Chronic Pain Flashcards
Chronic pain behaviour
-aggression/reactivity
-attention seeking
-sleep pattern changes
-loss of normal behaviour
-change in navigation of their environment
-unwillingness to go for walks
-depression
-guarding behaviour
-licking/chewing painful areas
-sudden or excessive scratching
-noise sensitive
-anxiety/fear
What is chronic pain?
Any pain lasting more than 3mths
-no mechanistic switch from acute to chronic
-acute pain states can present chronically
-slow onset
-avoidance masks pain
Behaviour and Pain
-up to 82% of dog and cat behaviours is due to PAIN
Common sources of pain linked to behaviour
-hip, stifle (most common)
-elbow, spine, other joints
-GI
-dental
-dermatological
-ear
Anxiety and pain
Neuro pathways with pain and anxiety/fear is linked
*results in behavioural responses
-Allergies (chronic itch=chronic pain)
How can chronic pain be assessed?
Owner should look for stair navigation, jumping up/down, sleep habits vs restlessness,
-take videos
Animals often won’t show in clinic
Types of chronic pain
- Somatic
- Visceral
- Neuropathic
**can occur concurrently
C-fibres
-unmyelinated (slower)
-chronic
-feel dull, poorly localized persistant pain
A delta fibres
-myelinated (fast)
-acute
-sharp, well localized pain
Somatic pain
-chronic inflammatory pain (musculoskeletal such as OA, burns, trauma, dental pain )
-A delta:C = 1:2
-easier to localized and find spot where it is coming from. BUT as inflammatory mediators increase, can lead to less localization
-inflammatory mediators- persistant inflammatory pain can lead to other types of pain
Treatment of somatic pain
Dull aching throbbing sore pain
-NSAIDs (early stage)
-NGF monoclonal antibody (Solensa/Librela)
-Platelet rich plasma therapy
-ancillary treatments
-nutraceuticals
-multimodal therapy chronically
-allergy treatment
Chronic visceral pain
-A delta:C ratio = 1:10
-visceral afferent fibers travel with parasympathetic nerves (eg. vagus nerve)
-gnawing, squeezing, cramping
-difficult to localized because large overlapping receptor fields
-referred pain is common
Eg. peritonitis, gastric ulceration, irritable bowel syndrome, pancreatitis, cancer
Treatment of chronic visceral pain
-treat inciting cause
-dietary change may help (low CHO, high protein and fat)
-omega 3 fatty acids
-antispasmodic agents
-opioid agonist-antagonists or partial agonists
-NSAIDs, TCAs, SSRIs
Neuropathic pain
-pain started or caused by a primary lesion or dysfunction in peripheral or CNS
*90% of people with spinal cord injury
=hyperalgesia
-difficult to diagnose in animals. Can present in Cancers, chronic inflammatory disease such as OA, interstitial cystitis in cats
-Shooting, burning, electric like sensation, tingling, stabbing= phantom limb pain
Treatment of Neuropathic pain
- Start with NSAIDs
-add analgesic adjuvants like TCAs, serotonin-norE reuptake inhibitors, anticonvulsants, tramadol - Opioids can help. Partial effectiveness
**Multimodal approach more effective than single therapy
