Pain in domestic animals and how to assess it: a review

Abstract

ABSTRACT:In recent years more attention has been paid to the issue of pain in animals, particularly in association with increasing awareness of animal welfare. It is therefore necessary for veterinarians to be able recognise unambiguously whether an animal suffers from pain. Adult humans suffering from pain can more or less characterise their painful experiences, including the site and intensity of the pain. However, pain in animals is in some aspects more complex and it can be rather difficult to evaluate the seriousness and impact of painful events. Therefore, in animals we have to recognise the signs of pain according to indirect markers which involve behavioural, physiological and finally clinical responses. Moreover, in particular the behavioural changes associated with pain can be along with the general signs also species-specific, and hardly recognisable (and for an inexperienced observer seemingly unimportant) which makes pain assessment even more complicated. Therefore, the current review formulates definitions of pain, its classification and is focused on methods that may facilitate pain recognition in animals, which is crucial for an effective pain assessment and consequent effective pain management. The review combines recent knowledge with well proven facts concerning pain and furthermore also highlights the author's own research on pain assessment.

Effects of epidural anesthesia with tramadol, ropivacaine or tramadol-ropivacaine combination, in bitches undergoing ovariohysterectomy under anesthesia with isoflurane

“…Other researchers (CARREGARO et al, 2010, POHL et al, 2011ADAMI et al, 2012;MORGAZ et al, 2013) have used the EVA scale in similar studies. The EVA scale is related to the physiological parameters FC and PAS in order to minimize the errors during interpretation (LANDA, 2012). The pain is assessed before and after the administration of the drug by the same observer who was blinded to the treatments (CARREGARO et al, 2010;POHL et al, 2011POHL et al, , 2012PAOLOZZI et al, 2011;SOUZA et al, 2013).…”

“…The assessment of pain in animals is based on both the physiological parameters and the behavioral aspects, and because of their subjectivity, these assessments are difficult to perform (BRONDANI et al, 2004;PAOLOZZI et al, 2011;POHL et al, 2011;LANDA, 2012;MORGAZ et al, 2013). Physiological parameters are critical to the assessment of pain, especially during the transoperative period, and include, among other variables, heart rate (HR), respiratory rate (F), body temperature (T, ºC), and blood pressure (BP) (BRONDANI et al, 2004;LANDA, 2012). Postoperative pain is also diagnosed based on an evaluation of behavioral characteristics, using methods such as the visual analogue scale (VAS).…”

“…Postoperative pain is also diagnosed based on an evaluation of behavioral characteristics, using methods such as the visual analogue scale (VAS). The VAS is a line measuring 10 cm, with marks at the two ends corresponding to no pain and worst pain possible (CARREGARO et al, 2010;POHL et al, 2011;LANDA, 2012;SOUZA et al, 2013;TEIXEIRA et al, 2013). This scale is routinely used in postoperative evaluation of various surgical procedures, one of which is ovariosalpingohysterectomy (OSH) (CARREGARO et al, 2010;POHL et al, 2011;ADAMI et al, 2012;MORGAZ et al, 2013;TEIXEIRA et al, 2013).…”

Pathophysiologic mechanisms of pain in animals A review

“…This pain is recognized by identification of a lesion and characteristics that typically include a well-localized site and an experience described as aching, squeezing, stabbing or throbbing (AMA, 2010). Arthritis and metastatic bone pain are the examples of somatic pain (Landa, 2012).…”

“…According to Landa (2012), clinically, pain can be labelled "nociceptive" if it is inferred that the pain is due to ongoing activation of the nociceptive system by tissue injury. Although neuroplastic changes, such as those underlying tissue sensitization, are clearly involved, nociceptive pain is presumed to occur as a result of the normal activation of the sensory system by noxious stimuli, a process that involves transduction, transmission, modulation and perception (Figure 1) (AMA, 2010).…”