David Fraser


Relevant Degree Programs

Affiliations to Research Centres, Institutes & Clusters


Graduate Student Supervision

Doctoral Student Supervision (Jan 2008 - April 2022)
Facial expression, vocalizations and eye temperature as potential indicators of pain in harbour seals (Phoca vitulina) (2019)

Pain assessment in animals typically relies on a combination of physiological and behavioural measures. Unfortunately, many of these measures require handling the animals or physical sampling, which are invasive and can result in a stress response. The aim of this thesis was to identify some possible non-invasive indicators of pain in harbour seals as no clear species-specific indicators had been established. I investigated whether or not seals showed changes in facial expression and other behaviours (Chapter 2), vocalizations (Chapter 3), or eye temperature (Chapter 4) in response to the routine procedures of flipper-tagging and microchipping. Seals showed changes in facial expression and in several other behaviours in response to the procedures. Most notably, orbital tightening increased from before to after tagging and microchipping (p
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Management of vulnerable dairy cows (2019)

Dairy farmers, scientists and critics have raised concerns over the current management of non-ambulatory and cull dairy cows at the farm and after they enter the marketing system. Inadequate management of non-ambulatory cows is indicated by low recovery rate and insufficient nursing care provided to these animals. Similarly, the large number of compromised cull dairy cows observed at livestock markets and abattoirs indicates poor on-farm culling decisions and/or a prolonged marketing process that significantly reduces animal welfare. The goals of this thesis were to quantify factors that may increase recovery of non-ambulatory cows, to describe the diverse management of cull dairy cows in Canada particularly the movement of cull dairy cows in British Columbia, and to quantify changes in the cows’ condition when moved from the farm to an abattoir. In Chapter 1, I describe the culling process as part of herd management and underline the most common culling reasons and their effects on animal welfare. In Chapter 2 I quantified factors that could improve recovery of cows subjected to flotation therapy, and found that shorter recumbency duration and provision of good nursing care can improve recovery. To describe the diverse management of cull dairy cows in Canada I used input from a meeting that involved a diverse group of experts from different regions of the country; this also resulted in 9 recommendations to guide future research and policy (Chapter 3). In Chapter 4, I evaluated the condition of cull dairy cows sold at livestock markets and found that 30% of the cows were compromised, and that compromised cows were more often observed during months with increased milk demand, likely because of delayed culling. To evaluate changes in the condition of cull dairy cows while in the marketing system, I monitored cows from farm to slaughter. I found that most cows spent more than 3 days in the marketing system, and many lost body condition and developed an engorged or inflamed udder (Chapter 5). These findings improve our understanding how vulnerable cows are managed and will help to guide future research, policy and development of better industry practices.

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Understanding the welfare of rats living in standard versus semi-naturalistic laboratory environments (2016)

Rats are one of the most commonly used animals in research. Differences in rat housing lead to differences in brain, behaviour, physiology and health. These differences can also affect rat welfare and the validity of data obtained from these animals. Few studies have assessed the consequences of housing rats in standard laboratory cages compared to more complex, naturalistic environments; fewer still have assessed these consequences in females, or after more than a few weeks of differential housing. The aim of my thesis was to assess the sustained welfare consequences of housing female rats in standard versus semi-naturalistic laboratory conditions. The psychological well-being of animals is central to the concept of animal welfare, so Chapter 2 provides a review of the scientific methods of assessing affective states in animals, how these methods have been applied to rats, and what the results can tell us about rats’ experience of various emotional states. Chapter 3 investigated rats’ propensity to engage in behaviours that are not possible in standard laboratory cages: burrowing, climbing and standing upright. Results indicated that burrowing and standing upright may be especially important to rats. Chapter 4 assessed the sustained affective consequences of standard versus semi-naturalistic housing using an anticipatory behaviour test. Results indicated that standard-housed rats were experiencing poorer welfare than the semi-naturalistic-housed rats. These studies were not designed to test differences in health between the two housing conditions, but given the very limited amount of research on the long-term health effects of differential housing in rats, Chapter 5 documented differences in body weight and development of naturally-occurring tumours. Standard-housed rats were much heavier than semi-naturalistic-housed rats, but there were no differences in the rate of tumour development. Collectively, these results indicate that, compared to the semi-naturalistic housing assessed in this thesis, standard laboratory housing for rats compromises rat welfare by 1) preventing the performance of important natural behaviours; 2) leading to negative affective states; and 3) leading to overweight animals predisposed to developing other health issues. Implications for rat welfare and the quality of the science obtained from standard-housed rats are discussed, and recommendations are provided.

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Translocation stress in Stephens' kangaroo rats: How individual variation influences success (2014)

Wildlife translocation involves the relocation of free-ranging animals from one area to another. It is commonly used to combat species loss. However, its outcomes are poor; some reviews put the success rate as low as 10-25%. This is likely influenced by a lack of attention to individuals. Translocations involve some combination of stressors (e.g., capture, captivity, monitoring, environmental change). Although animals have evolved behavioural and physiological mechanisms to manage challenges, the combination of stressors during translocation can compromise these coping mechanisms. Personality should have significance for translocations as individuals with certain personality types and life experience may handle translocation stressors better than others. The aim of this thesis was to profile individual Stephens’ kangaroo rats (SKR), Dipodomys stephensi, and to assess their responses to translocation. To do this a combination of behavioural and physiological measures were used. Personality types were identified using quantitative and qualitative measures from mirror-image stimulation and predator scent tests done while animals were held before release (Chapters 3 and 5). A radioimmunoassay specific for cortisol in SKR fecal extract was developed and adrenocortical activity (cortisol) in response to predator urine was reliably assessed in fecal samples (Chapter 2). Fecal cortisol concentration (FCC) was used to measure the effect of translocation stressors, including the use of radio transmitters (Chapters 4 and 5). Survival was affected by individual variation in behavioural and physiological responses (Chapter 5). Assertiveness, Excitability and Persistence were identified as three personality dimensions. Overall, FCC increased in response to temporary captivity. Radio transmitters caused a short-term elevation in FCC 6 days after attachment but not at 30 days. Survival to 1 month was similar for animals with and without transmitters. SKR with lower Assertiveness and Excitability and with higher basal FCC had higher short-term survival. Higher Assertiveness was correlated with lower basal FCC. SKR that had a smaller change in FCC during captivity had higher long-term survival. This study lends convincing support that variation in personality affects how well an animal copes with translocation and has consequences for survival. Knowing how to manage different personality types may determine how successfully a translocated population establishes itself.

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Understanding humane expectations: Public and expert attitudes toward human-wildlife interactions (2014)

The field of wildlife management has been on a collision course with societal values regarding animal use for some time. Although wildlife populations are still managed largely under the “North American model of wildlife conservation” to accommodate consumptive uses, many people, often with different concerns, want to be heard in decisions about wildlife. These human dimensions present a challenge to wildlife management, a field in which policy has been generally driven by experts. This research used several public engagement methods to understand broader attitudes towards wildlife management and how to incorporate them into policy. Participants with varying levels of wildlife experience in British Columbia, Canada, were asked in online and telephone surveys for their attitudes towards, and acceptance of, specific wildlife activities and management practices. Findings indicate a gap between public and expert opinions on invasive (e.g., relocation) and lethal management practices (e.g., problem bears, predator control, protection of endangered species). Problems also emerged with the public view of wildlife feeding. This led to a review of its motivations, types and consequences, and an evaluative framework was proposed to assess when feeding is acceptable. When asked to rate the harm to wildlife caused in various ways (hunting, vehicle collisions, pollution, etc.), experts and the public largely agreed on the relative importance of harms, indicating considerable potential for finding common ground between conservation-oriented and welfare-oriented citizens. However, some current management practices, especially those involving killing animals, lacked broad public support and may be improved upon with public participation in policy development, especially with women, urban residents, those with low wildlife engagement and animal-protectionist values. This could take the form of public polling or increased representation on decision-making committees. Societal expectations for managing human-wildlife interactions in BC documented by this research include ensuring that actions have an appropriate conservation purpose, are controllable, use humane methods, and appear fair to both people and wildlife. Including a broader public, educating both experts and the public on issues of humaneness, and strengthening wildlife and animal protection laws and enforcement, may serve to better align wildlife policy with societal values.

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Canadian poducer and citizen perspectives on farm animal welfare: Identifying shared and differing values (2013)

While interest in the “proper” care of food animals dates to early Greece, 20th century cultural developments in the West brought about an explosion of policies and programs intended to ensure suitable care and handling practices for food animals. “Animal welfare”, however, is a complex term reflecting a wide range of elements. Hence, animal care policies often lead to confusion and disagreements. Given that animal welfare preferences tend to reflect fundamental values and attitudes, agreement on animal care practices are most apt to ensue if such practices reflect shared values and attitudes among vested stakeholders. In an effort to contribute to the development of broadly acceptable policies and practices, in-depth interviews were conducted with beef cattle producers (n=23), pig producers (n=20), and the public (n=24) in the quest for shared or overlapping values regarding farm animal welfare. Areas of agreement include: (i) the importance of humane handling plus good health and biological functioning, especially emphasized by producers; (ii) that consumers have considerable power to dictate preferred care practices and that producers are constrained by economic pressures in competitive markets; and (iii) that citizens lack sufficient understanding of contemporary production methods. Commensurate policy recommendations intended to build on areas of agreement include: (i) the promotion of shared terminology emphasizing animal care; (ii) incorporating elements of natural living into intensive production systems; (iii) promoting joint stakeholder pilot projects to test welfare-oriented production methods or prevent catastrophic animal care failures; (iv) facilitating a trustworthy system of product labelling; (v) encouraging transparent producer or industry driven, welfare-related initiatives; and (vi) encouraging stakeholders to use publicly trusted educational resources instead of marketing-oriented representations of animal care practices. Future research recommendations include: (i) more qualitative and empirical studies of consumers’ welfare-related purchasing practices; and (ii) exploring producer welfare concerns in the broader context of production or management priorities or values. Contributions to existing knowledge include the identification of shared and differing values among Canadian stakeholders, challenges to blanket welfare criticisms about commercial production, plausible paradigmatic differences between producers and citizens, and the potential impact of differing production systems on the welfare-related views of producers.

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Master's Student Supervision (2010 - 2021)
Non-target interactions and humane evaluation of a captive bolt trap on commensal rodents (2021)

The Goodnature® A24 automatic rat trap is a self-resetting captive-bolt trap powered by pressurized CO₂, designed with the objective of instantly rendering animals unconscious followed by death, but little research has examined the humaneness of the trap or its potential to harm non-target mammals and birds. This study aimed to identify potential risks to non-target animals, and to evaluate its humaneness in killing target rodents. Seventeen traps, each paired with a motion-activated video camera, were deployed at two sites where rodents were present. In a 9-week study designed to assess risks to non-target animals, traps were baited but not activated, and a blocking device (“blocker”) was used in a cross-over design to evaluate its potential at reducing non-target strikes. A total of 2,282 interactions involving 33 species were recorded, with mice and rats as the most common mammals (566 visits), followed by squirrels, raccoons, skunks, and shrews. Birds were often observed (1,312 visits), but had little interaction with the trap. Raccoons and squirrels were observed either entering the trap or inserting limbs in the trap 36 times when no blocker was in place, but these interactions did not occur for traps with a blocker. Once the researchers were confident in avoiding non-target strikes, the traps were activated and recorded for 19 weeks across two different locations to evaluate humaneness. Surprisingly, only 11 trap triggers and eight kills were observed across the two locations. Of the eight kills (3 house mice, 4 deer mice, 1 grey squirrel), observations indicated immediate or near-immediate cessation of movement and apparently instantaneous death. Post-mortem analysis by micro-CT supports observations of immediate unconsciousness. One Norway rat and one grey squirrel were non-lethally struck by the trap. One deer mouse appeared to trigger the trap without obvious injury. In conclusion, the Goodnature® A24 rat trap is a relatively humane alternative to rodenticide poisons for mice in these circumstances, but further research is needed to evaluate the humaneness and efficacy for rats.

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Predicting health outcomes and sale price of male dairy calves undergoing long distance transportation (2020)

Male dairy calves are often marketed at a young age when they are vulnerable to health and welfare problems. This study described the condition of male dairy calves before transportation and evaluated factors associated with selling price at an auction market and health outcomes at two calf-rearing facilities (calf growers). Male calves were evaluated at their dairy farm of origin, at an auction market, and after long-distance transportation to a calf grower. Measures of calf condition included a standardized health examination, age, heart girth circumference (HG), and serum total protein as an indication of failure of transfer of passive immunity (FTPI). Selling price at the auction, and treatments for diarrhea or bovine respiratory disease (BRD), along with all mortalities, were recorded during the first 2 wk after arrival at a calf grower. A McNemar Test was used to determine if health deteriorated after transportation and regression analysis was used to evaluate the effects of calf condition on selling price and health outcomes. Large variation in calf condition before transportation was found among dairy farms, with a median prevalence of 17% diarrhea, 2% BRD, 9% navel disease, and 12% FTPI. Calves were transported at a median (interquartile range) age of 5 (3-7) d, with a mean ± SD heart girth circumference of 82 ± 4 cm. Calves observed at auction market with beef genetics that had a large HG and bright, alert attitude sold for a higher price. Immediately after transportation to the calf grower, a greater proportion of calves had an elevated body temperature and a lower proportion had diarrhea, possibly due to dehydration. Calves with FTPI were more likely to develop a depressed attitude after transportation. In the first 2 wk after arrival, 23% of calves were treated for diarrhea, 44% were treated for BRD, and 3.9% died. Important risk factors for diarrhea treatment included small HG and navel disease, and calves with a depressed attitude were more likely to die. These findings indicate there is a need for improvement in the condition of male dairy calves to protect their health and welfare and increase their economic value.

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The effect of animal shelter sound on cat behaviour and welfare (2020)

This study assessed how sound in an animal shelter affects cat behaviour. Singly housed cats (n=98) were observed over 5 months. Fear-related and maintenance-related behaviour were recorded for 30-minute periods on weekdays (AM 10:00-10:30, PM 20:00-20:30) or weekends (AM 7:00-7:30, PM 19:00-19:30) daily from admittance for 10 days or until removed. Cats observed both AM and PM on 2 or more weekdays were used for analysis (n=70). Behaviour, plus presence of sound (classified by the source), was recorded using instantaneous and one-zero sampling with 15-second intervals. Each 30-minute observation period was classified as “quiet” or “loud” if the sound was above or below (respectively) the median for all periods at the same time of day. Data were analyzed by non-parametric Wilcoxon signed-rank tests for differences in behaviour between AM and PM periods. Kruskal-Wallis tests were used to test differences between age groups, source of cats, and Asilomar Accords. Mann-Whitney U tests were used to test differences in fear and maintenance behaviour between males and females. Cats varied widely in the amount of fear and maintenance behaviour they performed. Some spent all their observed time in fear behaviour (especially hiding) and no maintenance behaviour, while others showed no fear behaviour and spent up to 25% of observation intervals in maintenance behaviours. AM periods consistently had much more sound than PM. Cats showed more fear behaviour (p
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Use and perceptions of the Emergency Slaughter Program in British Columbia (2017)

When dealing with acutely injured or non-ambulatory dairy cows, dairy producers in British Columbia must decide whether to treat, ship, euthanize, or use the Emergency Slaughter Program (ESP). This thesis focused on the last of these options. The specific injuries and conditions that result in ESP use are unknown, although identification of these reasons could allow additional monitoring of cows when they may be vulnerable to emergency slaughter, and determine the most appropriate reasons for ESP use. Analysis of 812 ante-mortem inspection documents found that a large proportion of cows in the ESP were non-ambulatory (63%) or had sustained what were likely calving-related injuries (37%). Two distinct uses for the ESP emerged including 1) traumatic incidents (i.e. emergencies) such as a fractured femur and 2) ‘inhumane to transport’, a category that likely includes non-emergencies such as lameness where cows were not necessarily in acute distress but could not be transported humanely. Anecdotal reports suggest that the ESP may be controversial among dairy industry professionals, but to date the overall perceptions including concerns and benefits of the program are unknown. Understanding these perceptions can be used to provide recommendations for improving the ESP particularly in situations where cow welfare is compromised and individuals must make decisions in potentially uncertain and unwanted situations. Interviews and focus groups with 40 dairy industry professionals revealed positive and negative perceptions of the ESP influenced by 1) an individual’s values, 2) the perceived operational legitimacy of the ESP and 3) overarching concerns about the dairy industry. Resulting recommendations for the ESP include: 1) clarification of cow conditions that warrant the use of the ESP for non-emergency situations, 2) additional training for veterinarians on ante-mortem inspection, 3) specification of precise timing parameters for when the ESP can be used, 4) the use of proper equipment and procedures that ensure meat quality and hygiene of carcasses, 5) added collaboration between slaughterhouses, transporters, veterinarians, producers and the dairy industry to allow the appropriate use of the ESP in other parts of British Columbia and 6) proactive culling and the use of on-farm protocols for making end-of-life decisions.

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Hand-rearing Harbour Seal Pups (Phoca vitulina): The Effect of Diet and Supplementary Heat on Growth and Survival (2010)

Hundreds of stranded harbour seals pups (Phoca vitulina) are brought to wildlife rescue centres every year, often unweaned and in poor body condition. Typical hand-rearing diets include artificial milk-replacers and diets based on macerated fish, both normally fed via gavage. Mortality rates for these animals can be high and weight gains on artificial formulas are low. This study was designed to determine the effect of the following treatments on the growth and survival of captive orphaned seals: (1) feeding pups an artificial milk-replacer versus a fish-based formula; and (2) the provision of supplementary heat. Pups admitted to the facility in summer 2007 (n=145) and 2008 (n=98) were randomly assigned to one of two diets and fed until weaning at roughly 20 days of age. In 2008, 25 pups were also provided with a supplementary heat source. Diet and heat treatments were compared using average daily gain (ADG) and mortality rates. In 2007, with pups fed formulas at 8% of body weight per day, pups fed milk-replacer gained more (43 g/d ± 12, mean ± SEM) than those fed fish-formula (loss of 13 g/d ± 6; p0.05) or survival rate (p>0.05) but did show increased heat-seeking behaviour at ambient temperatures below 16°C (p
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