BCSE Surgery

Food Animal Surgery and Ophthalmic Surgery Basics – BCSE Study Guide

📅 March 28, 2026 ⏱ 30 min read

This comprehensive study guide covers two essential areas within BCSE Domain 6 (Surgery): food animal surgical procedures and basic ophthalmic surgery.

Overview and Clinical Importance

This comprehensive study guide covers two essential areas within BCSE Domain 6 (Surgery): food animal surgical procedures and basic ophthalmic surgery. Food animal surgery represents a critical component of mixed practice veterinary medicine, encompassing life-saving procedures such as cesarean sections, abomasal surgery, and dehorning. Understanding these procedures requires integration of anatomy, physiology, and surgical principles.

Ophthalmic surgery basics are essential for all veterinarians, as eye conditions requiring surgical intervention are common across species. Mastery of procedures such as enucleation, entropion and ectropion repair, and third eyelid gland repositioning prepares the entry-level veterinarian for both emergency and elective cases.

High-YieldDomain 6 (Surgery) comprises 22-25 questions on the BCSE (approximately 11% of scored questions). Food animal surgery questions frequently test cesarean section approaches, abomasal displacement surgical techniques, and appropriate dehorning methods. Ophthalmic questions often focus on indications for enucleation and the distinction between entropion and ectropion.

Approach	Advantages	Disadvantages
Standing Left Paralumbar (MOST COMMON)	Rumen prevents visceral prolapse. Cow remains standing. Minimal assistance needed. Familiar approach for most practitioners.	Difficulty if calf in right horn. Limited access for emphysematous fetus. Requires cow able to stand throughout procedure.
Standing Left Oblique	Follows uterine contour. Better exteriorization. Suitable for smaller surgeons. Good for large fetuses.	Larger incision. More difficult closure due to muscle tension. Greater risk of herniation.
Standing Right Paralumbar	Better access if calf in right horn. Can visualize other viscera.	Intestines may prolapse into incision. More contamination risk. Requires more vigilance.
Ventral Midline (Recumbent)	Direct access to uterus. Good for bilateral pregnancies. Easier uterine exteriorization.	Requires recumbency and more assistance. Higher anesthetic risk. Risk of rumen regurgitation.
Ventrolateral (Recumbent)	Best for emphysematous fetus. Excellent exteriorization. Avoids well-vascularized flank muscles.	Requires sedation/recumbency. More prone to infection. Risk of herniation and evisceration.

PART ONE: Food Animal Surgery

Bovine Cesarean Section

Cesarean section (C-section) is the extraction of the fetus through surgical incisions in the abdominal wall and uterus. This is one of the most commonly performed emergency surgeries in food animal practice and is indicated when vaginal delivery is impossible or would endanger the cow or calf.

MEMORY AID - "LEFT is BEST": L = Left flank is standard approach. E = Easier because the rumen blocks intestines. F = Favored for standing procedures. T = Technique allows uterine exteriorization. Remember: The RUMEN on the LEFT keeps EVERYTHING ELSE inside!

Indications for Cesarean Section

Fetopelvic disproportion (oversized calf, small pelvic canal)
Incomplete cervical dilation
Uterine torsion (especially greater than 270 degrees)
Uncorrectable fetal malpresentation, position, or posture
Fetal monsters or developmental abnormalities
Rupture of prepubic tendon or abdominal musculature
Pelvic fractures or canal obstruction
Elective: breed predisposition (Belgian Blue), embryo transfer calves, history of dystocia

[Include Image: Figure 1. Bovine paralumbar fossa anatomy showing landmarks for left flank cesarean section approach. Source: University of Minnesota Open Textbook - https://open.lib.umn.edu/largeanimalsurgery/chapter/how-to-left-flank-csection/]

Surgical Approaches Comparison

There are eight available surgical approaches for bovine cesarean section. Selection depends on the type of dystocia, cow condition, environmental conditions, availability of assistance, and surgeon preference.

High-YieldAVOID xylazine sedation BEFORE uterine closure! Xylazine causes direct myotonic effects on the uterus, making it friable and increasing the risk of tears during suturing. If sedation is necessary, administer AFTER uterine closure is complete.

Anesthesia for Standing Cesarean Section

Local anesthesia is standard for standing procedures. The most common techniques include:

Inverted L Block: Local anesthetic deposited in an inverted L pattern cranial and dorsal to the incision site. Quick to perform, effective, and does not interfere with standing position.
Proximal Paravertebral Block: Blocks T13, L1, and L2 spinal nerves proximal to transverse processes. Provides excellent analgesia with smaller volumes.
Distal Paravertebral Block: Blocks same nerves distal to transverse processes. Easier landmarks but requires larger volumes.
Line Block: Infiltration directly along incision line. Simple but may interfere with tissue handling. Generally not preferred for flank laparotomy.

MEMORY AID - Paravertebral Nerve Blocks "TLL = T13, L1, L2": Think "TaLL blocks" for the three nerves needed: T13, L1, L2. These provide sensation to the entire paralumbar fossa!

Surgical Procedure: Standing Left Flank Approach

Preparation: Restrain cow in chute or against wall. Clip and prep paralumbar fossa. Administer preoperative NSAIDs (flunixin meglumine 1.1-2.2 mg/kg IV) and antibiotics (procaine penicillin 22,000 IU/kg IM).
Incision: Make 35-40 cm vertical or oblique incision in center of paralumbar fossa, starting approximately 10 cm ventral to transverse processes.
Muscle Layer Dissection: Incise external abdominal oblique sharply. Bluntly dissect internal abdominal oblique along muscle fibers. Bluntly dissect transversus abdominis vertically. Tent and incise peritoneum.
Uterine Manipulation: Reach under viscera and identify uterus. Grasp fetal limb (usually hindlimb via hock) and bring non-pregnant horn containing limbs to incision.
Hysterotomy: Exteriorize portion of uterus containing fetal limb. Incise uterus over greater curvature avoiding placentomes and major vessels. Extract calf.
Uterine Closure: Close with double-layer inverting pattern (Utrecht or Cushing over Connell) using absorbable suture (chromic gut or polyglactin 910, size 2).
Abdominal Closure: Close in 3 layers: (1) peritoneum with transversus, (2) internal and external obliques together, (3) skin with non-absorbable suture (size 2-3).

Postoperative Care and Complications

Continue NSAIDs for 3 days. Monitor for incisional infection, which can be managed by removing distal sutures for drainage. Almost all cattle will develop retained placentas, which are managed with oxytocin (20-40 IU IM) and time (less critical than in horses). Watch for dehydration and mastitis.

High-YieldPrognosis for bovine C-section is generally GOOD. Survival rates are 81-99%. Future fertility is maintained in 84-100% of cows if the uterus was healthy at time of surgery. Decision to perform C-section vs. fetotomy depends on: calf viability, pelvic space, cervical dilation, and cow value.

Abomasal Surgery

Displaced abomasum (DA) is one of the most common surgical conditions in dairy cattle, primarily affecting high-producing cows in the first month postpartum. The abomasum can displace to the left (LDA), right (RDA), or rotate while displaced to create an abomasal volvulus (AV).

Pathophysiology

The abomasum is suspended loosely by the greater and lesser omentum, allowing movement from its normal ventral position. Key contributing factors include:

Abomasal hypomotility: Associated with hypocalcemia, hypokalemia, endotoxemia from concurrent disease (mastitis, metritis)
Increased gas production: Altered fermentation due to dietary changes (high concentrate, low fiber)
Postpartum changes: Decreased rumen fill after parturition creates space for abomasal displacement
Decreased fiber mat: Modern dairy rations with finely ground feed reduce the thick rumen mat that normally stabilizes visceral position

MEMORY AID - "5 Cs of DA Risk Factors": Calving (postpartum period), Concentrate (high grain diets), Calcium low (hypocalcemia), Concurrent disease (mastitis, metritis), Cow age (older cows at higher risk)

Diagnosis

The hallmark diagnostic finding is a characteristic "ping" on simultaneous auscultation and percussion:

LDA: Ping over left paralumbar fossa, especially last 3-4 ribs
RDA/AV: Ping over right paralumbar fossa, extending from last rib caudally
Clinical signs: anorexia, decreased milk production, ketosis. AV cases show rapid deterioration with tachycardia, dehydration, and colic signs.

[Include Image: Figure 2. Anatomical diagram showing position of abomasum in LDA vs. RDA. Source: Merck Veterinary Manual (open access) - https://www.merckvetmanual.com/digestive-system/diseases-of-the-abomasum/left-or-right-displaced-abomasum-and-abomasal-volvulus-in-cattle]

Surgical Techniques for LDA Correction

MEMORY AID - "H-O-U-R" for LDA Surgery Selection: H = Hannover (right flank omentopexy - most common field technique). O = Omentopexy uses omentum for fixation. U = Utrecht (left flank with toggle). R = Right paramedian (recumbent, most secure). Remember: Roll and Toggle = Rarely Recommended!

RDA and Abomasal Volvulus

RDA and abomasal volvulus (AV) are surgical emergencies. Unlike LDA, medical management is not appropriate due to the high risk of volvulus progression and rapid clinical deterioration.

Surgery: Right paralumbar fossa omentopexy is the treatment of choice
Critical: Time from onset to surgery is crucial for success. Administer antioxidative drugs (vitamin C, vitamin E) before surgery to limit reperfusion injury
Prognosis: Poorer than LDA, especially with prolonged volvulus. Abomasal atony postoperatively is common

High-YieldLDA can be treated medically early in course, but recurrence is very likely. SURGICAL CORRECTION has higher success rates than rolling alone. RDA/AV ALWAYS requires PROMPT SURGERY due to risk of volvulus and rapid deterioration!

Dehorning and Disbudding

Dehorning and disbudding are routine procedures in cattle and goats performed to reduce injury to animals and handlers. Disbudding destroys horn-producing cells before horn attachment to the skull, while dehorning removes established horns that are fused to the frontal bone.

MEMORY AID - "Dis-BUD = Before-Underneath-Develops": Disbudding is done BEFORE the horn bud attaches UNDERNEATH the skull (frontal bone) and DEVELOPS into a true horn with sinus communication. Once the horn connects to the sinus, you are DEHORNING!

Methods Comparison

[Include Image: Figure 3. Cornual nerve block anatomy in cattle showing injection sites. Source: University of Minnesota Open Textbook - https://open.lib.umn.edu/largeanimalsurgery/chapter/how-to-cosmetic-dehorning/]

Analgesia for Dehorning

Local anesthesia and systemic analgesia are recommended for all dehorning and disbudding procedures:

Cornual Nerve Block (Cattle): Palpate temporal ridge. Inject 5-10 mL lidocaine below the ridge, halfway between lateral canthus of eye and base of horn. Additional subcutaneous infiltration caudal and lateral to horn bud ensures complete block.
Goats: Block BOTH cornual AND infratrochlear nerves due to more extensive innervation. A ring block around the horn can supplement. Horn scent glands should also be removed in bucks.
NSAIDs: Meloxicam or flunixin meglumine administered pre- and post-procedure provides detectable analgesia and improves weight gain. Meloxicam can be given in milk prior to procedure for easy administration in calves.

MEMORY AID - "COWS have CORNUAL, GOATS get TWO": In CATTLE, the CORNUAL nerve alone provides adequate block. In GOATS, you need TWO nerves blocked (cornual AND infratrochlear) because goat horn buds are innervated differently!

Species Considerations

Goats vs. Cattle: Goat kids are NOT small calves! Key differences:

Goat skulls are thinner and softer - Barnes dehorners should NOT be used (risk of skull fracture)
Goat horn buds are closer to the brain - higher risk of thermal meningitis with cautery disbudding
General anesthesia is recommended for surgical dehorning in adult goats
Polled gene in goats was historically linked to hermaphrodism, though fertile polled goats have been bred

High-YieldCAUTERY disbudding produces a SMALLER cortisol response than AMPUTATION dehorning, suggesting it causes less pain. The earlier dehorning is performed, the less stress on the animal. Best welfare practice: disbud as EARLY as possible (when horn bud is palpable), use LOCAL ANESTHESIA, and provide NSAIDs.

Technique	Description	Advantages	Disadvantages
Right Flank Omentopexy (Hannover Technique)	Standing right flank approach. Deflate abomasum, pull to right side, pexy omentum to right flank incision.	Can visualize other viscera. Standing procedure. Good success rate (86-90%).	Cannot visualize displaced abomasum directly. Omentum may be friable. Not for adhesions or peritonitis.
Left Flank Abomasopexy (Utrecht Method)	Left flank laparotomy. Deflate abomasum, pexy directly to right ventral body wall through toggle suture.	Direct visualization of LDA. Can assess adhesions.	Cannot examine right side. Toggle technique requires skill.
Right Paramedian Abomasopexy	Cow in dorsal recumbency. Ventral incision right of midline. Direct pexy of abomasum to body wall.	Most secure fixation. Abomasum in anatomic position.	Requires recumbency. Risk of regurgitation and bloat. More difficult recovery.
Roll and Toggle (Closed/Percutaneous)	Cast cow on right side, roll to dorsal recumbency. Insert toggle through ventral body wall into abomasum.	No surgical incision. Fast. Low cost.	Very high recurrence rate (greater than 90%). Risk of wrong organ fixation. Not recommended.
Laparoscopic Abomasopexy (One or Two-Step)	Laparoscopic visualization and toggle placement under direct vision.	Minimally invasive. Faster post-op recovery. Direct visualization.	Expensive equipment. Requires specialized training. Not practical for field settings.

PART TWO: Ophthalmic Surgery Basics

Enucleation

Enucleation is the surgical removal of the globe, nictitating membrane, orbital glands, and eyelid margins. Exenteration additionally removes all orbital contents and is indicated for orbital neoplasia or extensive infection.

MEMORY AID - "E-nucleation vs. EX-enteration": E-nucleation removes the E (Eye/globe). EX-enteration = EXtra removal (takes EVERYTHING including orbital contents). Think: EX = EXtreme/EXtensive!

Indications for Enucleation

End-stage glaucoma unresponsive to medical management (painful, blind eye)
Severe uveitis or endophthalmitis unresponsive to treatment
Perforated corneal ulcer with irreparable damage
Severe ocular trauma (proptosis with extraocular muscle avulsion)
Intraocular neoplasia
Unresponsive painful dry eye with corneal scarring (when owner cannot pursue other treatment)

Surgical Techniques

[Include Image: Figure 4. Comparison of transconjunctival vs. transpalpebral enucleation approaches. Source: Clinicians Brief (open access) - https://www.cliniciansbrief.com/article/transpalpebral-enucleation-cats-dogs]

MEMORY AID - "TRANS-pal-PE-bral for INFECTED Eyes": Think "Trans-PAL-PE-bral = Pus And Lesions = Preferred for Encased removal." Close the eyelids first to ENCAPSULATE the infected contents, then remove everything as one unit to prevent spreading infection to the orbit!

Key Surgical Considerations

Surgical Prep: Use dilute povidone-iodine SOLUTION (1:50), NOT scrub. Detergent-based scrubs cause severe corneal damage if accidentally applied to healthy eye
Oculocardiac Reflex: Traction on globe or extraocular muscles can cause sudden bradycardia and hypotension. Stop manipulation and administer IV anticholinergic (atropine, glycopyrrolate) if needed
Complete Removal: Remove ALL conjunctival tissue and nictitating membrane with glands to prevent postoperative mucocele formation
Cosmesis: Orbital prosthesis can be placed to prevent cosmetic depression, but carries 5-10% infection risk. Many owners prefer simple enucleation due to less postoperative care.

Entropion and Ectropion

Entropion is the inward rolling of the eyelid margin, causing eyelashes and hair to contact and irritate the cornea. Ectropion is the outward rolling (eversion) of the eyelid, leading to conjunctival exposure and chronic irritation.

MEMORY AID - "EN-tro vs. EC-tro": EN-tropion = lid turns IN (EN = IN). EC-tropion = lid turns out, causing EXposure (EC sounds like EX). Both start with "E" for Eyelid problem!

Entropion

Clinical Signs: Squinting (blepharospasm), excessive tearing, mucoid discharge, photophobia, rubbing at eyes. Corneal ulceration may develop from chronic irritation.

Predisposed Breeds: Chinese Shar-Pei, Chow Chow, English Bulldog, Labrador Retriever, Golden Retriever, Rottweiler, Great Dane, St. Bernard, Pug, Cocker Spaniel. Breeds with heavy facial folds and specific skull conformation are at highest risk.

Types: (1) Primary/developmental - genetic, often seen before 1 year. (2) Secondary/acquired - from scarring, infection, chronic pain causing spasm, or nerve damage. (3) Spastic - temporary, due to painful corneal disease.

[Include Image: Figure 5. Entropion in a dog showing inward rolling of lower eyelid with corneal contact. Source: Veterinary Partner VIN (open access) - https://veterinarypartner.vin.com/doc/?id=4952708]

Surgical Correction of Entropion

Lid Tacking (Temporary): For young puppies (less than 6 months). Temporary sutures or staples roll eyelid outward while puppy grows. Used because head conformation may change with maturity. Very well tolerated; sutures maintained until condition resolves or permanent correction needed.
Blepharoplasty (Permanent): Elliptical excision of skin and orbicularis muscle below the affected eyelid (Hotz-Celsus procedure). Suturing pulls lid into normal position. Amount of tissue removed determined by awake examination. Overcorrection causes ectropion; undercorrection requires revision.

Ectropion

Clinical Signs: Visible drooping of lower eyelid, chronic conjunctival exposure (red, inflamed conjunctiva), excessive tearing, chronic keratitis from exposure.

Predisposed Breeds: Basset Hound, Bloodhound, Cocker Spaniel, St. Bernard, Great Dane. Often a breed characteristic ("droopy eye" appearance).

Surgical Correction: Indicated only if causing clinical problems. V-Y plasty or wedge resection shortens the eyelid. Some breeds have combined entropion/ectropion ("diamond eye") requiring complex repair with eyelid shortening and eversion.

High-YieldALWAYS perform a "no-touch" evaluation FIRST (observe lid position without manipulation), then evaluate AFTER topical anesthetic. The anesthetic removes the SPASTIC component, revealing the ANATOMICAL defect that requires surgical correction. Overcorrection of entropion causes ectropion!

Third Eyelid Gland Prolapse (Cherry Eye)

Cherry eye is the prolapse of the third eyelid (nictitating membrane) gland, appearing as a red, swollen mass at the medial canthus. This occurs due to hereditary weakness in the gland's normal fibrous attachments.

Clinical Significance

The third eyelid gland contributes 30-50% of total tear production. Removal (which was historically performed) strongly predisposes to development of keratoconjunctivitis sicca (KCS/dry eye). This is especially important because many breeds prone to cherry eye (Bulldogs, Cocker Spaniels) are also predisposed to KCS.

Predisposed Breeds: English Bulldog, French Bulldog, Cocker Spaniel, Lhasa Apso, Shih Tzu, Beagle, Boston Terrier, Pug, Bloodhound, brachycephalic breeds in general.

[Include Image: Figure 6. Cherry eye (third eyelid gland prolapse) in a dog showing characteristic red mass at medial canthus. Source: Veterinary Vision Animal Eye Specialists (open access) - https://www.veterinaryvision.com/learn-about-entropion-and-cherry-eye]

Surgical Treatment

Treatment of choice is surgical REPOSITIONING and FIXATION of the gland - NOT REMOVAL!

Pocket Technique (Morgan): Create a pocket in conjunctiva over the prolapsed gland, reposition gland into pocket, close with absorbable suture.
Anchoring Technique: Suture gland directly to orbital rim periosteum or ventral rectus muscle insertion.
Recurrence: May occur in 5-20% of cases and may require revision surgery.

MEMORY AID - "REPLACE, Don't REMOVE the Cherry": The third eyelid gland makes 1/3 of tears. Remove it = Remove 1/3 of tears = Risk of DRY EYE! Always REPLACE (reposition) the gland, never remove it!

High-YieldCherry eye should be corrected PROMPTLY to minimize damage to the gland. Prolonged exposure causes inflammation and fibrosis, which may permanently reduce tear production even after repositioning. NEVER recommend gland removal - this is outdated practice!