Lecture 11 Ruminant and Camelid Anesthesia Flashcards
1
Q
What are some indications for doing general anesthesia in ruminants
A
- umbilical surg.,
- penile surgery,
- cryptorchidism,
- fractures,
- septic joints,
- tube cystotomy,
- research
2
Q
What are some risks ruminants have when undergoing general anesthesia
A
- ruminal reflux,
- bloat etc.
3
Q
What are the 4 special concerns of ruminants
A
- Salivation throughout anesthesia
- Fluid loss, risk of airway occlusion & aspiration
- Rumen
- Airway protection
- ET intubation recommended, usually easy but can be challenging
- Hypoventilation under general anesth.
- Mechanical ventilator
4
Q
Why is the rumen a special concern in anesthesia
A
- Never completely empty
- Passive reflux and aspiration pneumonia
- No eructation under anesthesia
- Bloat & pressure on lungs ® hypoxemia
- Stomach tube to decompress/trochar
- Large & heavy
- Pressure on lungs when recumbent
5
Q
Why fast ruminents?
A
–Reduces rumen size
–Decreases microbial activity/gas production
6
Q
Patient Preparation in:
- Adult cattle
- Sheep, goats, camelids
- Calves, lambs, kids, crias
A
- Adult cattle
- Withhold food for 24-48 hrs & water 8-12 hrs
- Sheep, goats, camelids
- Withhold food for 24 hrs & water 12 hrs
- Calves, lambs, kids, crias
- Withhold food 2-4 hrs (age?)
7
Q
Side effect of fasting
A
metabolic alkalosis
8
Q
- Premedication advantages
- Disadvantages
A
- Advantages
- Preemptive analgesia, reduces induction/maintenance doses
- Disadvantages
- May increase risk of ruminal reflux once recumbent
9
Q
- Are premedications necessary for ruminents?
- Why or why not?
A
- Often unnecessary
- Reasons:
- Calm animals accept restraint for IV catheter & induction
- Cattle can be strapped to tilt table
10
Q
- What are 2 options for IV access in cattle
- What are special considerations for using each
A
- Jugular vein
- Thick skin: pilot hole with needle or blade to insert catheter
- Auricular vein
- Can’t inject large volumes e.g. guaifenesin
11
Q
IV Access – Sheep & Goats
A
- Jugular vein
- Cephalic vein
12
Q
- Are anticholinergics used as premedications?
- Why or why not?
A
- NOT used
- Salivation does not stop & saliva gets thicker
13
Q
What are premedication options in ruminants
A
- Acepromazine ± opioid (butorphanol) IV or IM
- Acepromazine + diazepam IV – sheep & goats
- Midazolam + butorphanol IV or IM – sheep & goats
- Xylazine IV or IM
14
Q
What are considerations when using xylazine in ruminants
A
- Hypoxemia in all ruminants
- Sheep can develop pulmonary edema because of their types of macrophages
- Increases myometrial contractions
- Better avoid in last trimester of pregnancy (cattle)
- Breeds sensitivity
- Hereford and Brahman anecdotally more sensitive
- Breed sensitivity also for sheep and goats?
15
Q
How much smaller of a dose of xylazine do you use in ruminants compared to horses
A
use 1/10th the equine dose
16
Q
- What % of xylazine do you use in ruminants?
- Why?
A
- Best to use 2% xylazine
- Extremely sensitive compared to horses