Veterinary Clinical Sciences - Research Publications
Now showing items 1-12 of 158
Fibrinogen heterogeneity in horses
BACKGROUND: Fibrinogen heterogeneity has been observed in humans and can influence fibrinogen measurements when using the modified Clauss assay. We hypothesized that fibrinogen heterogeneity also exists in horses. OBJECTIVES: To determine whether fibrinogen heterogeneity exists in horses. ANIMALS: Five clinically healthy horses from the university equine teaching herd. METHODS: Presumed fibrinogen was purified from pooled citrated plasma and electrophoresis performed. The purified protein was subjected to Western blotting using sheep antiserum against human fibrinogen, and liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: Gel electrophoresis of nonreduced equine purified protein yielded 2 protein bands (approximately 377 and 318 kDa) that corresponded with the molecular weights of human high molecular weight fibrinogen and low molecular weight fibrinogen fractions, respectively. Electrophoretograms of reduced purified protein, Western blots, and LC-MS/MS supported that the purified nonreduced protein bands were fibrinogen. CONCLUSION: Fibrinogen heterogeneity exists in horses.
A comparison of fragmenting lead-based and lead-free bullets for aerial shooting of wild pigs
(PUBLIC LIBRARY SCIENCE, 2021-03-11)
In response to the health threats posed by toxic lead to humans, scavenging wildlife and the environment, there is currently a focus on transitioning from lead-based to lead-free bullets for shooting of wild animals. We compared efficiency metrics and terminal ballistic performance for lead-based and lead-free (non-lead) bullets for aerial shooting of wild pigs (Sus scrofa) in eastern Australia. Ballistic testing revealed that lead-based and lead-free bullets achieved similar performance in precision and muzzle kinetic energy (E0) levels (3337.2 J and 3345.7 J, respectively). An aerial shooting trial was conducted with wild pigs shot with one type of lead-based and one type of lead-free bullets under identical conditions. Observations were made from 859 shooting events (n = 430 and 429 respectively), with a sub-set of pigs examined via gross post-mortem (n = 100 and 108 respectively), and a further sub-set examined via radiography (n = 94 and 101 respectively). The mean number of bullets fired per pig killed did not differ greatly between lead-based and lead-free bullets respectively (4.09 vs 3.91), nor did the mean number of bullet wound tracts in each animal via post-mortem inspection (3.29 vs 2.98). However, radiography revealed a higher average number of fragments per animal (median >300 vs median = 55) and a broader distribution of fragments with lead-based bullets. Our results suggest that lead-based and lead-free bullets are similarly effective for aerial shooting of wild pigs, but that the bullet types behave differently, with lead-based bullets displaying a higher degree of fragmentation. These results suggest that aerial shooting may be a particularly important contributor to scavenging wildlife being exposed to lead and that investigation of lead-free bullets for this use should continue.
Visitor Attitudes Toward Little Penguins (Eudyptula minor) at Two Australian Zoos
(FRONTIERS MEDIA SA, 2021-02-11)
This study identified and compared the attitudes of visitors toward zoo-housed little penguins, their enclosure and visitor experience that may influence the way visitors behave toward little penguins at two Australian zoos. Visitor attitudes were assessed using an anonymous questionnaire, targeting visitor beliefs, and experiences, where visitors were randomly approached at the penguin exhibit after they had finished viewing the penguins. Visitors were given two options to complete the questionnaire, on an iPad during their zoo visit or online (URL sent via email) after their zoo visit. A total of 638 participants (495 at Melbourne Zoo and 143 at Taronga Zoo) completed the questionnaire, 42% were completed onsite during their zoo visit and 58% were completed online after their zoo visit. Most participants were living in Australia, non-zoo members, female, previously or currently owned a pet, aged between 26 and 35 years and had a University degree. Results showed that the attitude dimensions of visitors were consistent between the two zoos which indicates that these measures of attitudes were stable over time and location. Overall, visitors at both zoos had positive attitudes toward little penguins, penguin welfare, the enclosure, and visitor experience. However, whether these positive attitudes and positive visitor experience influenced the way visitors behaved toward the penguins remains unclear. There were some differences in visitor attitudes toward the perceived "aggressiveness" and "timidness" of little penguins, "negative penguin welfare", "experience with the penguins", "learning", "visual barriers" and the way visitors rated their overall experience at the penguin enclosure. While the reasons for the differences in visitor attitudes and visitor experience between the zoos were not clear, some factors such as penguin behavior and enclosure design, may have been attributable to these differences. Also, a relationship was found between visitor attitudes and how visitors rated the welfare of penguins, the enclosure and visitor experience at the enclosure; more positive visitor attitudes were associated with higher ratings of penguin welfare, the enclosure and visitor experience. The practical implications of these results for zoos is unclear because the differences in visitor attitudes were numerically small. This requires further comparisons between zoos or enclosures that are more markedly different than the penguin enclosures in the present study and further research on how visitors assess zoo animals, enclosures and visitor experience.
Effects of Positive Human Contact during Gestation on the Behaviour, Physiology and Reproductive Performance of Sows
Previous positive interactions with humans may ameliorate the stress response of farm animals to aversive routine practices such as painful or stressful procedures, particularly those associated with stockpeople. We studied the effects of positive handling by providing younger (parity 1-2) and older (parity 3-8) sows housed in pens of fifteen (n = 24 pens in total) with either positive human contact (+HC) or routine human contact (control) during gestation. The +HC treatment involved a familiar stockperson patting and scratching sows and was imposed at a pen-level for 2 min daily. Measurements studied included behavioural, physiological and productivity variables. The +HC sows showed reduced avoidance of the stockperson conducting pregnancy testing and vaccination in the home pens, however the behavioural and cortisol responses of sows in a standard unfamiliar human approach test did not differ. There were no effects of +HC on aggression between sows, serum cortisol or serum brain-derived neurotrophic factor concentrations during gestation, or on the behavioural and cortisol response to being moved to farrowing crates. There were also no effects of +HC on the maternal responsiveness of sows, farrowing rate or the number of piglets born alive, stillborn or weaned. Sows in the +HC pens reduced their physical interaction with the stockpeople imposing the treatment after 2 weeks, which suggests the sows may have habituated to the novel or possible rewarding elements of the handling treatment. This experiment shows that regular positive interaction with stockpeople does reduce sows' fear of stockpeople, but does not always confer stress resilence.
The Human-Horse Relationship: Identifying the Antecedents of Horse Owner Attitudes towards Horse Husbandry and Management Behaviour
The welfare of recreational horses is an important issue. Horse owner attitudes towards horse ownership are likely to influence owner behaviour in terms of horse husbandry and management practices and human-horse interactions, which in turn are likely to affect the welfare of the horse. Based on Ajzen's Theory of Planned Behaviour, this paper examines the relationships between horse owner attributes, specifically background factors (demographics, knowledge, and experience) and attitudes (beliefs) towards horse husbandry and management behaviour. Data were collected via a random telephone survey and during on-site inspections with Victorian horse owners and their horses (n = 57), using an attitude questionnaire. Relationships were found between horse owner background factors and horse owner attitudes towards horse husbandry and management behaviour. Generally, belief variables correlated significantly with background factors that were primarily related to knowledge and experience. Further, beliefs concerning three key husbandry practices (parasite control, hoof care, and dental care) all appear to be predicted to some degree by background factors associated with knowledge and experience. Therefore, a practical recommendation may be the implementation of education and training programs aimed at improving horse owner knowledge and experience regarding effective horse husbandry and management to promote horse welfare. Clearly, further research is warranted.
Social License and Animal Welfare: Developments from the Past Decade in Australia
"Social license to operate" (SLO) refers to the implicit process by which a community gives an industry approval to conduct its current business activities. It has become an important focus for many natural resource management fields (especially mining), but there is less awareness of its role in animal use industries. This article describes how animal welfare has recently become arguably the most crucial consideration underpinning the SLO for Australian animal use industries. It describes several industries in Australia that have faced animal welfare scrutiny in the past decade (2010-2020) to illustrate how persistent issues can erode SLO, lead to regulatory bans, and decimate previously profitable industries. Industries described include the live export of livestock, greyhound and horse racing, kangaroo harvesting, and dairy and sheep farming. In these cases, there has been intense public discourse but little scholarly progress. This article examines factors that may have contributed to these developments and suggests approaches that may assist these industries in maintaining their SLO. Animal welfare has become a mainstream societal concern in Australia, and effective management of the community's expectations will be essential for the maintenance of SLO for many animal use industries.
A Systematic Review of Heat Load in Australian Livestock Transported by Sea
The transport of animals by sea ('live export') is one of the most important current animal welfare issues in Australian society. Recent media attention has highlighted concerns regarding the effects of high environmental temperature and humidity on the welfare and mortality of sheep being shipped live from Australia to the Middle East, especially during the Northern Hemisphere summer. To improve understanding of how and why harmful heat load occurs, we systematically reviewed Australian research into heat load and sea transport. High thermal load occurs during the sea transport of sheep and cattle from Australia when animals are subject to hot and humid environmental conditions and cannot remove heat generated by metabolic processes in the body, potentially also gaining heat from the environment. Several approaches have been proposed to mitigate these risks, including avoidance of voyages in hot seasons, selection of heat-resistant livestock breeds, reducing stocking density, and improved ventilation. We identified a lack of scientific literature relating to heat load in animals transported by sea and considerable potential for bias in the literature that was found. We identified the following priority research areas: (i) experimental manipulation of variables thought to influence the incidence and severity of harmful heat load, including sheep density; (ii) further assessment of the Heat Stress Risk Assessment (HSRA) model used to predict heat load events, and (iii) development of a suite of animal welfare indicators that may allow identification of 'at risk' sheep before they reach debilitating heat load condition. Addressing these knowledge gaps will assist efforts to reduce the frequency and intensity of harmful heat load events.
Efficacy and Animal Welfare Impacts of Novel Capture Methods for Two Species of Invasive Wild Mammals in New Zealand
All capture methods impose animal welfare impacts, but these impacts are rarely quantified or reported. We present data from two wildlife capture studies that trialled new methods for capturing Bennett's wallabies (Notamacropus rufogriseus) and red deer (Cervus elaphus) in New Zealand. We used helicopter net-gunning for both species, and compared this method with ground-based netting for wallabies and helicopter darting for red deer, using, for the first time in New Zealand, the fast-acting opioid thiafentanil. Efficacy and animal welfare parameters quantified were duration of handling and recovery, and frequency of adverse events, including escape, injury, and mortality. Cost-effectiveness was quantified for each method. Capture mortalities occurred for all methods for both species. For red deer, chemical immobilisation led to fewer traumatic injuries and fewer mortalities, while for wallabies, net-gunning led to fewer mortalities. Net-gunning was an efficient capture method for deer in open habitat, but led to the escape of 54% of wallabies and one wallaby mortality (4%). Ground-based netting resulted in the mortality of 17% of wallabies at the time of capture, and the capture of non-target species. The cost per captured wallaby was 40% more expensive for net-gunning (NZ$1045) than for ground-based netting (NZ$745), but, once corrected for mortalities at the time of capture and suitability of individuals for GPS-collar deployment, this was reduced to 29% and 12% more expensive, respectively. Net-gunning for red deer resulted in the escape of 13% of animals and mortality of 10% of animals at the time of capture. Helicopter-based darting for red deer using thiafentanil (c. 0.03-0.06 mg/kg) had high capture efficacy (zero escapes), rapid induction times (mean of 3 min), and a low mortality rate at 14 days post-capture (3%), but it was more expensive per deer captured and collared than aerial netting (NZ$2677 and NZ$2234, respectively). We recommend reporting of adverse event data for all wildlife capture techniques to permit continual refinement of field methods.
Human Behaviour Change Interventions in Animal Care and Interactive Settings: A Review and Framework for Design and Evaluation
Behaviour change interventions may be one of the most promising avenues to improve animal welfare. Yet there has been limited systematic research involving them in animal-related settings. We searched three major databases for studies involving an intervention to change interactive or care-related behaviours in any animal-related setting. Forty-seven papers were included in the review and each paper was coded for specific design and evaluation elements. We found a series of limitations in the quality and consistency of intervention design, evaluation, and reporting. Hence, we present a framework, the "Ten-Task" guide, based on the intervention mapping framework, to guide future work in this field. Adopting this structured approach will improve the quality and efficacy of behaviour change interventions for animal welfare and allow for the field to progress in a harmonious way.
Nasal dermoid cyst with intracranial extension in a cat.
(SAGE Publications, 2019-01)
Case summary: An 11-month-old female neutered Ragdoll cat was presented for focal seizures, aggression and altered behaviour. A diagnosis of a nasal dermoid cyst with intracranial extension was made following MRI, cytology and histopathology. The cyst was surgically excised with a resolution of clinical signs, with the exception of ongoing seizure activity requiring anti-seizure medication. Relevance and novel information: To our knowledge, this is the first reported case of a nasal dermoid cyst in a cat, and the first reported case in the veterinary literature of any species with a nasal dermoid cyst presenting with neurological signs.
How many to sample? Statistical guidelines for monitoring animal welfare outcomes
(PUBLIC LIBRARY SCIENCE, 2019-01-30)
There is increasing scrutiny of the animal welfare impacts of all animal use activities, including agriculture, the keeping of companion animals, racing and entertainment, research and laboratory use, and wildlife management programs. A common objective of animal welfare monitoring is to quantify the frequency of adverse animal events (e.g., injuries or mortalities). The frequency of such events can be used to provide pass/fail grades for animal use activities relative to a defined threshold and to identify areas for improvement through research. A critical question in these situations is how many animals should be sampled? There are, however, few guidelines available for data collection or analysis, and consequently sample sizes can be highly variable. To address this question, we first evaluated the effect of sample size on precision and statistical power in reporting the frequency of adverse animal welfare outcomes. We next used these findings to assess the precision of published animal welfare investigations for a range of contentious animal use activities, including livestock transport, horse racing, and wildlife harvesting and capture. Finally, we evaluated the sample sizes required for comparing observed outcomes with specified standards through hypothesis testing. Our simulations revealed that the sample sizes required for reasonable levels of precision (i.e., proportional distance to the upper confidence interval limit (δ) of ≤ 0.50) are greater than those that have been commonly used for animal welfare assessments (i.e., >300). Larger sample sizes are required for adverse events with low frequency (i.e., <5%). For comparison with a required threshold standard, even larger samples sizes are required. We present guidelines, and an online calculator, for minimum sample sizes for use in future animal welfare assessments of animal management and research programs.
Corrective wedge ostectomy for an atypical femoral procurvatum deformity stabilised with a supracondylar bone plate.
Physeal fractures of the distal femur are among the most commonly encountered fractures in skeletally immature dogs. These fractures respond poorly to conservative management and thus early surgical reduction and stabilisation are recommended. A 7-month-old intact male Border collie presented with a history of chronic lameness. Clinical examination revealed a predominantly non-weight-bearing lameness of the right hindlimb and concurrent muscle atrophy. A pronounced, but atypical, procurvatum deformity of the right distal femur was diagnosed on survey radiographs. Malunion of a Salter-Harris Type III physeal fracture was suspected as there was an associated history of trauma. A cranially based closing wedge ostectomy was performed to address the femoral deformity and subsequently stabilised using a supracondylar bone plate. The dog recovered well and was moderately weight-bearing lame on the right hindlimb 6 weeks post-operatively. Ten months following the operation the range of motion had improved in the right stifle and no signs of lameness were evident at a walk. We advocate surgical correction of sagittal plane deformities of the distal femur using the CORA method. Overall, a good functional outcome was achieved, which is consistent with previously reported cases with similar deformities.