Exotic Pet Analgesia

Question 1

Issues with exotic companion animal medicine

Answer 1

-few studies about basic physiology
-little info on PK and Pharmacodynamics
-Smaller animals tend to have faster metabolic rates

Question 2

Prey species

Answer 2

eg. rabbits, rodents
-most will hide signs of sickness and pain
-may pretend to eat/groom in stressful situations

*observer bias can make studies difficult

Question 3

Pain in small animals

Answer 3

-prey species
-body position/posture
-activity and attitude changes
-unkempt hair coat
-appetite and fecal production
-facial expression= grimace scale *not really useful in exotics

Question 4

Rat grimace scale

Answer 4

-orbital tightening
-nose/cheek flattening
-ear changes (pointed shape)
-whisker changes (move forward away from face and bunch)
-chromodecteria- porpherin pigments around eye

Question 5

Issues with Analgesia studies in rabbits

Answer 5

-dosages based on lab animals
-studies are conducted on young and healthy animals
-short time frames
-small number of animals
-studies don’t usually look at anesthesia

Question 6

Opioid doses

Answer 6

-lower dosages in ferrets than other small mammals (similar to cat)

Question 7

Opioid routes of transmission for exotics

Answer 7

-IM, SC for sedation

-IV, IM, SC for hospitalized patients

-Oral transmucosal= limited absorption in GP but can be administered more often

Question 8

Opioid PK

Answer 8

-Buprenorphine- need 10x dose of car for guinea pigs and chinchillas

-used studies using paw pressure tests

Question 9

NSAID use

Answer 9

-Meloxicam most common
-often need higher doses for ferrets
-half life of 8hrs in rabbits, nothing left after 24hrs, need to administer 2x a day; few negative effects

Question 10

Lidocaine in exotics

Answer 10

-local block and epidural (also includes bupivacaine)
-CRI, alone or in association with other agents
-Toxic dose in rabbits: 4mg/kg
-CRI: 100micrograms/kg/min better analgesia than buprenorphine for spays
-visceral pain

Question 11

Analgesia protocol

Answer 11

-Moderate pain= buprenorphine (has plateau effects)

-intense pain: hydromorphone, morphine, fentanyl

Question 12

Multi modal analgesia plan

Answer 12

-opioid +NSAID

-Opioid +lidocaine CRI in rabbits

Question 13

Avian

Answer 13

-chicken and quails most widely studied (and now psittacines and raptors)

-differences in kidneys and fast metabolism
*renal portal system

Question 14

Pain recognition in birds

Answer 14

-squinting eyes
-feathers are puffy (not close to the body)
-drooping face

Question 15

Avian analgesia

Answer 15

• differences between avian orders
  -historically, birds associated with kappa receptors= butorphanol
  -now unclear of balance between mu and kappa depending on different avian species

Question 16

Opioids in psittacines

Answer 16

1. Butorphanol
   -seem to express more kappa
   -short half life (less than 4hrs) so difficult
   -can extend half life with liposome encapsulated formulation (not commercially available)
2. Tramadol
   -single dose or multiple doses (oral or IV)

Question 17

Opioid use in raptors

Answer 17

More mu receptors
-Hydromorphone will be most effective. significant sedation at high doses (3-6hrs)

-butorphanol- not great

-buprenorphine- effective , similar to hydromorphone
-6hrs; sex differences

-tramadol- GI side effects, less pronounced anti nociceptor effects, lower dosages than HAP

Question 18

NSAIDs in psittacines

Answer 18

-high metabolism, high doses than mammals
-meloxicam most common
-no renal effects

Question 19

NSAIDs in raptors

Answer 19

-metacam

-some NSAIDs have been found to be toxic (Diclofenac, carprofen, flunixin meglumine, phenylbutazone)

Question 20

Reptiles

Answer 20

-feel pain, but don’t necessarily move or show it. Some will show aggression

-slow metabolism (lower dosages, longer duration, slower absorption)
*affected by environment

Question 21

Reptile evidence of pain

Answer 21

-behavioural response to painful stimuli
-ID of pain pathways
-Demonstration of effective analgesia

Question 22

Signs of pain

Answer 22

Chelonians- stretch neck, gape mouth, closing eyes, biting

Snakes- restless, easily startled, agitated, less coiled, tuck away painful area

Lizards- postural changes (arch back, head press, tuck coelom), flick at area

Question 23

Chelonians opioid use

Answer 23

-mu agonists
-morphine most effective (monitor for resp signs; use higher dosages)
-hydromorphone- better than buprenorphine
-tramadol- can be used for analgesia and minimal resp depression

Question 24

Lizards opioids

Answer 24

-Pure mu agonists
-Butophanol not effective analgesia
-use morphine

Question 25

Snakes opioids

Answer 25

-butorphanol
-fentanyl patches

Question 26

Reptiles nsaids

Answer 26

-meloxicam most common
-low dosages and frequencies due to slower metabolism

**efficacy is in question