Ruminant/Porcine Anesthesia

In general for Ruminants

• Performed less due to effectiveness of blocking techniques

  • Calm temperament allows for minimal sedation, if any

• Continuous production of saliva

• Rumen and forestomaches occupy 75% of abdominal cavity

  • Long periods of fasting needed

  • Makes ventilating on their own really difficult

Ruminant Preanesthetic Preparation

• Thorough history should be obtained

• Patient examination not always possible

• PCV/TP sufficient in healthy patients

• Fasting: 12-18 hours

• Have supplies ready

Supplies to have prepared for Ruminants

• ET-tube (must check length)

• Stylet, various types/sizes

• Cuff syringe

  • canstant rumen and saliva slow

• Eye-lube

• Something to secure tube - be sure it's secure so it doesn't slide down, unintentionally extubating during anesthesia

• Drugs

ET tubes for ruminants

Tube needs to go past larynx

Stylets for Ruminants

• Stylet is put past the arytenoids first, then ET tube is slid over to intubate

• Stylet needed due to limited view of arytenoids. Lots of soft tissue

Pre-Meds for ruminants - Preferred

• Xylazine

  • Very low doses! Highly sensitive

  • Created vocal effects from patient. They will often begin to "moo"

• Benzodiazepines

  • Less excitement seen, good sedation and muscle relaxant

• Butorphanol

• GG

Pre-Meds for ruminants not preferred

• Many different beliefs and combinations

  • Anticholinergics - controversial

  • Maybe slightly drier, but makes for difficult to deal with - ropey saliva when given

Induction for Ruminants

• A patent catheter is essential for general anesthesia of any size ruminant

• Aim is for a quick, safe induction with quick intubation

• All based on doctor preference

• Large patients may be placed in a chute or tilt table

• Head should be kept elevated perpendicular to the ground to reduce chances of aspiration (sternal positioning)

Induction for Smaller ruminants

• Propofol

• Ketamine/diazepam

Induction for Larger ruminants

• Usually GK (GG + 1gm ketamine) to effect after moderate sedation with pre-med

• Ketamine/diazepam may also be used

Intubation for Ruminants

• Smaller ruminants usually require a stylet to intubate

• Long, drooping soft palates and limited jaw opening may make intubation difficult

• Should always be done as quickly after induction as possible

• Larger ruminants need to be palpated to intubate efficiently

• Always remember a mouth speculum!

To intubate ruminants successfully

• You need to palpate

• To far back for the laryngoscope and too much soft tissue

Positioning and Monitoring

• Similar to equine

• Much higher BP and HR than equine patients

• Fluids 5-10 mL//kg/hr

Monitoring Ruminants

• Direct BP

• Monitor eyes (more like a dog)

• Keep well padded

• Pull bottom front limb forward and support upper limbs

Ruminants BP and HR

• Systolic greater than 180mmHg often

• MAP ideally above 80mmHg, but 60mmHg is minimum

• Pediatric ruminants have normal’s similar to dog

Ruminants normal BP

• Systolic = >180mmHg

• MAP = above 80mmHg but 60mmHg is minimum

Ruminants fluid rate

5-10ml/kg/hr

• often run slower to reduce pulmonary edema complications

Ruminant Recovery

• Usually a calm, sensible recovery

  • Keep in sternal recumbency with head supported laterally with spine

  • Extubate when beginning chewing/swallowing while keeping cuff partially inflated

    • Keeps eructated contents above cuff to be removed with ET tube

• Use caution and safety with larger patients

  • Prompt evacuation

• Remember cautions of reversals with camelids

  • Pulmonary edema dangers

General considerations for Porcine anesthesia

• Excitatory and loud patients. General anesthesia for the pet pig is usually required

  • Pig spa day

    • Clean folds, trim nails, clean ears

  • Urinary obstruction common

  • Foreign body

  • More popular pet, newer problems addressed

• Some procedures may be done with sedation and local blocking instead of general anesthesia

  • Uncomplicated c-section

  • Lower cost for production pigs

Difficulties is Porcine

• Restraint

• Few accessible arteries and veins

• Tracheal intubation is more challenging

• Malignant hyperthermia

• Difficult IM injections

Pigs restraint

• Chemical often needed

• Stress prevention

Pigs difficult IM injection

• Tough skin

• Very thick fat later 1.5" larger needle

• Cervical muscle ideally

Preanesthetic Prep for Porcine

• With hold feed for 12 hours, water for 6

• Have all drugs and supplies ready

  • Ideally remove from trailer soon after arrival to prevent hyperthermia

  • Face mask if necessary, multiple sizes

    • Sometime you need to be creative

• Prepare anesthetic record

Induction for porcine

• If you have an IV catheter:

  • IV ketamine/diazepam may be used

  • IV Propofol

• IM induction current preferred method

Porcine IM induction

• Small volume optimal for injection

• Luer-lock syringe often better

• May have longer recovery time than desired for form site use

  • Dependent on drug combination

• Time duration varies on what you reconstitute Telazol with

  • Xylazine

  • Butorphanol

  • Dexmeditomedine (may vomit)

• Can use lesser dose and add inhalant via mask

Porcine Intubation

• Limited view of larynx

  • Laryngoscope needed!

• Laryngospasm easily obtained

  • Minimal manipulation best

  • Can use lidocaine gel

• Larynx is long and mobile

• May have excess salivary secretion

  • Have suction available

• Use of stylet preferred

  • Used same as previously described for ruminants, but better results to twist or screw in ET tube rather than just push

  • Be gentle!

Porcine Monitoring

• Protect small swine from hypothermia

• Often limited devices work

• May be able to get direct blood pressure via ear artery

• Venous ear catheter good insurance for longer procedures and to give IV fluids

• Cephalic and saphenous veins may be accessible in pediatric pigs

Porcine Monitoring Devices

Often, you are limited by what works

• Count HR/RR

• ECG

• NIBP can work depending on patient legs

• SpO2 probe placed on tongue, toes, or thinner area (ears)

Porcine anesthesia recovery

• Nice calm recovery

• Similar to ruminants

• Keep sternal for easier ventilation

• Usually begin walking around after drugs have worn off

• Remove ET tube after swallowing if intubated