Emma M. Malcolm

Bio: Emma M. Malcolm is an academic researcher from Newcastle University. The author has contributed to research in topics: Nicotine & Nicotinic agonist. The author has an hindex of 6, co-authored 6 publications receiving 127 citations.

The Assessment of Facial Expressions in Piglets Undergoing Tail Docking and Castration: Toward the Development of the Piglet Grimace Scale.

Abstract: Many piglets are exposed to potentially painful husbandry procedures within the first week of life, including tail docking and castration, without the provision of either anaesthesia or analgesia The assessment methods used to evaluate pain experienced by piglets are often affected by low specificity and practical limitations, prompting the investigation of alternative methodologies The assessment of changes in facial expression following a painful event has been successfully applied to several species The objective of this pilot study was to evaluate the utility of a Grimace Scale applied to neonatal pigs to evaluate pain evoked by tail docking and castration Eight female piglets, sus scrofa domesticus (Landrace/Large White X synthetic sire line) underwent tail docking and 15 male piglets (75% Large White and 25% Belgian Landrace) were exposed to the castration procedure Clear images of the faces of the piglets were collected immediately pre- and post-procedure The images were used by experienced observers to identify Facial Action Units (FAU) which changed in individuals over this period and a scoring scale was depicted in a training manual A set of randomly selected images were then combined in a scorebook, which was evaluated after training by 30 scorers, blind to the treatment The scale for most FAU was used with a high level of consistency across all observers Tail docking induced a significant change (P<005) only in the ‘orbital tightening’ Action Unit, whereas no change in any unit was observed in castrated piglets In this initial stage of development, orbital tightening at least seems to have the potential to be applied to investigate painful conditions in neonatal pigs Nonetheless, more studies are needed to assess its full effectiveness and to evaluate the influence of possible confounds (eg handling stress) on the observed changes in facial expressions

Characterization of short- and long-term mechanical sensitisation following surgical tail amputation in pigs.

Abstract: Commercial pigs are frequently exposed to tail mutilations in the form of preventive husbandry procedures (tail docking) or as a result of abnormal behaviour (tail biting). Although tissue and nerve injuries are well-described causes of pain hypersensitivity in humans and in rodent animal models, there is no information on the changes in local pain sensitivity induced by tail injuries in pigs. To determine the temporal profile of sensitisation, pigs were exposed to surgical tail resections and mechanical nociceptive thresholds (MNT) were measured in the acute (one week post-operatively) and in the long-term (either eight or sixteen weeks post-surgery) phase of recovery. The influence of the degree of amputation on MNTs was also evaluated by comparing three different tail-resection treatments (intact, 'short tail', 'long tail'). A significant reduction in MNTs one week following surgery suggests the occurrence of acute sensitisation. Long-term hypersensitivity was also observed in tail-resected pigs at either two or four months following surgery. Tail amputation in pigs appears to evoke acute and sustained changes in peripheral mechanical sensitivity, which resemble features of neuropathic pain reported in humans and other species and provides new information on implications for the welfare of animals subjected to this type of injury.

Development of a Piglet Grimace Scale to Evaluate Piglet Pain Using Facial Expressions Following Castration and Tail Docking: A Pilot Study.

Abstract: Facial expressions are increasingly being used to assess pain in non-human species, including rodents, horses and lambs. The development of these species-specific grimace scales have allowed for more rapid pain detection, which can lead to better animal welfare if intervention promptly occurs. For grimace scales to ever be used as a stand-alone measure of pain, it is important they correlate with established pain assessment tools, such as behavioral analysis. This preliminary study aimed to determine whether piglets exhibit pain grimacing and if these facial expressions correlate with their behavior. It also assessed and compared the behavior of boar piglets given an analgesic and topical anesthetic prior to surgical castration and tail docking to piglets that did not receive anything for pain relief. Five-day-old male Yorkshire piglets (n = 19) from four pens were randomly assigned, within their pen, to one of five possible treatments: meloxicam (0.4mg/kg, intramuscularly) + EMLA® cream, meloxicam (0.4mg/kg, intramuscularly) + non-medicated cream, saline (intramuscularly) + EMLA® cream, saline (intramuscularly) + non-medicated cream or no treatment prior to surgical castration and tail docking. Piglet behaviors were video recorded for 8h immediately after castration, as well as for 1h at 24 hours pre- and post-castration. Their individual behaviors were scored continuously for the first 15mins of every hour of video collected. Facial images were also captured across all time points. A Piglet Grimace Scale (PGS) was developed and used by two observers blinded to treatment, time and procedure to score over 600 piglet faces. All piglets displayed significant behavioral changes up to 7h post-castration when compared to baseline, and the use of meloxicam and EMLA® cream was not associated with a reduction in painful behaviors. Significantly higher PGS scores were noted at 0, 3, 4, and 5h post-castration when compared to PGS scores at 7h and there was no effect of treatment. PGS scores significantly correlated with piglet behavioral activity. The results suggest that the Piglet Grimace Scale may have utility for pain evaluation in neonatal pigs.

Early Neonatal Pain-A Review of Clinical and Experimental Implications on Painful Conditions Later in Life.

Abstract: Modern health care has brought our society innumerable benefits but has also introduced the experience of pain very early in life. For example, it is now routine care for newborns to receive various injections or have blood drawn within 24 h of life. For infants who are sick or premature, the pain experiences inherent in the required medical care are frequent and often severe, with neonates requiring intensive care admission encountering approximately fourteen painful procedures daily in the hospital. Given that much of the world has seen a steady increase in preterm births for the last several decades, an ever-growing number of babies experience multiple painful events before even leaving the hospital. These noxious events occur during a critical period of neurodevelopment when the nervous system is very vulnerable due to immaturity and neuroplasticity. Here, we provide a narrative review of the literature pertaining to the idea that early life pain has significant long-term effects on neurosensory, cognition, behavior, pain processing, and health outcomes that persist into childhood and even adulthood. We refer to clinical and pre-clinical studies investigating how early life pain impacts acute pain later in life, focusing on animal model correlates that have been used to better understand this relationship. Current knowledge around the proposed underlying mechanisms responsible for the long-lasting consequences of neonatal pain, its neurobiological and behavioral effects, and its influence on later pain states are discussed. We conclude by highlighting that another important consequence of early life pain may be the impact it has on later chronic pain states-an area of research that has received little attention.

A Review of Pain Assessment in Pigs

Abstract: There is a moral obligation to minimize pain in pigs used for human benefit. In livestock production pigs experience pain caused by management procedures, e.g. castration, and tail docking, injuries from fighting or poor housing conditions, “management diseases” like mastitis or Streptococcal meningitis, and at parturition. Pigs used in biomedical research undergo procedures which are regarded as painful in humans, but do not receive similar levels of analgesia, and pet pigs also experience potentially painful conditions. In all contexts, accurate pain assessment is a prerequisite in: a) the estimation of the welfare consequences of noxious interventions; and b) the development of more effective pain mitigation strategies. This narrative review identifies the sources of pain in pigs, discusses the various assessment measures currently available, and proposes directions for future investigation.