Forms of general anaesthesia in cattle, commonly used drugs and drug combinations

Question 1

General intravenous anesthesia

Answer 1

• Many surgical procedures are performed with local or regional anesthesia, but
• General anesthesia:
o Increased patient comfort
o Improved anesthetic agents, analgesics, and equipment
o Increased experience and knowledge of veterinarians, veterinary anesthesiologists,
and veterinary technicians

Question 2

General intravenous anesthesia

Advantages

Answer 2

• Short induction time
• IV administration with minimal assistance
• Small volumes
• Some products can be administered intramuscularly
• Products are often combined
• Drug mixtures:
o decrease the dose
o the negative effect of individual drugs

Question 3

General intravenous anesthesia

Disadvantages

Answer 3

• The depth of anesthesia is more difficult to control
• Slow recovery, especially when administered IM or SQ
• Drugs are not labeled for use in food producing animals
• Milk and slaughter withdrawal times
• Respiratory support is difficult

Question 4

General intravenous anesthesia

Complications

Answer 4

• Lung capacity of cattle is small, abdominal organs (dorsal or lateral recumbency)
• The cardiac sphincter relaxes during anesthesia → ruminal contents (reflux) into the pharynx
→ aspirated
• Rumen tympany

Question 5

General intravenous anesthesia

Other Considerations

Answer 5

• Accurate weight of the patient
• Rate and dosage → many patient-related factors:
o Excitementofthepatient
o Renalorhepaticdisease
o Metabolicrate
o Pregnancy
• Proper restraint and vein accessibility
o Subcutaneous abdominal vein (milk vein) in the recumbent cow

Question 6

Drugs

Anesthesia terminology

Answer 6

• Sedative: Narcotic agent used to calm a nervous or excited animal
• Analgesia: Relief from pain
• Anesthesia: The loss of sensation and loss of the ability to feel pain
• General anesthesia: The loss of consciousness with decreased sensitivity and with reduced
motor response

Question 7

Drugs

Answer 7

Acepromazine (phenothiazine-based tranquilizers)
Diazepam/midazolam (phenothiazine-based tranquilizers)
Xylazine (alfha2 agonist)
Detomidine (alfha2 agonist)
Ketamine (dissociative anesthetic agent)
Butorphanol (Opiate)
Flunixin Meglamine (NSAID)
Meloxicam (NSAID)

Question 8

Acepromazine (phenothiazine-based tranquilizers)

Answer 8

• Mild sedation
• IM, IV, SQ or PO (higher doses are required for PO)
• Wait a minimum of 15 minutes for effect
• IV dose faster, but more time is required for IM, SQ, or PO use
• Excitable cattle?
• Cattle sedation
★ IV 0.01 to 0.02mg/kg (0.0045 to 0.009 mg/lb)
★ IM 0.03 to 0.05 mg/kg (0.014 to 0.0225 mg/lb)

Question 9

Diazepam/midazolam (phenothiazine-based tranquilizers)

Answer 9

• Sedation and muscle relaxant
• Cattle dose
o Sedation 0.55 to 1.1 mg/kg (0.25 to 0.5 mg/lb) IM or IV

Question 10

Xylazine (alfha2 agonist)

Answer 10

• Potent sedative and analgesic effects
• Cattle: 10 times more sensitive to xylazine than horses
• IV, SQ, or IM
• Onset is longer: IM and SQ (min. 15 minutes)
• Dose and response cattle depends on:
o temperamentofthepatient
o route of administration
• Higher dose: recumbent patient
• Doses
o Mild to moderate sedation: 0.022 to 0.066 mg/kg (0.01 to 0.03 mg/lb)
o Heavy sedation, possible recumbency: 0.11 to 0.165 mg/kg (0.05 to 0.075 mg/lb

Question 11

Detomidine (alfha2 agonist)

Answer 11

• More potent sedative and analgesic agent than xylazine
• Causes more cardio and respiratory depression than xylazine
• Should not be used in cases to cause recumbency
• Dosage not well determined
o IV dose range in cattle: 0.01 to 0.02 mg/kg (0.45 to 0.9 mg/100 lb)
o IM dose range in Cattle: 0.02 to 0.05 mg/kg (0.9 to 2.25 mg/100 lb)

Question 12

Ketamine (dissociative anesthetic agent)

Answer 12

• Analgesic (painkiller) effect → administered in a subanesthetic dose
• Cattle dose: 2.2 mg/kg (1mg/lb) IV after sedation
• Commonly used in combination with xylazine
• Dose may be reduced when used in combination
• Recovery period: tremors, vomit or hypersalivation

Question 13

Butorphanol (Opiate)

Answer 13

• Analgesic (painkiller)
• Does not produce anesthesia
• Cattle dose: 0.02 to 0.025 mg/kg (0.009 to 0.01 mg/lb), 30 to 40 mg total dose
★ Best when used in combination with sedative
★ Cattle may become excitable with butorphanol alone
• In combination with xylazine and ketamine
• In standing animals: + local anesthetics (lidocaine) must be used

Question 14

Flunixin Meglamine (NSAID)

Answer 14

Used as:
• Anti-inflammatory
• Analgesic: to control visceral pain but not for musculoskeletal pain
• Anti-pyretic
• Anti-endotoxin
• No more than 5 days → abomasal ulcers
• Cattle dose 1.1 to 2.2 mg/kg (0.5 to 1.0 mg/lb)
o 1 ml/100 lb IV of 100 mg/ml solution

Question 15

Meloxicam (NSAID)

Answer 15

• Analgesic drug
• IV or PO, but up to 3 days
• Oral route of administration is practical and economical: typically supplied as 15 mg tablets
• Cattle dose 1.0 to 2.0 mg/kg (0.45 to 0.9 mg/lb) orally
• May cause GI ulcers with prolonged use

Question 16

Commonly Used Drug Combinations

Answer 16

Ketamine Stun or K-Stun
IV Recumbent Stun
IM or SQ Recumbent Stun
IV Standing Stun
IM or SQ Standing Stun
5-10-20 Technique

Question 17

Commonly Used Drug Combinations

Ketamine Stun or K-Stun

Answer 17

• Patients: awake, mild pain, but more cooperative
• Two different techniques
    o Standingtechniques:largeruminants
    o Recumbenttechniques:smallruminants
• Effect depends upon:
    o Dose
    o Route
    o Temperament
• May be administered IV, IM, or SQ
    o IV: rapid onset, higher analgesia and sedation
    o SQ:longestduration

Question 18

Commonly Used Drug Combinations

IV Recumbent Stun

Answer 18

• Inject IV a combination of:
o ★ Butorphanol 0.05 to 0.1 mg/kg (2.2 to 4.4 mg/100 lb)
o ★ Xylazine 0.025 to 0.05/kg (1.1 to 2.2 mg/100 lb)
★ Ketamine 0.3 to 0.5 mg/kg (14 to 23 mg/ 100 lb)
• Onset: 1 minute
• Duration: 15 minutes recumbency and analgesia
• Patients stand in approximately 20 to 25 minutes
• Use of local lidocaine block

Question 19

Commonly Used Drug Combinations

IM or SQ Recumbent Stun

Answer 19

• Provides longer duration with less analgesia
• Inject IM or SQ a combination of:
★ Butorphanol 0.025 mg/kg (1.1 mg/100 lb)
★ Xylazine 0.05/kg (2.3 mg/100 lb)
★ Ketamine 0.1 mg/kg (4.5 mg/100 lb)
• Onset: 5 minutes
• Duration: longer with SQ (45 min. recumbency) than IM
• Patients are generally standing in 75 to 90 minutes
• Use of lidocaine block

Question 20

Commonly Used Drug Combinations

IV Standing Stun

Answer 20

• Used to improve patient cooperation
• Inject IV a combination of:
★ Butorphanol 0.02 to 0.1 mg/kg (0.9 to 4.5 mg/100 lb)
★ Xylazine 0.02 to 0.0275/kg ( 0.9 to 1.25 mg/100 lb)
★ Ketamine 0.05 to 0.1 mg/kg (2.3 to 4.5 mg/100 lb)
• 15 to 20 minutes to allow examinations, etc.

Question 21

Commonly Used Drug Combinations

IM or SQ Standing Stun

Answer 21

• Used for standing procedures in cattle, i.e., cesarean or laparotomy
• Inject IM or SQ a combination of:
★ Butorphanol 0.01 mg/kg (0.45 mg/100 lb)
★ Xylazine 0.02 mg/kg (0.9 mg/100 lb)
★ Ketamine 0.04 mg/kg (1.8 mg/100 lb)