VETERINARY SURGERY - Complete Topic-Wise Notes

SECTION 1: ANAESTHESIA & SEDATION

1.1 Facial Nerve Block

• Relieve blepharospasm (eyelid spasm) to allow ocular examination
• Facilitate eye surgeries

• Auriculopalpebral nerve block (branch of facial nerve): The nerve is palpated as it crosses the zygomatic arch. 5-10 mL of lidocaine (2%) is injected subcutaneously along the zygomatic arch.
• This causes motor paralysis of the upper eyelid (ptosis) without affecting corneal sensation.
• Used in combination with a retrobulbar block for complete eye anesthesia.

1.2 Epidural Anaesthesia

1. Caudal (low) epidural - most common in cattle, horses, sheep
   • Site: between Co1-Co2 (first and second coccygeal vertebrae)
   • Used for: tail surgery, perineal surgery, dystocia, prolapse reduction, urethrostomy, rectal/vaginal examinations
   • Drug: 2% lidocaine, 1-2 mL/100 kg body weight
   • Animal remains standing
2. Lumbosacral epidural - used in small animals (dogs/cats)
   • Site: L7-S1 junction
   • Used for: hindlimb, perineal, urogenital surgeries
   • Drugs: lidocaine, bupivacaine, morphine, xylazine

1.3 Pudic (Pudendal) Nerve Block

• The pudendal nerve is blocked at the lesser sciatic foramen.
• Animal is cast in lateral recumbency.
• A needle is inserted per rectum, guided to the lesser sciatic notch, and 20-30 mL of 2% lidocaine is injected on each side.
• Results in penile protrusion within 10-15 minutes.

1.4 Shock

1. Compensated - body maintains BP via tachycardia, vasoconstriction; mucous membranes pale/pink, CRT < 2 sec
2. Decompensated - BP falls, pale/white mucous membranes, CRT > 2 sec, cold extremities, weak pulse
3. Terminal/Irreversible - organ failure, death imminent

• V - Ventilation (ensure airway & oxygen)
• I - Infusion (IV fluids - crystalloids first: LRS, NS at 90 mL/kg/hour in dogs; then colloids)
• P - Pump support (vasopressors: dopamine, dobutamine if needed)
• Treat underlying cause
• Corticosteroids in anaphylactic/septic shock (controversial)
• Monitor: HR, RR, BP, CRT, urine output, PCV/TP

1.5 Wild Animal Anaesthesia

• Inability to fast the animal beforehand
• Stress-induced capture myopathy risk
• Wide variation in drug sensitivities across species
• Need for remote delivery systems

• Minimize stress; plan thoroughly
• Use combination protocols for balanced anesthesia
• Have reversal agents ready

1.6 Dehydration

• Calculate deficit: % dehydration × body weight (kg) × 10 = mL needed
• Add maintenance (50 mL/kg/day) and ongoing losses
• Oral rehydration (ORS) for mild-moderate cases
• IV fluids (LRS, Normal Saline, Dextrose-saline) for severe cases
• Correct electrolyte imbalances (Na+, K+, Cl-, HCO3-)

1.7 Water Intoxication (Hypo-osmolar Overhydration)

• Calves given excessive hypotonic fluids
• Young animals with over-enthusiastic oral rehydration
• Post-surgery excessive IV 5% dextrose

• Stop water/hypotonic fluid administration
• Hypertonic saline (7.2% NaCl) IV slowly
• Furosemide (diuretic) to eliminate excess water
• Supportive care; anti-seizure medications (diazepam)

1.8 Anaesthetic Machine & Breathing System

1. Gas supply - O2 and N2O cylinders + pressure gauges
2. Pressure regulators - reduce cylinder pressure to working pressure
3. Flowmeters (Rotameters) - control gas flow rates
4. Vaporizer - delivers precise concentration of volatile anesthetic (isoflurane, sevoflurane, halothane)
5. Common gas outlet - connects to breathing circuit
6. Breathing circuit - delivers anesthetic gases to patient
7. CO2 absorber (soda lime) - absorbs exhaled CO2 in rebreathing systems
8. Rebreathing bag (reservoir bag) - provides manual ventilation capability
9. Pop-off valve (APL valve) - releases excess gas pressure

• Rebreathing (circle system): CO2 absorbed by soda lime; economical; suitable for large animals and longer procedures
• Non-rebreathing (Mapleson circuits - A, B, C, D, E, F): No CO2 absorber; fresh gas sweeps CO2 away; used in small patients (< 7 kg) and pediatric patients
• Bain circuit (co-axial Mapleson D): Common in small animals; fresh gas flows inside, expired gas flows outside

1.9 Paravertebral Nerve Block

1. Proximal (Farquharson) technique:
   • Needle inserted 4-5 cm lateral to dorsal midline at the tips of the lumbar transverse processes
   • Blocks nerve as it exits the intervertebral foramen
   • Produces a wide band of analgesia; may cause some weakness of back muscles
2. Distal (Cambridge/Hall) technique:
   • Nerves blocked distally at the ends of the transverse processes
   • Less muscle weakness
   • More technically demanding

1.10 Biomaterial & Stem Cell Therapy

• Suture materials - absorbable (catgut, PGA, PDS) and non-absorbable (nylon, polypropylene, stainless steel)
• Bone plates, screws, pins, wires - for fracture fixation
• Mesh implants - polypropylene mesh for hernia repair
• Bone substitutes - hydroxyapatite, tricalcium phosphate for bone defects
• Vascular grafts - PTFE, Dacron for vessel reconstruction

• Mesenchymal Stem Cells (MSCs) - from bone marrow, adipose tissue, umbilical cord blood
• Platelet-Rich Plasma (PRP) - concentrated growth factors

• Equine tendon and ligament injuries (superficial digital flexor tendon injuries)
• Osteoarthritis - intra-articular injection in horses and dogs
• Non-healing wounds
• Spinal cord injuries
• Bone defects

1.11 Chemical Immobilization of Wild Animals

• Remote injection systems (dart guns - CO2 rifle, pneumatic rifle)
• Blow pipes (short range)
• Pole syringes (captured/cage animals)

• Respiratory rate (most critical)
• Heart rate
• Body temperature (hyperthermia is common)
• SPO2 if possible
• Protect eyes (lubricant + cover)
• Position laterally; head elevated

1.12 Injectable Anaesthesia

• Dog: Acepromazine + Butorphanol + Atropine (premed) → Propofol IV induction → Isoflurane maintenance
• Horse: Xylazine IV → Ketamine + Diazepam IV induction → Isoflurane maintenance
• Cattle: Xylazine IM/IV alone (often sufficient for minor procedures)

1.13 Emergency Anaesthetic Monitoring

• A - Airway: Patent ET tube, no kinking
• B - Breathing: RR, tidal volume, capnography (EtCO2 - normal 35-45 mmHg)
• C - Circulation: HR, rhythm (ECG), blood pressure (direct arterial or oscillometric), pulse quality
• D - Depth of anesthesia: Eye position, jaw tone, reflexes (palpebral, pedal), response to surgical stimulation
• E - Everything else: Temperature, SpO2 (pulse oximetry - target >95%), urine output

• Respiratory arrest: IPPV (intermittent positive pressure ventilation), doxapram IV
• Cardiac arrest: CPR (chest compressions + IPPV), epinephrine, atropine
• Hypotension: IV fluid bolus, dopamine, dobutamine
• Hypothermia: External warming
• Malignant hyperthermia (pigs): Dantrolene IV, cooling, oxygen

SECTION 2: ABDOMINAL SURGERY

2.1 Surgical Approaches to the Abdomen

• Good exposure of the target organ
• Minimize trauma to surrounding structures
• Allow for adequate closure

1. Ventral midline laparotomy - most common; along linea alba; good exposure to all abdominal organs; simple closure
2. Paramedian incision - parallel to midline; through rectus abdominis
3. Flank incision - for kidney, adrenal, unilateral ovariectomy

1. Right paralumbar fossa (right flank) - for abomasum surgery (Right Displaced Abomasum), liver, right kidney
2. Left paralumbar fossa (left flank) - for rumenotomy, LDA, left kidney
3. Ventral midline - for caesarean section (in dorsal recumbency), umbilical hernia repair
4. Right paramedian - for abomasopexy

1. Ventral midline - for most colic surgeries (jejunum, large colon, cecum)
2. Right flank - for right colon and cecum
3. Left flank - for left colon, nephrectomy

SECTION 3: HERNIAS

3.1 Hernia - General

1. Hernial ring (opening/defect) - the opening through which contents protrude
2. Hernial sac - the peritoneal pouch covering the herniated contents
3. Hernial contents - omentum, intestine, bladder, uterus, etc.

• Reducible: Contents can be returned manually; no adhesions
• Irreducible (Incarcerated): Contents cannot be returned; adhesions present
• Strangulated: Blood supply cut off; ischemia/necrosis; surgical emergency

• Conservative: Taxis (manual reduction) + bandaging in young animals (umbilical hernia in foals/calves)
• Surgical: Herniorrhaphy - reduction of contents + closure of hernial ring
  • Simple closure (sutures)
  • Mesh repair for large defects

3.2 Umbilical Hernia

• Failure of umbilical ring to close after birth (congenital)
• May have hereditary predisposition (especially in Hereford cattle, Berkshire pigs)
• Infection/abscessation of umbilicus can prevent normal closure

• Soft, reducible swelling at umbilicus
• Contents usually omentum ± small intestine
• Size varies from small (fingertip) to large (football-sized)

• Small hernias in neonates: Conservative - clamp technique (rubber ring/plastic clamp applied to hernial sac), or truss/bandage
• Surgical (herniorrhaphy):
  1. Animal in dorsal recumbency under general anesthesia
  2. Elliptical skin incision around hernia
  3. Hernial sac dissected, contents reduced, sac excised
  4. Hernial ring closed with interrupted or mattress sutures (non-absorbable, e.g., PDS or nylon)
  5. Subcutaneous tissues and skin closed routinely

3.3 Ventral Hernia

• Traumatic (kick, fence injury, bull goring)
• Post-surgical dehiscence
• Pregnancy-related in mares (ventral body wall rupture)

• Surgical repair - direct apposition if edges healthy
• Mesh implant (polypropylene mesh) for large defects
• Prognosis guarded for very large defects in horses; conservative management (support bandage) sometimes preferred

3.4 Inguinal Hernia

• Indirect inguinal hernia: Contents pass through the vaginal ring into the vaginal tunic (congenital; more common); seen in horses, pigs, dogs
• Direct inguinal hernia: Contents pass directly through the abdominal wall medial to inguinal ring (rare in animals)

• Horses: Most common in colts/stallions; loop of small intestine enters vaginal ring; can cause colic and strangulation - surgical emergency
• Pigs: Common; hereditary in some breeds
• Dogs: Predisposed breeds include Basset Hound, Pekingese; common in intact males

• Horses: Manual reduction under anesthesia; if strangulated - laparotomy + herniotomy; orchidectomy often performed simultaneously (closes vaginal ring)
• Dogs: Herniorrhaphy through inguinal approach; castration recommended in males to prevent recurrence

3.5 Diaphragmatic Hernia

• Traumatic - most common; road traffic accidents (cats, dogs); increased abdominal pressure ruptures diaphragm
• Congenital - peritoneopericardial diaphragmatic hernia (PPDH) - most common congenital type; seen in dogs/cats; abdominal organs enter pericardial sac

• Respiratory distress (dyspnea, tachypnea, cyanosis)
• Muffled heart/lung sounds
• Gastrointestinal signs (vomiting, anorexia)
• Absence of normal gut sounds in abdomen
• May be asymptomatic for years (especially PPDH)

• Surgical repair under general anesthesia (always intubate + IPPV)
• Approach: ventral midline laparotomy or right paracostal
• Abdominal organs returned to abdomen
• Diaphragm repaired with interrupted sutures (PDS)
• Thoracic cavity evacuated of air (chest drain or Heimlich valve)

3.6 Perineal Hernia

• Weakening of pelvic diaphragm muscles (coccygeus, levator ani)
• Hormonal influence of testosterone (atrophy of levator ani)
• Chronic straining (tenesmus) due to rectal/prostatic disease

• Unilateral or bilateral soft swelling beside the anus
• Tenesmus, constipation, perineal bulging when straining
• Dysuria if bladder is herniated (surgical emergency if bladder retroflexion occurs)

• Surgical herniorrhaphy - internal obturator muscle transposition technique most common
• Castration mandatory to remove hormonal influence and prevent recurrence
• Prognosis: 20-46% recurrence rate; bilateral repair recommended even if unilateral presentation

SECTION 4: LAMENESS

4.1 Lameness - General

• Grade 0: No lameness
• Grade 1: Difficult to observe; not consistently apparent
• Grade 2: Difficult to observe at walk; consistent at trot
• Grade 3: Consistently obvious at trot
• Grade 4: Obvious at walk
• Grade 5: Minimal weight bearing; refuses to move

1. History (onset, duration, worsening/improving factors)
2. Observation at rest (posture, stance, muscle symmetry)
3. Movement (walk, trot in straight line and circles, hard/soft surface)
4. Flexion tests
5. Hoof testers
6. Nerve/joint blocks (diagnostic analgesia)
7. Imaging (radiography, ultrasonography, MRI, scintigraphy)

4.2 Specific Lameness Conditions

Radial Paralysis

• Damage to radial nerve (most commonly from prolonged lateral recumbency - "down" animals, fractures of 1st rib or humerus)
• Results in inability to extend carpus/digits; "dropped elbow" appearance
• Treatment: Remove cause, NSAIDs, physiotherapy; nerve regeneration takes weeks-months

Bursitis

• Inflammation of a bursa (fluid-filled sac between tendons/bones)
• Capped elbow (Shoe boil): Inflammation of the olecranon bursa; cattle and horses; caused by trauma from hoof when lying down
• Capped hock: Inflammation of calcaneal bursa; cattle; from trauma
• Treatment: Rest, anti-inflammatory drugs, drainage, intralesional corticosteroids; surgical excision for chronic cases

Omarthritis (Shoulder joint arthritis)

• Inflammation of the shoulder (scapulohumeral) joint
• Causes: trauma, septic arthritis (especially in neonates), OCD (osteochondrosis dissecans)
• Signs: muscle atrophy of shoulder, swelling, pain on flexion/extension
• Treatment: Rest, NSAIDs, intra-articular corticosteroids/hyaluronic acid; arthroscopy for OCD

Hygroma

• False bursa (acquired) over a bony prominence due to repeated trauma
• Common sites: carpus (carpal hygroma), hock, elbow
• Fluid-filled, painless swelling
• Treatment: Drain, inject with corticosteroids; surgical excision for chronic cases; address underlying cause (hard flooring)

Carpitis

• Inflammation of carpal joints
• Horses: "Popped knee" from trauma, overwork
• Signs: Effusion, heat, pain over carpus
• Treatment: Rest, cold therapy, NSAIDs, bandaging; intra-articular injections

Sore Shin (Bucked Shins)

• Periostitis of the dorsal cannon bone (MC3) in young racehorses (Thoroughbreds)
• Caused by repetitive stress during early training
• Signs: Pain, heat, swelling on dorsal surface of cannon bone
• Treatment: Rest (3-6 months), NSAIDs, controlled return to exercise; stress fractures may require surgery

Wind Puffs (Wind Galls)

• Distension of fetlock joint capsule (articular windgall) or digital flexor tendon sheaths (tendinous windgall)
• Common in horses; often bilateral; usually not lame
• Articular windgalls: more significant clinically
• Treatment: Often cosmetic concern only; rest, cold therapy, support bandaging; intra-articular hyaluronic acid

Tendonitis

• Inflammation/degeneration of a tendon
• Superficial Digital Flexor Tendon (SDFT): Most common in horses; "bowed tendon"
• Caused by overloading/overstretching during fast work
• Signs: Acute - heat, swelling, pain, lameness; Chronic - firm, thickened tendon ("bowed" appearance)
• Ultrasound: shows core lesion, fiber disruption
• Treatment: Rest (6-18 months), cold therapy, controlled rehabilitation; stem cell therapy / PRP injection into lesion

Stringhalt

• Sudden, involuntary, exaggerated flexion of one or both hind limbs during movement
• Horse specific condition
• Causes:
  • Classic (Australian) stringhalt: pasture-associated; related to plant toxin (false dandelion - Hypochoeris radicata); bilateral
  • Idiopathic (unilateral): nerve damage, foot pain, trauma
• Treatment:
  • Remove from pasture (Australian type - spontaneous recovery in months)
  • Lateral digital extensor tenectomy (surgical; removes a portion of the lateral digital extensor tendon above the hock)
  • Phenytoin, mephenesin (limited benefit)

UFP (Upward Fixation of Patella)

• The medial patellar ligament hooks over the medial trochlear ridge of the femur, locking the stifle in extension
• Horses, cattle (especially young/thin animals)
• Signs: Limb locked in extension at stifle; dragging of toe; usually releases with forward movement with a "click"
• Treatment:
  • Exercise and body condition improvement (first line in mild cases)
  • Medial patellar ligament splitting/desmotomy (surgical - longitudinal cuts to weaken the ligament)
  • Counter-irritant injection into medial patellar ligament
  • Prognosis: good with surgical treatment

Gonitis (Stifle Joint Disease)

• Inflammation of the stifle (femorotibial + femoropatellar) joint
• Causes: trauma, septic arthritis, OCD, cruciate ligament rupture (dogs/cats), upward fixation of patella
• Signs: Effusion, pain on flexion, muscle atrophy (quadriceps)
• Treatment: Depends on cause; rest, NSAIDs, intra-articular injections; surgical correction of cruciate rupture (TPLO, TTA in dogs)

Chondromalacia

• Softening and degeneration of articular cartilage (articular cartilage malacia)
• Common in stifle (patella) in dogs; also seen in horses
• Causes: Abnormal stress, osteochondrosis, trauma
• Signs: Crepitus, pain on compression of patella, stifle effusion
• Treatment: Conservative (weight loss, exercise modification, chondroprotective agents - glucosamine, chondroitin); arthroscopy for debridement

Through Pin

• A form of lateral digital extensor tendon desmotomy or pin fixation
• In veterinary context, "through pin" refers to a transfixation pin used in fracture repair - a Steinmann pin passed transversely through bone for fixation or traction

SECTION 5: BODY CONFORMATION (EQUINE & BOVINE)

5.1 Body Conformation - Equine

• Head: Clean, refined, proportional; large nostrils; large bright eyes
• Neck: Long, muscular, arching crest; well-set into shoulder (no "ewe neck")
• Shoulder: Long, sloping shoulder (45-50°) for long stride and shock absorption
• Withers: Well-defined, not too high; saddle placement landmark
• Back: Short, strong, level; long back = weakness
• Loin: Muscular, broad
• Hindquarters: Rounded, muscular croup; well-defined hindquarter
• Legs: Straight, correct angles; no "base narrow/wide," "toed in/out," "cow hocks," "sickle hocks"
• Hooves: Well-shaped, balanced, no flares

• Straight shoulder → jarring gait, increased concussion → navicular disease
• Sickle hocks → curb, upward fixation of patella
• Cow hocks → bog spavin, bone spavin
• Long toes/low heels → navicular syndrome
• Clubfoot → rotation of coffin bone

SECTION 6: AFFECTIONS OF THE HOOF

6.1 Hoof Conditions

Overgrown Hoof

• Excessive growth of hoof wall due to lack of trimming or inactivity
• Causes: Neglect, systemic illness, laminitis (chronic)
• Treatment: Regular trimming (every 6-8 weeks in horses), corrective shoeing

Overworn Hoof

• Excessive wear of hoof wall faster than growth
• Causes: Hard surfaces, excessive work on concrete/rocky terrain, nutritional deficiencies (biotin, zinc, methionine)
• Signs: Short hoof wall, thin soles, sensitivity
• Treatment: Limit work on hard surfaces, nutritional supplementation, protective shoes, hoof pads

Hoof Cracks (Toe crack, Quarter crack, Bar crack)

• Vertical fissures in hoof wall
• Classified by: location (toe, quarter, heel, bar), depth (superficial/deep), origin (coronet/bearing surface)
• Causes: Dry conditions, nutritional deficiencies, faulty conformation, trauma, overgrown or misshapen feet
• Treatment: Remove cause, correct trimming, stabilize crack (lacing, fiberglass/acrylic repair, bar shoe, screws + wire); severe cracks may need surgical debridement

Sand Cracks

• Cracks originating at the coronary band and extending downward (top-down cracks)
• More serious than grass cracks (bottom-up)
• Often involve sensitive laminae if deep
• Treatment: As for hoof cracks above; keratoma or infectious process underlying must be ruled out

Solar Penetrations

• Foreign bodies (nails, wire, glass) penetrating the sole
• Risk of infection: subsolar abscess, septic pedal osteitis, septic navicular bursa, septic coffin joint
• Management:
  • Radiograph to assess depth and direction
  • Do not remove nail in field if penetrated deep zone (center 2/3 of frog area) - remove in controlled setting
  • Tetanus prophylaxis
  • Surgical debridement + drainage
  • Antibiotics + NSAIDs
  • Farriery: heart bar shoe to protect

Hoof Ulcers (Sole Ulcer / Rusterholz Ulcer)

• Circumscribed lesion at the junction of the sole and bulb of heel (typical site at predilection zone)
• Most common in dairy cattle; associated with laminitis, overcrowding, hard floors
• Signs: Lameness, hemorrhagic/necrotic tissue at sole-bulb junction
• Treatment: Removal of necrotic horn, therapeutic shoeing (wooden block on opposite claw), NSAIDs; treat underlying laminitis

Corns

• Hemorrhage/bruising in the white line zone at the seat of corn (angle between wall and bar, heel area)
• Horses: Caused by ill-fitting shoes pressing on the heel
• Signs: Lameness, pain on hoof testers at heels
• Treatment: Remove shoe, pare away affected horn, rebalance foot, refit shoes

Thrush

• Degenerative condition of the frog with black, foul-smelling discharge
• Caused by anaerobic bacteria (Fusobacterium necrophorum) in wet, dirty conditions
• Signs: Black, putty-like material in frog sulci, necrosis of frog tissue, foul odor; may cause lameness if sensitive tissue involved
• Treatment: Remove necrotic horn, clean and dry frog, apply antiseptics (copper sulfate, iodine, formaldehyde solution); improve management (clean dry bedding)

Canker

• Chronic, hypertrophic, moist pododermatitis affecting the frog and adjacent sole/bars
• Horses; caused by filamentous bacteria; associated with wet conditions
• Signs: Cauliflower-like proliferations on frog; foul smell; less painful than thrush despite extensive lesions
• Treatment: Aggressive surgical debridement under GA; metronidazole, oxytetracycline; dry bandaging; long-term management; high recurrence rate

Side Bone

• Ossification (calcification) of the collateral (lateral and/or medial) cartilages of the foot
• Horses; most common in front feet; associated with concussion (heavy horses, hard surfaces)
• Often incidental finding; may cause lameness if extensive
• Diagnosis: Radiography (palpable hardness of cartilage)
• Treatment: Conservative; corrective shoeing; surgery (surgical division of sidebones) rarely needed

Quittor

• Chronic, septic necrosis of the collateral cartilage of the foot
• Most common in horses on the lateral fore digital cartilage
• Caused by injury or infection tracking from coronary band
• Signs: Discharging sinuses at coronary band, chronic lameness, heat, swelling
• Treatment: Surgical removal of necrotic cartilage (quittor operation); aggressive long-term wound management; antibiotics; guarded prognosis

Keratoma

• Benign neoplastic or hyperplastic growth of keratinized cells within the hoof wall (inner surface)
• Horses most commonly; thought to arise from chronic pressure/irritation of coronary band
• Signs: Chronic progressive lameness; distortion of hoof wall; characteristic hoof wall deviation visible
• Diagnosis: Radiography (radiolucent cavity in hoof wall), MRI
• Treatment: Surgical removal via partial hoof wall resection; good prognosis with complete removal

SECTION 7: REGIONAL SURGERY - EAR & HORN

7.1 Ear Affections - Otitis

• Otitis externa: Inflammation of external ear canal
• Otitis media: Inflammation of middle ear (tympanic cavity)
• Otitis interna: Inflammation of inner ear (labyrinthitis)

• Clean ear canal (saline flush)
• Topical antibiotics + antifungals + anti-inflammatory drops (e.g., Otomax)
• Treat underlying cause
• Chronic/severe: Total Ear Canal Ablation (TECA) + bulla osteotomy (surgery)

7.2 Aural Haematoma

• Aspiration + corticosteroid injection: Simple but high recurrence
• Surgical drainage: Incision on inner (concave) surface of pinna, drain hematoma, place through-and-through mattress sutures (quilting sutures) to obliterate dead space; bandage ear over the head for 3-4 weeks
• Teat cannula/drain placement
• Must treat concurrent otitis to prevent recurrence

7.3 Horn Cancer (Squamous Cell Carcinoma of the Horn Base)

• Most common tumor of cattle, especially Zebu (Bos indicus) breeds in tropical countries
• In India: zebu cattle; predominantly in working bullocks (5-15 years); may be related to chronic irritation, horn fly infestation, UV exposure
• Clinical signs: Progressive destruction of horn tissue, cauliflower-like growth, foul odor, bloody discharge, invasion of horn core and frontal sinuses; lymph node metastasis (parotid, mandibular) in advanced cases
• Histology: Squamous cell carcinoma (well differentiated)
• Diagnosis: Clinical signs + biopsy
• Treatment:
  • Surgical: Amputation of horn (dehorning) + removal of horn core + curettage of frontal sinus; wide surgical margins needed
  • Radiation therapy (telecobalt)
  • Chemotherapy (limited use in cattle)
  • Prognosis: Guarded to poor if sinus involvement or metastasis

7.4 Overgrown/Growth of Horn

• In cattle, buffaloes - horns may grow excessively due to: genetic factors, lack of regular dehorning, nutritional excess
• Scurs: Incompletely formed horns in dehorned animals if periosteum was not fully removed
• Dehorning methods:
  • Chemical (caustic paste/stick) - neonates < 1 week
  • Thermal (hot iron) - calves up to 2-3 weeks
  • Surgical (Barnes dehorner, Gouges, Wire saw, Saw) - adult animals under local anesthesia (cornual nerve block)
  • Rubber ring/elastrator band

SECTION 8: CLEFT PALATE

8.1 Cleft Palate - Acquired & Congenital

• Failure of fusion of palatal shelves during embryonic development
• Often associated with cleft lip (harelip/cheiloschisis)
• Causes: Genetic (CLEFT gene mutations), teratogenic drugs (corticosteroids, griseofulvin, methotrexate), nutritional deficiencies (Vitamin A), viral infections in pregnancy
• Occurs in dogs, cats, cattle, horses
• Signs: Milk regurgitation through nose (milk flowing from nostrils during nursing), aspiration pneumonia, failure to thrive, nasal discharge
• Diagnosis: Direct visualization under sedation/anesthesia; probing the defect

• Trauma (bite wound, foreign body, electric cord injury)
• Surgical iatrogenic
• Pressure necrosis (from feeding tubes)

• Optimal age: 8-12 weeks (after adequate body weight)
• Multiple techniques:
  • Sliding flap technique (Haskell): Transposing overlapping mucoperiosteal flaps
  • Von Langenbeck technique: Bipedicle flaps elevated and moved medially
  • Oral-nasal fistula repair: For small acquired defects
• Multiple surgeries often needed for extensive defects
• Prognosis: Fair to good for small defects; guarded for complete cleft palate; aspiration pneumonia is a major complication

SECTION 9: SALIVARY AFFECTIONS - MUCOCELE

9.1 Salivary Mucocele

1. Cervical mucocele - most common presentation; saliva accumulates in the neck region
2. Sublingual mucocele (Ranula) - saliva under the tongue; large, bluish fluid-filled swelling on floor of mouth
3. Pharyngeal mucocele - dorsal pharyngeal wall; dysphagia, respiratory distress
4. Zygomatic mucocele - near the eye; exophthalmia

• Aspiration of mucoid, stringy, yellowish-brown fluid
• Cytology: Mucin + macrophages (no bacteria, no cellular debris as in abscess)
• Contrast sialography

• Surgical - treatment of choice: mandibular/sublingual gland complex removal (excision of affected gland)
• Marsupalization of ranula (opening the cavity into the oral cavity) - palliative; high recurrence
• Simple drainage alone - very high recurrence rate

SECTION 10: UROLITHIASIS

• Obstructive urolithiasis (most serious in male small ruminants, cats, dogs):
  • Stranguria (straining to urinate), hematuria, dysuria, anuria
  • Distended bladder
  • Uremia signs (anorexia, depression, vomiting, uremic breath)
  • Bladder rupture → uroabdomen (ascites, marked depression)

• Urethral process amputation (if blockage at vermiform appendage)
• Perineal urethrostomy (tube cystostomy temporary; allows dietary dissolution)
• Tube cystostomy (temporary urinary diversion)
• Bladder marsupialization
• Wiring/Ischial urethrostomy

• Manual hydropulsion (retrograde flushing)
• Perineal urethrostomy (PU) for recurrent/refractory cases
• Dietary management (struvite dissolution diets)

• Medical dissolution (struvite, urate, cystine)
• Urohydropropulsion (voiding or catheter-assisted)
• Surgical cystotomy (vesicotomy) for large cystic calculi
• Laser lithotripsy

SECTION 11: AFFECTIONS OF THE EYE

11.1 Examination of the Eye - General

1. Visual assessment: Menace response, dazzle reflex, tracking
2. Periocular region: Swelling, discharge, masses
3. Eyelids: Entropion, ectropion, trichiasis, masses
4. Conjunctiva: Color (pale, red, icteric), chemosis, discharge
5. Cornea: Clarity, vascularization, ulcers (fluorescein stain), edema
6. Anterior chamber: Depth, hypopyon (pus), hyphema (blood), flare (protein)
7. Iris: Color, shape, synechiae
8. Pupil: Size, symmetry, PLR (direct & consensual)
9. Lens: Clarity (cataract), luxation
10. Fundus: Optic disc, retina, vessels (indirect ophthalmoscopy)

• Schirmer Tear Test (STT): Measures aqueous tear production (normal >15 mm/min in dogs)
• Fluorescein stain: Detects corneal epithelial defects (stains ulcers green)
• Tonometry (Tonopen/Schiotz): Intraocular pressure (normal 10-25 mmHg); elevated in glaucoma
• Rose bengal stain: Stains devitalized/dead epithelial cells and mucus

11.2 Conjunctivitis

• Infectious: Bacteria (Staphylococcus, Streptococcus, Moraxella bovis in cattle - IBK), viruses (FHV-1 in cats, CDV in dogs), Chlamydophila felis (cats), Mycoplasma
• Allergic: Environmental allergens (atopy)
• Mechanical: Foreign body, entropion, trichiasis, distichiasis
• Keratoconjunctivitis Sicca (KCS): Dry eye; inadequate tear production

11.3 Corneal Conditions

Corneal Ulcer

• Loss of corneal epithelium ± stroma
• Causes: Trauma, KCS, entropion, corneal dystrophy, herpetic (FHV-1 cats), exposure
• Classification:
  • Superficial: epithelium only
  • Stromal: partial thickness stroma
  • Descemetocoele: only Descemet's membrane remains - surgical emergency (imminent perforation)
  • Perforated ulcer: through all layers + iris prolapse
• Diagnosis: Fluorescein staining (positive uptake)
• Treatment:
  • Topical antibiotics (triple antibiotic, gentamicin); atropine (cycloplegia, pain relief); avoid corticosteroids in ulcerated eye
  • Debridement for indolent ulcers (superficial punctate keratectomy, diamond burr debridement)
  • Surgical: Conjunctival flap (for deep ulcers/descemetocoele), corneoconjunctival transposition, tissue adhesive (cyanoacrylate) for small perforations
  • Third eyelid flap (temporary protection)

11.4 Cataract

• Age: Congenital, juvenile (hereditary - common in Labrador, Cocker Spaniel, Poodle), senile
• Etiology: Hereditary, metabolic (diabetes mellitus - rapid bilateral), traumatic, toxic, uveitis-induced
• Degree: Incipient (<15% opacity), immature (>15%, not complete), mature (complete), hypermature (liquefied)
• Location: Anterior/posterior polar, nuclear, cortical, equatorial

• Surgical extraction - phacoemulsification (ultrasonic fragmentation + aspiration of lens) is gold standard in small animals
• Extracapsular lens extraction (ECLE)
• Intracapsular lens extraction (ICLE)
• Intraocular lens (IOL) implantation after extraction
• Medical: Antioxidants (limited evidence); lanosterol eye drops (emerging research)

SECTION 12: GENITAL SYSTEM

12.1 Genital System - General

• Castration/Orchidectomy: Removal of testes; performed for population control, behavioral modification, cryptorchidism, testicular neoplasia, epididymitis, orchitis
  • Open/closed technique
  • Scrotal vs. prescrotal approach in dogs
  • Standing procedure under sedation in horses (emasculator technique)
• Cryptorchidism: Failure of one or both testes to descend into scrotum
  • Retained testis is at risk for neoplasia (8-14x higher risk in dogs); surgical removal mandatory
  • Inguinal/abdominal exploration depending on location
• Penile conditions: Phimosis (inability to extrude penis), paraphimosis (inability to retract penis - emergency), persistent penile frenulum, penile hematoma (bulls - "broken penis")

• Vaginoscopy/vaginotomy for vaginal masses, strictures
• Episiotomy for dystocia
• Vaginal prolapse - reduction + retention sutures (Bühner suture technique)
• Uterine prolapse - clean, replace, retain; if non-viable → amputation

12.2 Ovariohysterectomy (OHE) - Elective

• Elective sterilization (population control)
• Pyometra (most critical indication in older intact females)
• Ovarian cysts, neoplasia
• Uterine neoplasia, hydrometra, mucometra
• Dystocia (when caesarean section is not feasible)

• Before first heat: 0.05% risk of mammary tumor in dogs
• After 1st heat: 8% risk of mammary tumor
• After 2nd heat: 26% risk of mammary tumor
• Eliminates pyometra, ovarian cysts, false pregnancies, estrus-related behavior

1. Dorsal recumbency, ventral midline incision (umbilicus to pubis)
2. Identify uterine horns, trace to ovaries
3. Place three clamps on ovarian pedicle; ligate the pedicle (ovarian vessels) with absorbable suture between clamps 1 and 2; transect between clamps 2 and 3
4. Trace both horns to uterine body; triple clamp technique on uterine body at cervix
5. Ensure bladder is identified and not incorporated
6. Close abdomen in 3 layers (linea alba, subcutaneous, skin)

SECTION 13: ESOPHAGUS - CHOKE

13.1 Esophageal Obstruction (Choke)

• Horses: Poorly chewed feed (hay, grain), inadequate water intake, rapid eating, dental disease (unable to chew properly), esophageal stricture or mass
• Cattle: Large pieces of root vegetables (turnip, potato, apple), poorly chewed bedding
• Dogs/Cats: Bones, toys, foreign bodies

• Cervical esophagus (pharynx/cranial thoracic inlet) - most common
• Thoracic inlet
• Base of heart (dogs/cats - most difficult to access)

• Horses: Saliva + ingesta drooling from nostrils and mouth; attempts to swallow; neck extension; distress; coughing; regurgitation; feed material from nose
• Cattle: Bloat (if complete obstruction prevents eructation)
• Aspiration pneumonia (major complication)

• Horses:
  1. Sedation (xylazine, detomidine) - head down position
  2. Attempt gentle nasogastric lavage (infuse warm water, intermittent suction)
  3. Antispasmodics (hyoscine butylbromide/buscopan, oxytocin)
  4. NSAIDs for pain and inflammation
  5. Most resolve within 1-2 hours
  6. If unsuccessful: Endoscopic extraction; surgical (esophagotomy) as last resort
• Dogs/Cats:
  • Endoscopic retrieval (preferred)
  • Retrograde flushing
  • Surgery (esophagotomy, esophageal resection/anastomosis) for refractory cases or perforation

SECTION 14: CAPTURE MYOPATHY

• Intense physical exertion → anaerobic muscle metabolism → severe lactic acidosis
• Muscle damage (rhabdomyolysis) → myoglobinuria (brown urine)
• Hyperthermia, electrolyte imbalances, hypoxia
• Depletion of muscle ATP and glycogen
• Oxidative damage to muscle fibers

• Capture shock syndrome: Immediate/peracute; death during or within hours of capture
• Delayed/Ataxic myopathy: Weakness, ataxia, reluctance to rise within 24-72 hours
• Ruptured muscle syndrome: 1-7 days post-capture; muscular swelling, pain, and rupture
• Chronic form: Weight loss, muscle weakness, weeks later

• Minimize pursuit time
• Use appropriate drugs (sedation/immobilization)
• Reduce environmental temperature
• Minimize handling time
• Shade and cooling post-capture

• Supportive: IV fluids (correct acidosis, flush myoglobin from kidneys)
• Sodium bicarbonate to alkalinize urine (protect kidneys)
• Vitamin E + Selenium (antioxidants)
• Dantrolene sodium (reduce muscle contracture)
• NSAIDs, corticosteroids (controversial)
• Anti-anxiety drugs
• Cooling (hyperthermia management)
• Prognosis: Guarded to poor once severe clinical signs present

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