How Do Animals Feel Pain?

Question 1

1. Define pain.
2. Six notes to go alongside this.

Answer 1

1. An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.
2. • Pain is always a personal experience that is influenced to varying degrees by biological, psychological and social factors.
     - Pain and nociception are different phenomena. Pain cannot be inferred solely from activity in sensory neurons.
     - Through their life experiences, individuals learn the concept of pain.
     - A person’s report of an experience as pain should be respected.
     - Although pain usually serves an adaptive role, it may have adverse effects on function and social and psychological well-being.
     - Verbal description is only one of several behaviours to express pain; inability to communicate does not negate the possibility that a human or a nonhuman animal experiences pain.

Question 2

Define nociception.

Answer 2

The neural process of encoding noxious stimuli.
– Consequences of encoding may be autonomic (e.g. elevated BP) or behavioural (motor withdrawal reflex or more complex nocifensive behaviour). Pain sensation not necessarily implied.

Question 3

Difference between nociception and pain?

Answer 3

Nociception is the wiring part of the process whereas pain is how the patient interprets nociception.

Question 4

Why is it important to know the difference between nociception and pain?

Answer 4

Nociception is the physiology and it is helpful to understand this for preventing and treating pain.
Pain is what nociception means to the animal.
Pain is an important welfare issue.
Important to know that there can be really different individual / species differences to how pain is manifested so just because an animal is not screaming, doesn’t mean to say that it isn’t pain.

Question 5

What is nociceptive pain?

Answer 5

Pain that arises from actual or threatened damage to non-neural tissue and is due to the activation of nociceptors.
Note: This term is designed to contrast with neuropathic pain. Used to describe pain occurring with a normally functioning somatosensory NS to contrast w/ abnormal function seen in neuropathic pain.

Question 6

1. What is neuropathic pain?
2. How is the term lesion commonly used?
3. How is the term disease commonly used?

Answer 6

1. Pain caused by a lesion or disease of the somatosensory NS.
   Note: Neuropathic pain is a clinical description (not a diagnosis) which requires a demonstrable lesion or a disease that satisfies established neurological diagnostic criteria.
2. The term lesion is commonly used when diagnostic investigations (e.g. imaging, neurophysiology, biopsies, lab tests) reveal an abnormality or when there was obvious trauma.
3. The term disease is commonly used when the underlying cause of the lesion is known (e.g. stroke, vasculitis, diabetes mellitus, genetic abnormality).

Question 7

Why is it important to know the difference between nociceptive and neuropathic pain?

Answer 7

Can make a difference in how you approach pain management / treatment.
Neuropathic pain can be harder to treat.
Pain may be a consequence of a disease process – could be neuropathic pain or nociceptive pain.
For elective surgical procedures, it is important to avoid damaging neural tissue.

Question 8

1. What is hyperalgesia?
2. What is allodynia?

Answer 8

1. Increased pain from a stimulus that normally provokes pain.
2. Pain due to a stimulus that does not normally provoke pain.