Assessing post-operative pain in rodents
“The question is not, can they reason? nor, can they talk? but, can they suffer?” goes the famous saying by the 18th century philosopher (Bentham 1789, as cited in Kuhse and Singer 1999). But how exactly can we tell, let alone quantify, if an animal is suffering, is in a state of pain or distress? With the current consensus in the scientific community regarding animals’ capability of experiencing pain (Hawkins 2002), the next step is to reliably identify and evaluate negative emotional states in animals, in order to alleviate their suffering. There are numerous reasons to do this, from scientific and financial interests to legal and moral obligations. All the more so when the animal is in pain of our own infliction, such as the case of laboratory animals (Weary et al. 2006). In 2015 over 2,000,000 experimental procedures were performed on laboratory animals in the UK alone, ranging from mild to severe according to the amount of pain that an animal may suffer as a consequence (Home Office 2016). A 2005 literature review found that the overall use of post-operative analgesics for laboratory rodents was low, and suggested a connection with poor pain assessment methods and overlooking behavioural marks (Richardson and Flecknell 2005, Roughan and Flecknell 2003).
As there is no gold standard for assessing pain in existence, there is a growing need for trustworthy ways to assess pain, that can potentially be utilized by