imaging modalities. Three scorers scored each case twice, independently. Repeatability was highest for radiography (95.4%), and significantly higher than for CT (90.4%) but not MRI (93.8%). Reproducibility was also highest for radiography (92.9%), but not significantly higher than for CT or MRI (89.4% and 86.4%, respectively). Overall, CT scored IVDs differently than radiography and MRI (64.8% and 62.7% agreement, respectively), while radiography and MRI scored more similarly (85.7% agreement). Conclusions: Despite high precision for radiography, previous evidence of scorer subjectivity was confirmed, which was not generally observed with CT and MRI. The increased consistency of radiography may be related to prior scorer experience with the modality and RDIDC scoring. This study does not support replacing radiography with CT or MRI to screen for heritable IVD calcification in breeding Dachshunds; however, evaluation of dog-level precision and the accuracy of each modality is recommended.Alana Jayne Rosenblatt, Anu Katriina Lappalainen, Nina Alice James, Natalie Siu Ling Webster, and Charles Grégoire Bénédict Carague

Chlamydia pecorum prevalence in South Australian koala (Phascolarctos cinereus) populations: identification and modelling of a population free from infection

Chlamydia pecorum is an established and prevalent infection that produces severe clinical disease in many koala populations, contributing to dramatic population declines. In wild South Australian koala populations, C. pecorum occurrence and distribution is unknown. Here, C. pecorum-specific real-time quantitative PCR (qPCR) was applied to ocular and urogenital swabs from targeted surveys of wild koalas from the mainland Mount Lofty Ranges (MLR) (n = 75) and Kangaroo Island (KI) (n = 170) populations. Historical data from 13,081 KI koalas (1997-2018) provided additional evidence for assessing the absence of C. pecorum infection. In the MLR population, 46.7% (CI: 35.1-58.6%) of koalas were C. pecorum positive by qPCR but only 4% had grade 3 clinical disease. MLR koala fertility was significantly reduced by C. pecorum infection; all reproductively active females (n = 16) were C. pecorum negative, whereas 85.2% of inactive females (n = 23) were positive (P < 0.001). KI koalas were C. pecorum negative and the population was demonstrated to be free of C. pecorum infection with 95% confidence. C. pecorum is a real threat for the sustainability of the koala and KI is possibly the last isolated, large C. pecorum-free population remaining in Australia. These koalas could provide a safeguard against this serious disease threat to an iconic Australian species.Jessica Fabijan, Charles Caraguel, Martina Jelocnik, Adam Polkinghorne, Wayne S.J. Boardman, Elisa Nishimoto, Greg Johnsson, Robyn Molsher, Lucy Woolford, Peter Timms, Greg Simmons, Farhid Hemmatzadeh, Darren J. Trott, Natasha Speigh

The two-step Fagan's nomogram: ad hoc interpretation of a diagnostic test result without calculation

In 1975, Fagan published a nomogram to help practitioners determine, without the use of a calculator or computer, the probability of a patient truly having a condition of interest given a particular test result. Nomograms are very useful for bedside interpretations of test results, as no test is perfect. However, the practicality of Fagan's nomogram is limited by its use of the likelihood ratio (LR), a parameter not commonly reported in the evaluation studies of diagnostic tests. The LR reflects the direction and strength of evidence provided by a test result and can be computed from the conventional diagnostic sensitivity (DSe) and specificity (DSp) of the test. This initial computation is absent in Fagan's nomogram, making it impractical for routine use. We have seamlessly integrated the initial step to compute the LR and the resulting two-step nomogram allows the user to quickly interpret the outcome of a test. With the addition of the DSe and DSp, the nomogram, for the purposes of interpreting a dichotomous test result, is now complete. This tool is more accessible and flexible than the original, which will facilitate its use in routine evidence-based practice. The nomogram can be downloaded at: www.adelaide.edu.au/vetsci/research/pub_pop/2step-nomogram/.Charles G B Caraguel, Raphaël Vanderstiche

The Canadian harp seal hunt: observations on the effectiveness of procedures to avoid poor animal welfare outcomes

The Canadian harp seal (Pagophilus groenlandicus) hunt has, for several decades, raised public concerns related to animal welfare. The field conditions under which this hunt is carried out do not lend themselves easily to detailed observations and analyses of its killing practices. This article reports observations carried out over several seasons that aimed at obtaining more specific information about the conditions under which seals are killed, in order to assess potential welfare issues and explore avenues for possible improvements in its practice. A standardised three-step process for killing seals (ie stunning, checking by palpation of the skull, and bleeding) was recently implemented to maximise the proportion of animals that are killed rapidly with minimum pain. Based on field observations, the rifle and the hakapik, when used properly, appeared to be efficient tools for stunning and/or killing young harp seals. All carcases of seals observed to be killed with a rifle, either on the ice or in the water, could be recovered. However, shooting seals in water rather than on ice carried a higher risk of poor welfare outcome because of the limited opportunities to shoot the animals again if not stunned with the first shot. Based on current practices, there is no reliable evidence that the Canadian harp seal hunt differs from other forms of exploitation of wildlife resources from the perspective of animal welfare. Although opportunistic field observations may be less amenable to generalisation than structured studies, we believe that they reflect the reality of the hunt and provide valuable information to direct the evolution of its practice.P.-Y. Daoust and C. Carague

Mandatory desexing of dogs: one step in the right direction to reduce the risk of dog bite? A systematic review

Published Online First 27 January 2017INTRODUCTION: Preventing dog bites is an intractable problem given the complex dog bite injury environment. Desexing of dogs has the opportunity of creating a safer injury environment, given the potential links between desexing and behaviour change in dogs. METHODS: A systematic review of the literature was conducted to examine the evidence for desexing of dogs to reduce dog bite risk within a population health paradigm. Medline and CAB Abstracts were searched for studies that reported data on the association of dog neuter status with the risk of dog bite. All definitions of dog bite were included and all empirical studies were included in the review, limited to those published in English. Quality appraisal and data extraction were based on the 2013 evidence-based practice and critical appraisal tool from the University of Auckland. RESULTS: Five out of six observational studies, from four study populations found evidence that intact dogs were associated with an increased risk of dog bite compared with desexed dogs. The effect sizes ranged across the studies and given the heterogeneity of the studies no single effect size on the association between desexing and dog bite risk could be estimated. CONCLUSIONS: There is consistent evidence that desexing dogs is associated with a reduced risk of dog bite, although the studies reflect association and may not be causal. Although recent publications have suggested desexing is associated with health and behavioural costs in some breeds, population level evidence supports desexed dogs having a longer lifespan, and being less likely to wander with the added benefit of reducing unwanted litters. Thus, mandatory desexing presents a possible opportunity for prevention of dog bites expanding dog bite prevention beyond an education-only approach.Katina D'Onise, Susan Hazel, Charles Carague

Selection and interpretation of diagnostic tests in aquaculture biosecurity

In biosecurity-related activities in aquaculture, diagnostic tests are commonly used to (1) demonstrate freedom from infection in a facility, (2) screen aquatic animals prior to introduction to the receiving facility, (3) detect infected animals as early as possible during a quarantine period, and (4) confirm suspicious or clinical case(s). The interpretation of test result(s) is indicative of the true infection status at the individual and at the group levels and has direct implications in completing the stepwise process for Effective Veterinary Biosecurity as proposed by the International Aquatic Veterinary Biosecurity Consortium. The confidence regarding a test result depends on the anticipated level of infection in the investigated aquatic animal population and on the diagnostic sensitivity and specificity of the tests. Depending on the testing intended purpose, the test of choice or combination of test may vary and is primarily based on the test diagnostic sensitivity or specificity. Additional strategies for maximizing the chance of a test result to be true are described in the context of each testing activity and targeted unit of interest (i.e., individual fish or group of fish).Charles G. B. Caraguel, Ian A. Gardner and Larry K. Hammel

Comparison of the thickness of the calvarium between young grey (Halichoerus grypus) and harp (Pagophilus groenlandicus) seals

Title and Abstract in English and French. French title: Comparaison de l'épaisseur de la calotte crânienne entre les jeunes phoques gris (Halichoerus grypus) et les jeunes phoques du Groenland (Pagophilus groenlandicus).Young harp seals (Pagophilus groenlandicus) have traditionally been hunted along the Canadian Atlantic coast, and regulations are now in place to ensure that this hunt meets adequate standards of animal welfare. These young seals are killed by a blow to the head from a hakapik or a club or by a bullet to the head. A hunt for young grey seals (Halichoerus grypus), using similar methods, occurs intermittently on a smaller scale around the Canadian Maritime provinces. However, field observations suggest that the skull of young grey seals is substantially thicker than that of young harp seals. The results of this study confirm these field observations and suggest the need for further research when adapting the current hunting methods for young harp seals to grey seals. = Les jeunes phoques du Groenland (Pagophilus groenlandicus) ont historiquement été chassés sur la côte atlantique du Canada, et des règlements sont maintenant en place pour assurer que cette chasse se déroule selon des standards de bien-être animal adéquats. Ces jeunes phoques sont tués par un coup de hakapik ou de gourdin sur la tête ou par une balle de carabine dans la tête. Une chasse à plus petite échelle pour les jeunes phoques gris (Halichoerus grypus), utilisant des méthodes similaires, se fait de manière intermittente dans les provinces maritimes. Cependant, les observations sur le terrain suggèrent que le crâne des jeunes phoques gris est nettement plus épais que celui des phoques du Groenland. Les résultats de cette étude confirment ces observations et suggèrent un besoin de recherche pour adapter les méthodes de chasse courantes pour les jeunes phoques du Groenland aux jeunes phoques gris.Charles Caraguel, Pierre-Yves Daoust, and Fiep de Bi

Real-time monitoring of the core body temperature in endurance horses during field exercise

Abstract onlyVerdegaal E, Jonas S, Caraguel C, Franklin

Chasing Salmonella Typhimurium in free range egg production system

Abstract not availableKapil Chousalkar, Vaibhav Gole, Charles Caraguel, Jean-Loup Raul