been shown to have minimal adverse cardiovascular effects while the α-2
agonists have been shown to induce moderate to marked changes in heart
rate, blood pressure and cardiac output in both adult horses and foals. In
foals less than 2 weeks of age, diazepam generally provides excellent
sedation and muscle relaxation and based on its cardiopulmonary effects, it is
a logical first choice when a sedative is required. In older healthy foals,
xylazine is recommended as it provides more reliable sedation, however, a
benzodiazepine may be a suitable option in a critically ill foal greater than 2
weeks of age.
Systemic administration of the opioid analgesic butorphanol is suitable for
soft- tissue associated pain while morphine is an appropriate analgesic for
orthopedic injuries.
Optimizing analgesia in the equine patient is always a challenge due in large
part to the side effects of the available analgesic agents. The inclusion of
butorphanol (0.04 mg/kg) IV with either a benzodiazepine or an α-2 agonist
improves the quality of analgesia and sedation of the latter agents with
minimal adverse effects. Butorphanol can also be used on its own. The
author favours giving to effect rather than to a timed dosing plan as absorption
and duration of effect can be so variable.
The administration of butorphanol as a CRI is well tolerated and it is a reliable
adjunct in foals when prolonged sedation is required.
Fentanyl patches are growing in their use, especially in small animal medicine
and the author has had good experience with the use of fentanyl patches in
neonates. The high lipid solubility of the mu agonist, ensures rapid
transdermal uptake. The author aims for one 10mg patch per 150kg of body
weight. One or two 2.5mg patches are placed on the foal (each releasing
25mcg/hr drug). These are replaced every 48-72 hours.
Problems secondary to recumbency
Entropion
Hypoglycaemia
Hypothermia
Patent urachus
Orthopaedic problems
Decreased oxygen tensions
Pressure sores/ulceration
Gastric ulceration
Mare rejection
15-‐18
February
2016
East
London
Convention
Centre,
East
London,
South
Africa
207