The management of chronic pain in companion animals is an area in which there is a significant therapeutic void. In many cases professionals are unaware of the appropriate approach to manage chronic pain, despite the wide range of pharmacological, surgical and physical therapeutic options that act directly on the pain pathways. Recent discoveries in the area of pain pathways have opened many avenues for the management of chronic pain. The goal of this book is to present this new knowledge in the context of the small animal clinic.
Contents
1. What is chronic pain?
Introduction
Nociception
Transmission
Anatomy of nerve pathways
Transduction: neurotransmitters involved in chronic pain
Cellular metabolic mechanisms of chronic pain
Perception and classification of chronic pain
Pain modulation process
Spinal control
Supraspinal control
Cortical control
Pain chronification
2. Diagnosis of chronic pain syndrome
Introduction
Stress
Behavioural changes in states of continuous pain
Diagnostic approach for a patient with pain
Detailed anamnesis
Physical examination
Blood test
Orientative analytical parameters
Complementary diagnostic techniques
Thermography
Techniques for assessing neurophysiological function
Pain scales used in animals
3. Treatment of chronic pain
Introduction
Pharmacological therapy
Anti-inflammatories
Nonsteroidal anti-inflammatory drugs
Corticosteroids
Opioids
Mechanism of action of opioids
Routes of opioid administration
Opioids used in veterinary medicine
Antidepressants
Tricyclic antidepressants
Selective serotonin reuptake inhibitors
Selective serotonin–noradrenaline reuptake inhibitors
Anticonvulsants
Amantadine
Growth factors
Local anaesthetics
Routes of administration
Most commonly used drugs
α-adrenergic receptor agonists
Medetomidine
Dexmedetomidine
Cannabinoids
Capsaicin
Ketamine
Routes of administration
Experimental drugs
4. Types of chronic pain
Introduction
Visceral pain
Chronic pancreatitis
Chronic renal failure
Uraemic polyneuropathy
Osteoarthritis: joint pain
Pain due to cancer
Analgesic drugs in oncology
Anti-inflammatories: NSAIDs and corticosteroids
Analgesics
Local anaesthetics
Antiemetics
Anticonvulsants
NMDA receptor antagonists
Bisphosphonates
Other drugs
Geriatric pain
Analgesic drugs in geriatric patients
Diabetic neuropathy
Treatment of diabetic neuropathy
Joint pain
Treatment of joint pain
Joint stress stage
Bone inflammation phase
Bone reorganisation stage
Degenerative stage
Radicular pain
Treatment of radicular pain
Corticosteroids
Opioids
Muscle relaxants
NSAIDs
Local anaesthetics
Neurolytic agents
Adjuvant analgesics
Other therapies
5. Interventional therapies
Introduction
Ablative techniques
Peripheral neurectomy
Rhizolysis
Facet rhizolysis
Cordotomy
Dorsal root entry zone (DREZ) lesion
Decompression techniques
Discolysis
Neuromodulatory techniques
Neurostimulation
Spinal infusion
Electrotherapy
Transcutaneous electrical neurostimulation (TENS)
Interferential currents
Ultrasound
Shockwave therapy
Diathermy
Neuromuscular therapy
6. Functional recovery of a painful limb. Case descriptions
Introduction
Case 1 Shiba. Golden Retriever, aged 14 years
Case 2 Terry. A mixed breed, 30-kg dog with leishmaniasis
Case 3 Pepa. Yorkshire Terrier, aged 5 years
Case 4 Admiral. Labrador, aged 2 years
Case 5 Terry. Golden Retriever, aged 10 years
Case 6 Miko. Dachshund, aged 6 years
