20 Food Animal Intestinal/Anorectal Surgery Part 1

• Food Animal Intestinal/Anorectal Surgery is covered in VCS878.

Surgical Disease of GIT

• In calves less than 1 year old, surgical GIT diseases include umbilical entrapment/incarceration, intussusception, anomalous fibrovascular bands, intestinal volvulus, abomasal displacements (2 weeks-2 months), trichobezoars, and atresia.
• Rectal prolapse can occur in calves less than five days old.
• In cattle older than 1 year, surgical GIT diseases include rumen issues, LDA/RDA/RVA, intussusception, intestinal volvulus (root of mesentery), cecal dilatation/volvulus, and potentially hemorrhagic bowel syndrome.

Indications for Exploratory Celiotomy

• When physical examination needs extension.
• When a patient passes scant or no feces for over 24 hours, especially with mucous or frank blood.
• If acute, severe, or persistent abdominal pain is present.
• If marked hypochloremic metabolic alkalosis is present.

Selecting Surgical Approach

• The right paralumbar fossa is almost exclusively used for intestinal access.

Laparotomy: Right Paralumbar Fossa

• Allows for thorough exploration.
• Structures that can be explored include the liver and gall bladder, abomasum/omasum/reticulum (+/- rumen), small intestines, kidneys, large intestine/spiral colon, and uterus/ovaries.

Laparotomy: Left Paralumbar Fossa

• Offers limited access.
• Excellent for rumen, spleen, and abomasum access.
• Also excellent for uterus/ovaries.
• Palpation is limited to the SI and Kidneys.

Ventral Midline

• Offers very limited access.
• Easier in neonates due to size.
• Still requires right paralumbar approach for atresia coli.
• Primarily allows access to the abomasum, liver, and uterus.

Position

• Standing or recumbent positions can be used.
• Each position has its own advantages and disadvantages.

Intussusception

• Clinical presentation depends on duration.
• Often has a slow progression and vague clinical signs.
• Scant feces and intestinal distention are common.
• Can be diagnosed with palpation/ultrasound.
• Abdominal contour can be affected.
• Can occur at any age.
• Risk factors include calves (diarrhea), chronic diarrhea, any indigestion, and parasitic enteritis.
• Nodules in the intestinal wall (e.g., granuloma or adenocarcinoma) can be predisposing factors.

Surgical Procedure: Right PLF

• General anesthesia may be considered.
• Exteriorize small intestine.
• Isolate affected segment.
• Use isolate segment with Doyen intestinal forceps
• Resect segment, addressing mesentery vascular ligation and intestinal transection.
• Perform end-to-end anastomosis using interrupted simple continuous, inverting monofilament, absorbable suture.

Resection/Anastomosis Surgical Procedure: Ruminant Features

• Thin bowel makes separating mucosa from other layers difficult.
• Ensure One Layer closure
• Accurate placement of closures is important.
• The mesentery Vessels are Hidden in Fat.
• Overlapping interrupted sutures are often used instead of locating and ligating the major vessel feeding the segment.

Anomalous Fibrovascular Bands ("gut tie")

• History includes acute abdominal pain, depression, arched back, stretched legs, and a distended abdomen.
• Often seen in castrated calves > 8 months or animals with umbilical infection as neonates.

Lumen Obstructions

• Bezoars and twine are examples of lumen obstructions.
• Often present with slow onset clinical signs of obstruction.
• Hypochloremic metabolic alkalosis is common
• High Rumen [Chloride]
• Rectal examination may reveal no feces or distended loops.
• Abdomen distention confirmed by palpation or ultrasound.

Hemorrhagic Bowel Syndrome

• The cause is multifactorial, including Clostridium perfringens Type A (beta toxin?) and fungal intestinal flora (Aspergillus).
• History includes acute drop in milk, depression (+/- head press), and bloody feces (small volume).
• Prognosis is poor with both medical and surgical management.
• Options include Enterotomy/Intestinal resection?
• Medical therapy includes PPG, IV fluids, oral MgOH, and pain management.

Cecal Dilatation Volvulus

• Occurs most often in dairy cows, but can be seen in beef cows.
• Clinical Recognition usually prolonged.
• All same causes as DA
• Concentrates increase VFA.
• Hypocalcemia
• Feed changes
• Signs include decreased milk, decreased feed intake.
• Diarrhea (indigestion) followed by empty rectum.
• Ping can be heard on right paralumbar fossa.
• Rectal palpation reveals no feces, but a distended viscus with a blind end ("vienna bread loaf") can be found.

Cecal Dilatation / Volvulus

• Cecal volvulus is an emergency.
• Requires right PLF laparotomy.
• Perform typhlotomy for decompression.
• Resect apex of cecum if comprimised
• Post-operative care includes NSAIDs, antibiotics, and feeding of roughage.
• Prognosis is good with early recognition and has less than 10% recurrence rate.

Rectal Prolapse

• Treatment includes using products such as "Preparation H" to assist with prolapse.