VTS257

2.  Regurgitation
 Aspirationof rumen contents
 Bloat, compromises breathing
 Inadequate ventilation
 Due to drugs relaxing the
pharyngoesophageal and
gastroesophageal sphincters and
suppressing the swallowing reflex.
Anesthesia also decreases gut motility

3.  Recommendations
- Withhold feed prior to general anesthesia
- Intubate with a cuffed endotracheal tube
- Assist or control ventilation with 100%
Oxygen
- Maintain in lateral recumbency only when
necessary. Sternal recumbency allows
eructation and facilitates ventilation

4.  Potential problems:
- External pressure from improper
positioning or poor perfusion can produce
myopathy
- Neuropathy due to pressure

5.  Proper positioning
 Padding all pressure points
 Lower forelimb stretched forward to avoid
radial nerve paralysis in lateral recumbency
 Upper limbs supported at height of proximal
joint in lateral recumbency
 Support circulating blood pressure and
volume when necessary ( maint 10ml/kg/hr)
 Maintain light anesthesia

6.  Potential problems
- Hypotheria
- Immature liver and kidneys
- Hypoglycemia
 Recommendations
- Heating pad used with caution
- Dextrose in fluids ( 2.5% dextrose/LRS)
- Avoid xylazine and barbituates
- Recommend isoflurane
- Nursing up to anesthesia and as soon after
as they can swallow
- Diazepam for sedation and premed

7.  Potential problems
- Strong laryngeal reflex
- Laryngeal spasm
- Aspiration
 Recommendations
- Stiffer clear plastic endotracheal tubes
- Stylets are useful, laryngoscopes
- Full extension of head and neck for full
visualization

8. - Suction saliva if necessary
- Lidocaine sparingly if needed for
laryngospasm
- Intubate and extubate in sternal
recumbency
- Extubate only if swallowing
- Pull endotracheal tube to larynx before
deflating cuff

9. Xylazine
- One tenth of equine dose IV
- Low conc. 20 mg/ml
- Smaller ruminants dilute to 1 mg/ml
- Goats are more sensitive than sheep
- Bulls are more sensitive than cows
- .02-.1 mg/kg IV
- Yohimbine .1 mg/kg, give ½ dose slowly
and repeat if necessary

10.  Xylazine/ketamine
- Xylazine .02 -.08 mg/kg IV, wait 5 minutes
and apply casting rope and halter to assist
in to sternal recumbency
- Ketamine- 2-4 mg/kg IV good induction in
healthy animals

11.  Xylazine-ketamine-guaifenesin
- 50 mg xylazine
- 500 mg ketamine in 500 ml of 5%
guaifenesin
- .5-1 mg/kg/hour max 1 liter of solution per
hour

12.  Considerations of IV maintenance
- Intubation may be necessary to prevent
regurgitation and aspiration
- Drug overdose may cause apnea
- Respiration may need to be assisted
- Limited anesthetic plane
- To be used following xylazine, ketamine
induction if needed
- Used in adults > 300 lbs

13. - Not recommended for juveniles or small
ruminants
- Use only 5% guiafenesin, 10% causes
RBC hemolysis
- IV necessary as guiafenesin is very
irritating if perivascular

14.  Sheep and goats
- Withhold food 12-24 hours
- Don’t withhold water, just avoid excessive
intake
 Calves, lambs, kids
- Withhold food 2-4 hours
- Don’t prevent water of prevent nursing
- Calves, lambs and kids less than 1 month
of age are monogastric and less prone to
regurgitation

15.  Adult cows and bulls
- Withhold food for 36-48 hours
- Withhold water for 13 hours
- Bradicardia may occur due to withholding
food

16.  Recommendations
- Individual variation- .5-2% halothane or 1-2%
isoflurane
- Monitor pulse quality, heart rate, respiratory
rate
- Palpebral reflex should be maintained. Bovine
eye rotates ventrally and medially in light
anesthesia
- Ventilation may need assisstance
- Periods of apnea are common
a. Verify anesthesia is not excessive
b. Assist ventilation for gas exchange

17. 1. xylazine/ketamine IM
- Xylazine .08-1 mg/kg wait 10 minutes for
sedation and give ketamine 8-10 mg/kg Im
- Adv:
a. Good induction in healthy adults when IV
access is not possible
b. Longer duration of anesthesia than with
IV inductions to facilitate induction

18. - Disadv
a. hypotension, respiratory depression
b. Sting of IM ketamine
c. Not recommended for >300 lbs due to
volume needed
d. Goats sensitive to xylazine

19. 2. 5% guaifensesin/ketamine IV
- Mix 1 mg of ketamine per 1 ml guaifenesin
solution
- Dose at .5-1 ml/kg
- Wait max 1 minute for effect
- Maintain sternal for intubation
- Adv:
a. No premed necessary
b. Titrate to effect if necessary

20. - disadv:
a. IV catheter necessary due to guaifenesin
b. GG can cause RBC hemolysis

21. 3. Diazepam/ketamine
- Diazepam .1-.2 mg/kg IV wait 5
minutes, ketamine 2.2-4.4 mg/kg IV
- Adv:
a. Good induction for neonates, small
ruminants, and debilitated
b. No cardiovascular depression at these
doses
c. May mask with isoflurane also

22. - disadv:
a. Diazepam may cause
excitement, especially in adults
4. xylazine/ketamine
- Xylazine .08-.1 mg/kg wait for sedation
and place IV catheter, ketamine 2-4 mg/kg
IV
- Adv: good induction in healthy animals

23. 1. Phenylbutazone- PBZ or Bute
- injectable, tablets, oral paste
- NOTE: must be given IV only by injection.
Administered BID. Causes severe tissue
reaction, necrosis if administered
perivascular, intramuscular, subcutaneous
- Comments: used commonly for
musculoskeletal pain at 1-4 mg/lb
- Chronic use and or high dose results in
ulceration of GI tract

24. 2. Flunixin meglumine ( banamine)
- Injectable, oral paste
- Injectable must be given IV or IM.
Administered BID or TID. Potent analgesic
may mask a surgical colic. Binds
endotoxin. Chronic use and or high dose
results in ulceration of GI tract or renal
failure

25. 3. Ketoprofen ( ketofen)
- Injectable, human formulation ( alleve) has
been given orally but not approved route of
administration in animals.
Absorption, excretion data unavailable.
- Given IM SID

26. 4. Diclofenac ( surpass)
- Topical cream to be rubbed over affected
areas

27. 1. Acepromazine
- Injectable, tables
- Tranquilizers, NOTE: do not administer this
medication to an already excited, agitated
animal. It may create hyper exciteability

28. 2. Xlazine ( rompun)
- Injectable
- Potent sedative and analgesic which may
be administered IV or IM
- Ruminants highly sensitive, use 1/10 the
horse dose
- In horses, be aware that no matter how
drunk the horse looks, it is capable of
kicking violently and accurately. Never trust
xylazine behind the navel

29. 3. Butorphanol ( torbugesic)
- Injectable
- Commonly used to manage colic pain.
May be administered IV or IM
4. Detomidine ( dormosedan)
- Injectable
- Commonly used to manage colic pain or
for procedures requiring profound sedation

30.  Due to complex bacterial ecosystem in the
ruminant and horses GI tract, there are few
antibiotics which may be safely and or
effectively administered orally.
 In production animals always confirm
withdrawal time before administration

31.  Glucosamine/chondroitin sulfate (
cosequin)
- Powder
- Often requires 30-60 days administration
before benefits are observed.
- Many cheaper, copycat products are
available over the counter but are less
effective

32. 1. Polyglycosylated aminoglycan ( adequan)
- Injectable IM or intra articulare
- For treatment and or minimization of wear
and tear lesions of articular cartilage
2. Hyaluronic acid ( legend)
- Single dose injectable for intra articular use

33. 3. clenbuterol- ventipulmin
- Oral syrup
- Bronchodilator for COPD, treatment of
lower airway diseases
4. Omeprazole – gastroguard
- Oral paste
- For treatment of equine gastric ulcers, very
expensive

34. 5. Ponazuril- marquis
- Metered dose oral paste, 28 day regimen
- For treatment of EPM, symptoms may
worsen initially as parasites die in CNS
6. Betamethasone and diuretic
- Bolus
- Used to reduce edema

35.  Ifit is not labeled for use in production
animals, don’t use it in production animals.
 There is more latitude in companion
animals regarding off label use because
the medication should not have the
potential to enter the food chain.

36.  Anesthesia- a state characterized by loss of
sensation
- General anesthesia is a loss of sensation
associated with a loss of consciousness
- Regional anesthesia/local anesthesia, loss of
sensation while consciousness is retained
 Analgesia- state in which stimuli is not
perceived as pain
 Tranquilization/sedation- chemically induced
state of calm

37.  Permits surgery to be safely and humanely
performed on the conscious patient
 Agents: caine family:
lido, carbo, mepivi, bupivi
 Methods of regional anesthesia:
1. Topical
- Lidocaine gel effective only on
mm, disrupted skin
- Proparacaine opthalmic solution

38. 2. Infiltrative “line block”
- Laceration or wound repair
- Dermatologic procedures, skin biopsy
- Castration
- Standing laparatomy
a. Left sided approach- rumenotomy
b. Right sided approach- cesearan section

39. 3. perineural- epineural- anesthetic injected
directly over a nerve, desensitizing distal
areas innervated by that nerve
- Dehorning
- Lameness diagnosis
4. Intra articular- for lameness evaluation

40. 5. Epidural
- Areas desensitized:
anus, perineum, vulva, vagina
- Dystocia correction
- Repair of prolapsed vagina/uterus
- Perineal surgery
- fetotomy

41.  General considerations
- Adequate trained staff must be present to restrain
animal during induction and for surgical positioning
- Minimize contamination of surgical site
a. Bathe animal if necessary to remove fecal material
b. Wrap feet
c. Flush/rinse mouth to prevent material being pushed
by endotracheal tube into lungs
d. Clip and initiate surgical scrub on standing animal to
minimize anesthesia time
e. Note: direct relationship between length of
anesthesia and risk of post anesthesia complications

42.  Regurgitation and or bloat can be serious
complications of general anesthesia
 Elective surgery withhold food for 36-48
hours, withhold water for 12 hours
 Emergency surgery use rumen lavage
 NOTE: most ruminant surgeries can be
performed with regional anesthesia
Equine: elective surgery, withhold food 12
hours, water 6 hours

43. 1. acepromazine- tranquilizer
2. Xylazine
- Profound sedation- head drop and marked
ataxia, up to 1-2 hours
- Despite ataxia, horses can still viciously
and accurately kick.
- Analgesia up to 30 minutes
- Ruminant dose is 1/10 the equine dose

44. 3. detomidine- similar to xylazine but without
ataxia, useful for standing procedures
4. butorphanol- predominant function is
analgesia
5. diazepam- muscle relaxation, sedation
and decreased anxiety

45.  Masking down with inhalation agent
- Patient selection based on size, weight, ability to
tolerate physical restraint
- Risk of injury to patient and or staff during
excitement phase of induction
 Injectable induction- loss of consciousness and
muscle relaxation
- thiobarbituates, ultra short acting 5-15 minutes
- Ketamine/tiletamine- dissociative anesthetics
- Guiafenesin- muscle relaxant, used in conjunction
with another induction agent

46.  Endotracheal
1. cattle/horses- blind intubation, fully
extend head, align with cervical spine
2. Swine- very difficult, must use
laryngoscope
3. Goats/sheep- virtually never place on gas
anesthesia, value of animal vs. cost of
procedure

47.  Isoflurane- about 3.5%
 Oxygen delivery- 1 liter/250 lb body
weight, minimum flow 3 liters per minute
 Fluids/electrolyte replacement
- Maintenance 3-5 ml/lb/hr
- Replacements
a. Blood loss <40% administer 3 ml
crystalloid solution for each ml blood lost(
in addition to maintenance needs)
b. Blood loss >40% transfusion required

48.  Indications
a. PCV <20%, HbB < 5 g/dl
b. Massive >40% total blood volume
hemorrhage
 Donor selection
- Cross match with agglutination and lysis
tests, critical when multiple transfusions
are performed
- Universal donor is adult male that has
never received a transfusion

49.  Heart rate
- Cattle 60-80 ( < 48 trouble)
- Horses 30-48 ( <28 trouble)
- Swine 60-100 ( < 50 trouble)
 Pulse quality/blood pressure assessment
- Direct palpation
- Direct measurement of arterial blood
pressure, cannulation, catheterization
- Mean arterial blood pressure 80-110 mm
Hg ( <60 or > 160 trouble)

50.  Respiration rate
- Spontaneous respiration 6-12 breaths per
minute
- Mechanical ventilation
a. Assisted requires spontaneous respiratory
effort
b. Controlled does not require spontaneous
respiratory effort
c. Assisted kicks into controlled when
ventilation level falls below a certain level

51.  Capillaryrefill time < 2 seconds
 Corneal reflex- not applicable to
swine, horses and ruminants only
a. Hyperractive-
pain, hypotension, hypoxia, ketamine
administration, inadequate plane of
anesthesia
b. Hyporeactive- CNS
depression, excessively deep plane of
anesthesia
NOTE: you can wear out this reflex by

52.  Paralysis- from direct pressure to
superficial nerves
a. Facial paralysis- always remove halter
after anesthetic induction
b. Radial nerve paralysis- inability to
advance the limb, positioning of limbs
during lateral recumbency is critical

53.  Myositis/rhabdomyolysis
a. Pressure hypotension ( sustain MAP at
<60 mm Hg)
b. Padding inadequate between animal and
surgery table permits crushing of down
muscles by animals body
weight, resulting in localized ischemia
c. Position: down forelimb should be
advanced and up limbs limbs supported

54.  Malignant hyperthermia
- Horses and swine
- Monitor body temperature during
anesthesia
- Body temperature > 106

55.  Ruminants
- Sternal recumbency
- Extubate only when active swallow reflex
is present
 Horses
- Prone to violent recovery, require close
monitoring, possibly physical restraine
- Laryngeal spasm at extubation,
tracheotomy kit should be kept in proximity
of all equine recovery skills

56.  Considerations
a. Safety of personnel
b. Aesthetics
c. Carcass disposal

57.  Techniques
- Medication option
a. To sedate or not
b. Euthanasia solution +/- succinylcholine
(paralytic agent)
c. Barbituate and phenytoin ( beuthanasia)
d. Vortech CII
e. Sleep away CII
- Captive or live bolt bullet

58.  Carcass disposal
- Local regulations/zoning restrictions may
dictate options
- Animal disposal companies
- Burial
- Cremation
- Landfill
- Zoos/wildlife parks will not accept animals
euthanized with barbituates, carcass must
be dressed out