ICVA - International Council for Veterinary Assessment Bovine Surgical Principles Questions and Answers 1 — Questions and Answers
Question 1: When performing a cornual nerve block for dehorning an adult cow, what is the primary anatomical landmark for injection?
- The facial tuberosity
- The temporal ridge, midway between the lateral canthus and the base of the horn (Correct answer)
- The supraorbital foramen
- The muscular process of the mandible
Correct answer: The temporal ridge, midway between the lateral canthus and the base of the horn
The cornual nerve, a branch of the zygomaticotemporal nerve, is blocked by injecting local anesthetic along the temporal ridge (frontal crest). The injection site is located approximately halfway between the lateral canthus of the eye and the base of the horn.
Question 2: A veterinarian is preparing for a standing left-flank laparotomy on a dairy cow. Which of the following regional anesthetic techniques provides the most complete and uniform desensitization of the entire flank, including the peritoneum and deep muscle layers?
- Inverted L block
- Line block
- Proximal paravertebral nerve block (Correct answer)
- Caudal epidural anesthesia
Correct answer: Proximal paravertebral nerve block
The proximal paravertebral nerve block targets the spinal nerves (T13, L1, L2) as they emerge from the intervertebral foramina. This technique blocks the nerves more proximally, resulting in a wide, uniform area of anesthesia and muscle relaxation that includes the skin, muscle layers, and peritoneum, which is ideal for a laparotomy. The Inverted L and line blocks do not reliably anesthetize the deeper layers, and a caudal epidural targets the perineal region, not the flank.
Question 3: During a rumenotomy to remove a foreign body, the surgeon must prevent contamination of the peritoneal cavity. Which of the following is a standard technique to achieve this?
- Continuously lavaging the abdomen with sterile saline throughout the procedure
- Administering a high dose of systemic antibiotics 30 minutes before the incision
- Securing the rumen to the skin incision with a continuous suture pattern or a rumen board/shroud before incising the rumen (Correct answer)
- Packing the abdomen with sterile laparotomy sponges soaked in povidone-iodine
Correct answer: Securing the rumen to the skin incision with a continuous suture pattern or a rumen board/shroud before incising the rumen
To prevent leakage of rumen contents into the sterile abdominal cavity, the rumen wall is exteriorized and secured to the skin edges before it is opened. This can be accomplished using a rumen board, a Weingarth frame, or by suturing the rumen to the skin, creating a seal that isolates the surgical field from the peritoneum. Lavaging the abdomen during the procedure would spread contamination, and while antibiotics are important, they do not physically prevent spillage.
Question 4: A 6-month-old calf undergoes surgical dehorning. Which of the following is the MOST common and immediate post-operative complication that requires careful monitoring?
- Hemorrhage from the cornual artery (Correct answer)
- Facial nerve paralysis
- Chronic sinusitis
- Wound infection and myiasis
Correct answer: Hemorrhage from the cornual artery
Uncontrolled bleeding from the cornual artery is the most immediate and life-threatening complication following surgical dehorning, especially in older calves. Calves should be observed closely for at least 30-60 minutes post-procedure, and methods for hemostasis like cautery or ligation should be readily available. While sinusitis and infection are potential complications, they typically occur later.
Question 5: A surgeon is performing an intravenous regional anesthesia (IVRA), or Bier block, to anesthetize the distal limb of a cow for a claw amputation. Which of the following steps is critical for the safety and efficacy of this procedure?
- Injecting the local anesthetic as rapidly as possible to ensure quick distribution
- Using a local anesthetic solution containing epinephrine to prolong the block
- Placing a tourniquet proximal to the intended surgical area and injecting the anesthetic into a distal vein (Correct answer)
- Removing the tourniquet immediately after injecting the full dose of anesthetic
Correct answer: Placing a tourniquet proximal to the intended surgical area and injecting the anesthetic into a distal vein
The principle of a Bier block is to isolate the limb's circulation with a tourniquet and then infuse a dilute local anesthetic into a distal vein. The tourniquet confines the anesthetic to the limb, allowing it to diffuse into the tissues and anesthetize the nerves. The tourniquet must remain inflated for a minimum period to prevent a toxic systemic bolus of the anesthetic. Anesthetic should be injected slowly, and epinephrine is contraindicated as it can cause severe vasoconstriction and tissue damage in a distal limb.
Question 6: When closing a left paralumbar fossa incision in a cow after a rumenotomy, which suture material characteristic is most desirable for closure of the abdominal muscle layers?
- Rapidly absorbable, multifilament
- Non-absorbable, monofilament
- Absorbable, monofilament with prolonged tensile strength (Correct answer)
- Natural, absorbable (e.g., chromic gut)
Correct answer: Absorbable, monofilament with prolonged tensile strength
The abdominal wall is a high-tension area that requires secure closure for proper healing. An absorbable monofilament suture with prolonged tensile strength (like polydioxanone or polyglyconate) is ideal. It resists contamination better than multifilament sutures, and its prolonged strength supports the incision during the critical healing period before it is eventually absorbed. Rapidly absorbable sutures may lose strength too quickly, and non-absorbable sutures are generally not necessary and can increase the risk of suture reactions or fistulas.
