Companion Animal Diseases - Digestive Tract Diseases Notes

Companion Animal Diseases - Digestive Tract Diseases

General Structure of the Gastrointestinal Tract (GIT)
  • Mesentery: The fold of tissue that attaches organs to the body wall.
  • Mucosa: The innermost layer lining the gastrointestinal tract.
  • Submucosa: A layer of connective tissue that supports the mucosa.
  • Circular Muscle Layer: Controls the movement of the digestive tract via contractions.
  • Longitudinal Muscle Layer: Helps in shortening and lengthening the digestive tube to facilitate movement.
  • Serosa: The outer layer, providing protection and lubrication to the gastrointestinal organs.
Physiologic Control Points of GIT Activity
  • Autonomic Nervous System: Key player in motility, peristalsis, and secretion.
    • Parasympathetic Innervation: Increases motility and secretion of digestive juices.
    • Sympathetic Innervation: Decreases motility, secretion, and sphincter tone.
  • GI Hormones: Hormones such as gastrin, secretin, and cholecystokinin stimulate local digestive activity.
  • Intraluminal Events: Conditions like bacterial overgrowth and obstructions can paralyze motility.
History of Vomiting and Diarrhea at Intake Exam
  • Start from the last period of known normal health and trace forward for clues.
  • Essential questions:
    • Normal diet?
    • Exposure to possible toxins or dietary changes ("garbage gut").
  • Diagnosis Dilemma: Decide if vomiting is self-limiting or indicative of a serious condition, weighing the "watch and wait" approach.
Vomiting vs. Regurgitation
  • Vomiting:
    • Forceful reverse peristalsis resulting in the emission of gastric contents.
    • Triggered by local irritation or central CRTZ stimulation.
  • Regurgitation:
    • Passive process occurring shortly after eating, often characterized by undigested food mixed with mucus without force.
Signs of Concern in Diarrhea
  • Presence of vomiting or nausea (drooling, lip smacking).
  • Fever, decreased appetite, lethargy, abdominal pain, or weight loss.
  • Significant amounts of blood in feces may indicate a serious issue.
Stool Quality Assessment
  • Dog Fecal Scoring Chart (Score 1 to 7):
    • 1: Very hard and dry; requires effort to expel.
    • 2: Firm but not hard; segmented appearance.
    • 3: Log-shaped; little visible segmentation, moist.
    • 4: Moist, loses form when picked up.
    • 5: Distinct piles, not formed logs.
    • 6: Texture, no defined shape; piles or spots.
    • 7: Watery; no texture, flat puddles.
The GIT Microbiome
  • Importance in conditions like diabetes, obesity, chronic inflammation, nutrition, and cancer.
  • Plays a critical role in digestive health and metabolism.
Abdominal Palpation Technique for Technicians
  1. Press fingers flat toward midline, starting cranially.
  2. Elevate front legs to allow viscera to shift caudally.
  3. Proceed caudally, identifying pain, masses, or gas accumulation.
Common GIT Conditions and Diagnoses
  • Gastric Endoscopy: Usually performed in specialty or emergency settings.
  • Esophageal Ulcers/Strictures: Often secondary to conditions like GERD or chronic vomiting.
  • Radiographic Assessments: Evaluating for foreign bodies (FBs) can include positive contrast gastrograms.
  • GIT Ultrasonography: Useful for imaging the liver, stomach, and intestines.
Canine Pancreatitis
  • Acute Canine Pancreatitis: Requires ICU monitoring, IV fluids, antiemetics, and careful nutrition management.
  • Chronic Pancreatitis: Symptoms like recurrence and damage accumulate; dietary fat sensitivity is crucial.
Feline Pancreatitis and Triaditis
  • Feline Triaditis: Concomitant inflammation of the pancreas, liver, and intestines often presents with severe anorexia and nausea.
Management of Gastrointestinal Disorders
  • Dietary Adjustments: Specialized veterinary diets; prebiotics and probiotics support gut health.
  • Medications: Utilization of antiemetics, analgesics, and specific treatments for conditions like inflammatory bowel disease (IBD) and pancreatitis.
Additional Notes on Surgery and Interventions
  • Esophageal FB Removal: Important for cases like PRAA where esophageal compression is present.
  • Preventing GDV (Gastric Dilatation Volvulus): Time-sensitive interventions, including gastropexy and decompression strategies.