Small Animal Surgical Procedures – BCSE Study Guide

Overview and Clinical Importance

Small animal surgical procedures represent a core competency for every veterinarian. The BCSE examination tests your understanding of surgical principles, technique selection, and complication recognition across the most commonly performed procedures in dogs and cats. This domain accounts for 22-25 questions, making it one of the highest-yield areas for examination success.

Understanding surgical anatomy, proper tissue handling, instrument selection, and suture material choices is essential. Equally important is recognizing when surgery is indicated, what complications may arise, and how to manage the postoperative patient. The BCSE emphasizes clinical decision-making alongside technical knowledge.

Ovariohysterectomy (OVH)

Indications and Preoperative Considerations

Ovariohysterectomy (spay) is the surgical removal of both ovaries and the uterus. It is one of the most commonly performed procedures in small animal practice. Indications include elective sterilization, pyometra, ovarian/uterine neoplasia, dystocia, uterine torsion, and prevention of mammary neoplasia.

MEMORY AID - "SPAY Benefits" Mnemonic: Sterilization, Pyometra prevention, Avoid mammary tumors (if before first estrus = 200x less likely), Yield behavioral benefits (no estrus behavior).

Surgical Anatomy

Key structures to identify include: Ovaries (located caudal to kidneys within the ovarian bursa), suspensory ligament (runs from ovary to transversalis fascia medial to last rib), proper ligament (connects ovary to uterine horn), broad ligament (mesovarium, mesosalpinx, mesometrium), and uterine body (located between bladder and colon).

MEMORY AID - Ovarian Blood Supply: "Right to Cava, Left to Renal" - The RIGHT ovarian vein drains directly into the vena CAVA, while the LEFT ovarian vein drains into the LEFT RENAL vein. Both ovarian arteries arise directly from the aorta caudal to the renal arteries.

[Include Image: Figure 1. Canine Female Reproductive Tract Anatomy - showing ovaries, uterine horns, uterine body, and associated ligaments]

Surgical Technique - Canine OVH

MEMORY AID - Three-Clamp Technique: "2 Stay, 1 Go" - Place TWO clamps on the patient side (these STAY to mark where ligatures go), ONE clamp on the ovary side (this GOES with the tissue you remove). Ligate proximal to the two staying clamps, transect between them and the removed clamp.

Species Differences: Canine vs. Feline OVH

MEMORY AID - OVH vs OVE: OVH (OvarioHysterectomy) removes BOTH ovaries AND uterus. OVE (OvariEctomy) removes ovaries ONLY. Evidence shows NO difference in long-term outcomes including pyometra risk (hormone-dependent). OVE is shorter surgery, preferred in Europe. OVH remains standard in US/Canada.

OVH Complications

[Include Image: Figure 2. Three-clamp technique for ovarian pedicle ligation showing clamp placement and ligature positions]

Orchiectomy (Castration)

Indications and Surgical Anatomy

Orchiectomy involves surgical removal of both testicles. Indications include population control, behavioral modification (reducing roaming, territorial marking, intermale aggression), treatment of testicular neoplasia, and prevention/treatment of prostatic disease (benign prostatic hyperplasia, prostatitis).

Key anatomy: The spermatic cord contains the ductus deferens, testicular artery and vein, lymphatics, and nerves surrounded by the vaginal tunic (parietal layer of the tunica vaginalis). The cremaster muscle covers the tunic. The testicle is anchored distally by the ligament of the tail of the epididymis.

MEMORY AID - Spermatic Cord Contents: "DALVN" - Ductus deferens, Artery (testicular), Lymphatics, Veins (pampiniform plexus), Nerves. All wrapped in the vaginal tunic like a "gift wrap" around the cord structures.

Surgical Approaches

Open vs. Closed Technique

MEMORY AID - Open vs Closed: "Open = Open the tunic, Opens the abdomen (communication)." Closed keeps everything closed - tunic intact, no peritoneal communication. Research shows closed has FEWER early complications, but open allows better VISUALIZATION.

[Include Image: Figure 3. Comparison of prescrotal vs scrotal approaches for canine orchiectomy showing incision locations]

Gastrointestinal Surgery

General Principles

GI surgery is classified as clean-contaminated due to entry into the GI lumen. Key principles include: preventing contamination through proper "packing off" with moist laparotomy sponges, complete abdominal exploration before any procedure, and changing gloves/instruments after GI closure before abdominal wall closure.

MEMORY AID - GI Surgery Principles "PILSS": Pack off (isolate with moist sponges), Inspect entire tract, Lavage abdomen with warm saline, Switch gloves/instruments, Submucosa is the holding layer.

Gastrotomy

Gastrotomy is an incision into the stomach, most commonly performed for foreign body retrieval. The stomach is exteriorized and stay sutures are placed to facilitate manipulation. The incision is made in a relatively avascular area midway between the greater and lesser curvature. Closure is typically single-layer simple appositional or inverting pattern with 3-0 monofilament absorbable suture.

MEMORY AID - Gastrotomy Location: "Meet in the Middle" - The gastrotomy incision is placed MIDWAY between the greater and lesser curvatures, avoiding the highly vascular areas. Think of the stomach as a "bean" - cut through the middle of the bean, not at its curved edges where blood vessels run.

Enterotomy

Enterotomy is an incision into the intestine, performed for foreign body removal or biopsy. Key points: make the incision on the antimesenteric border (opposite the mesenteric attachment), incision should be in healthy tissue aborad (downstream) to the obstruction. If a foreign body can be "milked" back to the stomach, perform gastrotomy instead (stomach heals more reliably than intestine).

MEMORY AID - Enterotomy Location: "ANTI-Mesenteric for Enterotomy" - The ANTI-mesenteric border has LESS blood supply, so it is safer to cut there. Also remember: incise ABORAD (downstream) to the obstruction because tissue orad (upstream) is stretched and compromised.

Enterotomy closure: Simple interrupted appositional pattern with 4-0 monofilament absorbable suture. The submucosa is the holding layer - it must be engaged in every suture. The mucosa tends to evert and may need to be trimmed. A serosal patch can be applied for added security.

Intestinal Resection and Anastomosis (R and A)

R and A is indicated when intestine is non-viable (necrosis from intussusception, volvulus, strangulation), perforated, or contains neoplasia. End-to-end anastomosis is the preferred technique.

MEMORY AID - Intestinal Viability "CPBB": Color (pink good, gray/black bad), Peristalsis (should see movement), Bleeding (viable tissue bleeds when cut), Beating pulse (palpable mesenteric vessels).

Linear Foreign Bodies

Linear foreign bodies (string, yarn, ribbon) are more common in cats. They anchor at the base of tongue or pylorus, causing intestinal plication (accordion-like bunching). The string can saw through the mesenteric border causing perforation. Management: Release the anchor point FIRST (check under tongue, perform gastrotomy), then multiple enterotomies may be needed to remove the entire length. NEVER pull on a linear foreign body.

[Include Image: Figure 4. Intestinal plication from linear foreign body showing characteristic bunching of intestine on mesenteric border]

Urinary Tract Surgery

Cystotomy

Cystotomy is an incision into the urinary bladder. Indications include urolithiasis (stone removal), bladder biopsy, mass removal, and repair of traumatic bladder rupture. The incision is made on the ventral or dorsal surface of the bladder body, avoiding the trigone area (where ureters enter).

MEMORY AID - Cystotomy "Stay Away from the Trigone": The TRIGONE is the triangular area at the bladder neck where the two URETERS enter and the URETHRA exits. Incise on the bladder BODY (ventral or dorsal surface), NOT near the trigone, to avoid damaging the ureteral openings.

Cystotomy closure: Two-layer inverting pattern or single-layer appositional pattern with absorbable suture (3-0 to 4-0 monofilament). Some surgeons use a two-layer closure (first layer simple continuous through mucosa and submucosa, second layer Cushing or Lembert inverting pattern through serosa and muscularis). Water-tight seal is essential.

Perineal Urethrostomy (PU)

Perineal urethrostomy creates a permanent opening in the pelvic urethra, bypassing the narrow penile urethra. Indications include recurrent urethral obstruction (especially in male cats with feline lower urinary tract disease), urethral stricture, and severe urethral trauma.

MEMORY AID - Why PU Works in Cats: The feline penile urethra is the NARROWEST part - obstructions occur here. The pelvic urethra is 3-4x WIDER. PU bypasses the narrow section entirely by creating a new opening at the wider pelvic urethra. Think: "Bypass the Bottleneck."

Suture Selection for Small Animal Surgery

MEMORY AID - Suture Size: "The SMALLER the organ, the SMALLER the suture." Intestine (small lumen) = 4-0. Stomach (larger) = 3-0. Linea alba (strong tissue) = 2-0 to 3-0. Think of suture size like wire gauge - higher numbers are thinner/finer.