A & A Chp 11: Anesthesia of Ruminants, Camelids & Swine

What are three major anesthetic risks associated with general anesthesia in ruminants, and why are these patients particularly susceptible to them?

Produces a large amount of saliva> at risk of aspiration

Regurgitation/ Regurgtis

Fermentation> Bloat

Why can local anesthesia, with or without sedation, be preferred over general anesthesia when performing certain procedures in adult cattle?

Ability to Perform Standing Surgery, Safety for Veterinarians and Handlers, Simplicity and Cost-Effectiveness and Preservation of Appetite and Post-Procedural Pain Relief

Why is an anticholinergic not considered an essential component of every ruminant anesthetic protocol? Explain your answer.

Anticholinergic drugs cause saliva to become thick and ropy. These thicker strands of saliva are more easily aspirated, which can cause airway obstruction.

What is the purpose of the "double drip" anesthetic technique, and which two drugs are commonly combined to produce it?

Induction and short-term maintenance of general anesthesia in ruminants and camelids, Ketamine and Guaifenesin

You are preparing an adult cow for general anesthesia. Identify two important preoperative considerations that help reduce the risk of complications during anesthesia.

Fasting (Feed and Water Deprivation): Adult cattle should be fasted of solid food for 18 to 24 hours and water withheld for 12 to 18 hours

Describe the difference between the intubation techniques used in adult cattle versus small ruminants and calves.

Over all size, oral anatomy, and whether the technique is blind or visualized adult cattle (Blind Technique)

Animal mouth speculum or gag is inserted to keep the jaw open. The anesthetist inserts their non-dominant hand directly into the oral cavity and up into the laryngeal area, palpating the epiglottis

Small ruminants and calves (Visualized Technique)

A laryngoscope used to visualize the larynx, The tongue is often gently pulled forward using a gauze sponge. A narrow stylette that protrudes beyond the end of the endotracheal tube is passed into the airway first to safely navigate the larynx, and the ET tube is then slid over it.

Why is proper head positioning important when a ruminant is under general anesthesia? Specifically, where should the mouth be positioned in relation to the pharynx, and what complications does this help prevent?

Proper head positioning is important when a ruminant is under anesthesia because all ruminants should be positioned for surgery with the mouth lower than the pharynx to allow drainage of saliva and any regurgitated material from the mouth, preventing buildup in pharynx, which could lead to aspiration during recovery following extubation

Why are ruminants placed in sternal recumbency during anesthetic recovery? What is the importance of leaving the endotracheal tube in place during this period?

Ruminants generally are content to lie and start a sternal recumbency following anesthesia the development of complications from anesthetic recovery is generally limited to the residual effects of bloat. The endotracheal tube puffs should be either kept inflated or harshly deflated to assist the removal of saliva and regurgitates from the laryngopharynx on extubation.

Why can venipuncture of the jugular vein or carotid artery be particularly concerning in camelids?

Due to their unique neck anatomy, thick skin, and lack of a protective muscular groove separating these two major vessels. If a hematoma forms in this tight anatomical space, it cannot expand outward and can instead compress the trachea, causing partial or complete airway obstruction

A veterinary technician accidentally administers medication into the carotid artery instead of the jugular vein. What potential complications can occur with inadvertent intra-arterial medication administration, and why is correct vessel identification important?

Immediate, life-threatening neurological reactions, severe tissue damage, and death. Because the carotid artery carries oxygenated blood directly to the brain without passing through the heart and lungs first. Correct vessel identification is important because the jugular vein and carotid artery sit directly next to each other in the neck without a separating muscle layer, making accidental arterial puncture common.

What is one common respiratory complication camelids may develop under general anesthesia, and how should they be positioned during recovery to help minimize this risk?

Nasal edema, mouth lower than the pharynx to allow drainage of saliva and any regurgitated material from the mouth

What is the recommended recovery position for an anesthetized camelid? Explain why the head and neck should be maintained in a neutral, elevated position.

Sternal recumbency for recovery, the head and neck should be held upright in a normal position to promote venous drainage of any upper airway congestion that may have developed during the procedure.

Why is the preoperative physical examination of a pig often limited compared with that of a dog or horse? What are two additional challenges this creates for the anesthesia team?

Noisey, sensitive to stress, physically difficult to restrain, and have thick subcutaneous tissue. Won’t be able to get preoperative blood work/vascular access and unrecognized cardiopulmonary disease and baselines unknown

Why are pigs generally more difficult to sedate than other domestic veterinary species? Identify a commonly used drug combination for heavy sedation or injectable anesthesia in pigs.

Skin is thick, don’t have readily accessible peripheral veins or arteries, drug combination: TKX- Telazol, Ketamine, Xylazine

Following sedation or induction, which peripheral vessel is commonly used for IV catheter placement in pigs? Why is it often easier to access at this point?

Aural vein and small increments, less stress and movement, Peripheral vasodilation, and easy to see

Identify three reasons why endotracheal intubation can be challenging in pigs.

Long snout and narrow oropharyngeal cavity, Thick tongue and elongated soft palate, Curved larynx and pharyngeal diverticulum

Why can oscillometric blood pressure monitoring be unreliable in pigs? What anatomical feature contributes to this problem?

Because soft tissue dampens arterial pulse oscillations and prevents even cuff compression. The primary anatomical features contributing to this problem are their short, thick, conical limbs and heavy accumulations of subcutaneous fat

What is porcine stress syndrome (PSS)? Identify at least three clinical signs or physical changes that may be observed in an affected pig.

Malignant hyperthermia, mutation in one genes that controls calcium metabolism in the muscle. Muscle rigidity, rapid raise in temp, hypercapnia, hyperkalemia, and death.

You are assisting with general anesthesia on an adult cow undergoing a surgical procedure. During anesthesia, you notice excessive saliva accumulating around the mouth and the patient's respiratory effort appears decreased.

• What two anesthetic complications should you be concerned about?

• What positioning consideration is important?

• Why is close respiratory monitoring necessary?

• Aspiration/airway obstruction, and Hypoventilation

• Head positioning is important

• To track early detection of hypoxemia and hypercapnia, and assessment of anesthetic depth and bloat

You are assisting with anesthesia on a pig. The veterinarian is having difficulty obtaining a reliable blood pressure reading, and the patient is difficult to intubate.

Why are these two challenges common in pigs?

Noisey, sensitive to stress, physically difficult to restrain