Anesthesia of ruminants, camelids and swine Flashcards
What are concerns for ruminants and anesthesia
Biggest anaesthetic concern = regurgitation and aspiration of rumen or stomach contents
Bloat
Mainly alpha2-agonists and ketamine
Different methods of tracheal intubation
Avoid
Anticholinergics
Acepromazine
Herbivores MUST breathe through nose
Regurgitation and aspiration in ruminants
Neonatal ruminants do not chew cud – treat like a ‘dog’
Produce copious amounts of saliva
Anesthesia produces loss of protective airway reflexes
Ruminants are prone to regurgitation and inhalation of rumen contents
General anaesthesia performed ‘on the farm’ may not enable reliable airway protection
Aspiration causes severe lung damage, lack of oxygen and death
Prevention of aspiration and bloat for ruminants
Fast for 24-48 hours with removal of water 6-24 hours in adult cattle
Smaller ruminants can decrease time slightly
Reduces rumen contents
Position head and neck to allow drainage away from airway
With endotracheal tube
Remove when holding head up
What is bloat caused by
Fermentation continuous and eructation is not possible
Rumen distends with gas
Pressure placed on the diaphragm and thoracic cavity
Lack of oxygen and lung ventilation
Decreased flow of blood back to heart
Poor blood circulation
Treatment difficult
How do you sedate a small camilid
Dose alpha2-agonist according to temperament:
Xylazine (0.025–1.0 mg/kg IV/IM)
Reverse with atipamezole (25–100 mcg/kg IM)
Can use Butorphanol (0.05–0.2 mg/kg IV/IM)
Can add Ketamine 1–2 mg/kg IV for anesthesia
What is llama lulaby and how to dose
100mg xylazine (1mL;100mg/mL)
10 mg butorphanol (1ml;10mg/mL)
1000mg ketamine (1mL;100mg/mL)
Dose
1mL/45 kg for sedation
1mL/15-20 kg for anesthesia
20mins
May need local analgesia for surgery
How do you intubate a camelid
Difficult because of anatomy
Narrow gape
Mound on dorsum of tongue
Elongated soft palate
How do you monitor and recover a camilid
Monitoring depth of anaesthesia
Loss of ventral palpebral reflex
Dorsal palpebral reflex still remains
Position into sternal recumbency for recovery
Keep intubated until they can hold head up (neck tone) and are able to swallow
Suction and regurgitation material from pharynx
Check for nasal breathing after extubation
What sedatives can you use in sheeps/goats
Alpha2-agonists
High dose can cause recumbency
Goats can be sensitive to xylazine
0.02-0.1mg/kg IV/IM (1/10th the dose you would use in a horse)
Sheep
0.05-0.2 mg/kg IV/IM
Can cause hypoxemia when breathing air – supplement oxygen if possible
Incidences of pulmonary edema in some sheep
Xylazine causes increases in uterine tone in last trimester of pregnancy
Abortion possible
Can use detomidine (10-20mcg/kg IV/IM)
Can use dexmedetomidine (2-5 mcg/kg IV/IM)
How do you maintain sedation in goats/sheep
Induce anesthesia with propofol, alfaxalone or ketamine/diazepam
Use butorphanol as an analgesic
Propofol infusion (0.4 mg/kg/min IV)
Triple drip mic (cattle/sheep) - GGE/xylazine/ketamine
1 liter 5% guaifenesin (50 mg/ml)
100 mg xylazine (0.1mg/ml)
1000 mg ketamine (1mg/ml)
Administer at a rate of approx 2ml/kg/hr IV to effect
What is different with goats/sheeps breathing
Larynx more caudal and gape narrow
Typically develop tachypnea, small tidal volume
May require higher vaporizer settings
Beware of hypercapnia
How do you intubate a hseep/goat
Place in sternal or lateral
Use soft ropes to open mouth
Pull more on upper jaw to have airway in a straight line
Pull tongue forward
Spray larynx with lidocaine
Use a tube with a stylet
Place using a good laryngoscope
May have to place blade on epiglottis
How do you monitor sheep/goats durign GA
Eye signs in sheep, goats and cattle
Rotated eye = light surgical place
Central eye = deep surgical plane
Palpebral reflex
Present in light plane of anaesthesia
Nystagmus– not common
Not useful
May swallow at light surgical plane
how do you sedate a mature cow
Alpha2 - agonists commonly used:
Xylazine (0.05– 0.2 mg/kg IV/IM)
Detomidine (10–20 mcg/kg IV/IM)
Vocalize and high doses can result in recumbency
Xylazine can cause abortion in third trimester
Add BUTORPHANOL (0.05–0.1 mg/kg IV) for analgesia
Induce with Ketamine (2 mg/kg IV)
Can use ‘Triple–Drip’ to maintain anesthesia
Can use inhalational anesthesia after intubation
how do you recover a mature cattle
Usually smooth
Guide up with halter rope and tail hold
Can reverse alpha2-agonists
25-100mcg/kg atipamezole IM
Leave tube in palace until able to hold up head (neck tone) and eructate
What are common anesthetic issues with small pigs
Prone to hypothermia
Acepromazine and azaperone promote heat loss
Usually do not fast if suckling
Otherwise fasting rules comparable to the dog
Sedate with drugs given IM
Use inhalational for maintenance by mask if necessary
Calculate max volume of local analgesics
Intratesticular lidocaine
How do you anesthetize small pigs
Same fasting as dog/cat
Can sedate IM (in order of increasing sedation):
Xylazine (2 mg/kg)–alone is not reliable
Azaperone (2–4 mg/kg) + Butorphanol (0.2 mg/kg)
Dexmedetomidine (20–30 mcg/kg) + Butorphanol (0.2 mg/kg)
Xylazine (1–2 mg/kg) + Ketamine (5–10 mg/kg) + Butorphanol (0.2 mg/kg) +/- Midazolam (0.2 mg/kg)
Dexmedetomidine (20–30 mcg/kg) + Ketamine (5–10 mg/kg) + Butorphanol (0.2 mg/kg) +/- Midazolam (0.2 mg/kg)
Induction can be performed with any injectable anesthetic
IV options: Cephalic, Auricular
How do you intubate a pig
Can use lidocaine spray
Require stylets and a good laryngoscope
Range of endotracheal tube sizes
Mucosa is delicate and will bleed profusely
Can try any body position–lateral considered the most difficult
Consider pre-oxygenation
Ensure adequate anesthetic depth
Laryngeal anatomy can make intubation difficult, right angle bend
Insert tube with stylet halfway through the larynx, pull out stylet and push tube into larynx with 180 degree turn
How do you sedate a pot belly pig
High fat/body mass ratio
Peripheral venous access difficult
Use minimum 3cm needle for IM injection
Sedation (“pig potion”)
Dexmedetomidine 20-30 mcg/kg
(Midazolam 0.3mg/kg)
Butorphanol 0.3mg/kg
Or hydromorphone 0.1mg/kg
What do you use for pot belly pigs anaesthesia
Add ketamine 5-10 mg/kg/hr IM/IV
Mask with inhalational agent
