Digestive System Disorders PDF

GENERAL PRINCIPL ES OF VETERINARY MEDICINE PHEBE M. VALDEZ, DVM DIGESTIVE SYSTEM DISORDERS DIGESTIVE TRACT DIGESTIVE TRACT DIGESTIVE TRACT Primary Functions Motility Secretion Digestion Absorption DIGESTIVE TRACT ABNORMALITIES IN MOTILITY Hypermotility or hy...

GENERAL PRINCIPL ES OF VETERINARY MEDICINE PHEBE M. VALDEZ, DVM DIGESTIVE SYSTEM DISORDERS DIGESTIVE TRACT DIGESTIVE TRACT DIGESTIVE TRACT Primary Functions Motility Secretion Digestion Absorption DIGESTIVE TRACT ABNORMALITIES IN MOTILITY Hypermotility or hypomotility (Peristalsis) Distension of segments of the tract (Accumulation) Abdominal pain (Stretching of the wall) Dehydration and shock (Loss in fluid and electrolytes) DIGESTIVE TRACT ABNORMALITIES IN SECRETION Undigested lactose causes diarrhea by its hyperosmotic effect The intestinal lactase activity of foals is at its highest level at birth, gradually declines until the fourth month of age, and then disappears from adults before their fourth year. DIGESTIVE TRACT ABNORMALITIES IN DIGESTIVE FUNCTION Failure to provide the correct diet, prolonged starvation or inappetence, and hyperacidity such as occurs in engorgement on grain all result in impairment of microbial digestion 75% of a liquid marker can be emptied from the stomach in 30 minutes and be in the cecum in 2 hours DIGESTIVE TRACT ABNORMALITIES IN ABSORPTION Can be adversely affected by increased motility or by disease of the intestinal mucosa  VOMITING Forceful ejection of contents of the stomach and the proximal small intestine through the mouth (complex motor disturbance of the alimentary tract) Emetic center : Located in medulla oblongata in brain.  VOMITING True vomiting occurs in monogastric animals. True vomiting is not a feature of gastric diseases in horses. Nausea Retching  VOMITING 1. True vomiting occurs in monogastric animals. True vomiting is not a feature of gastric diseases in horses. Nausea Retching 2. Projectile Vomiting not accompanied by retching movements result of overloading  VOMITING True vomiting occurs in monogastric animals. True vomiting is not a feature of gastric diseases in horses. Nausea Retching  DIARRHEA Increased frequency of defecation accompanied by feces that contain an increased concentration n of water and decrease in dry matter content. Abnormalities of peristalsis and segmentation usually occur together DIARRHEA= Increased peristalsis→increased caudal flow→ decreased intestinal transit time  DIARRHEA COMMON CAUSES OF DIARRHEA: Malabsorption, e.g., caused by villous atrophy and in hypocuprosis (caused by molybdenum excess) Neurogenic diarrhea as in excitement Local structural lesions of the stomach or intestine, including the following: Ulcer, e.g., of the abomasum or stomach Tumor, e.g., intestinal adenocarcinoma  DIARRHEA COMMON CAUSES OF DIARRHEA: Indigestible diet, e.g., lactose intolerance in foals Carbohydrate engorgement in cattle In some cases of ileal hypertrophy, ileitis, diverticulitis, and adenomatosis Terminal stages of congestive heart failure (visceral edema) Malabsorption syndromes (monogastric)- There is always failure to grow or maintain body weight (BW), in spite of an apparently normal appetite and an adequate diet.  CONSTIPATION Decreased frequency of defecation accompanied by feces that contain a decreased concentration of water. (Hard to Dry of small bulk feces) True Constipation- failure to defecate and impaction of the rectum with feces May also occur when defecation is painful, such as in cattle with acute traumatic reticuloperitonitis  SCANT FECES Small quantities of feces, which may be dry or soft Outflow Abnormality Common Causes: Diseases of the forestomach and abomasum causing failure of outflow Impaction of the large intestine in the horse and the sow Severe debility, as in old age Deficient dietary bulk, usually fiber Chronic dehydration More of this: pp 180 Diseases of the Alimentary tract  ILEUS (ADYNAMIC AND DYNAMIC ILEUS) ADYNAMIC ILEUS (Paralytic Ileus)- state of functional obstruction of the intestines or failure of peristalsis loss of intestinal tone and motility as a result of reflex inhibition DYNAMIC (Mechanical Ileus)- state of physical obstruction. Physical obstruction of the intestines and torsion of the stomach must be corrected surgically.  ILEUS (ADYNAMIC AND DYNAMIC ILEUS) Postoperative ileus of the small and large intestines is a common complication of surgical treatment for colic in the horse  ALIMENTARY TRACT HEMORRHAGE Gastric or abomasal (rarely duodenal) ulcers Severe hemorrhagic enteritis Structural lesions of the intestinal wall, e.g., adenomatosis, neoplasia Infestation with blood-sucking nematodes, e.g., bunostomiasis, Local vascular engorgement or obstruction as in intussusception and verminous thrombosis  ALIMENTARY TRACT HEMORRHAGE Hemorrhage into the stomach results in the formation of acid hematin Feces have a black or very dark brown, tarry appearance (melena) If the blood originates in the small intestine, the feces may be brown-black If it originates in the colon or cecum, the blood is unchanged and gives the feces an even red Lower colon and rectum, clots of whole blood (hematochezia)  SIMPLE INDIGESTION Commonly occurs in cattle Most cases recover spontaneously. Dietary abnormalities of minor degree like Indigestible Roughage, particularly when protein intake is low, Moldy, overheated and frosted Moderate excesses of grain and concentrate intake. Prolonged or Heavy oral dosing with antimicrobials  INDIGESTION IN CALVES FED MILK REPLACERS For calves with ruminal development (2–3 weeks and older) Insufficient closure of reticular groove while drinking milk. Milk enter rumen decreasing the pH of rumen and increasing lactate concentration Upon drinking milk, the oesophageal (reticular) groove (sulcus retículi) is activated and the milk is shunted directly past the forestomachs to the abomasum  RUMINAL TYMPANY Ruminal tympany is the excessive retention of gases of fermentation with abnormal distension of the rumen and reticulum Overdistended rumen eventually compromise respiration by limiting diaphragm movement  RUMINAL TYMPANY Frothy bloat is associated with ingestion of feeds that produce a stable froth that is not easily expelled from the rumen. The froth is often derived from a combination of salivary mucoproteins, protozoal or bacterial proteins, and proteins, pectins, saponins, or hemicellulose associated with ingested leaves or grain. Free-gas bloat is less related to feeds ingested; rather, it is caused by rumen atony or by physical or pathological problems that prevent normal gas eructation RUMINAL TYMPANY  RUMINAL LACTACIDOSIS The sudden ingestion of toxic doses of carbohydrate rich feed such as grain Feeding of excessive amounts of rapidly fermentable carbohydrates Sub acute ruminal acidosis in dairy cattle; laminitis, intermittent diarrhea, Sub optimal feed intake, liver abscess, haemoptysis, epistaxis and pulmonary haemorrhage. Laminitis is characterized by ridges in dorsal hoof wall, sole ulceration white line lesion, sole hemorrhage end misshapen hooves. RUMINAL LACTACIDOSIS  LEFT-SIDE DISPLACEMENT OF THE ABOMASUM Multifactorial RISK FACTORS Greatest risk at 4-7 years of age. Dairy cattle and Female cattle were at a higher risk Occurs throughout the year Parturition, atonic or distended abomasum-common precipitating factors Concurrent diseases Pre-existing subclinical ketosis Hypocalcemia Genetic predisposition Unusual activity, including jumping LEFT-SIDE DISPLACEMENT OF THE ABOMASUM  RIGHT-SIDE DISPLACEMENT OF THE ABOMASUM Atony is the precursor of dilatation and displacement, and consequently abomasal volvulus Dilatation and Displacement Phase Volvulus Phase  E NTER ITIS IN C LU DI N G MALAB SOR P TION, E NTE R OP ATH Y, AN D DI AR R H E A Enteritis is associated with abnormal intestinal motility patterns that generally result in decreased small intestinal transit time (SITT) through a combination of decreased phasic contractions and increased aboral giant contractions. Osmotic diarrhoea Exudative diarrhoea Secretory diarrhoea Abnormal intestinal motility  E NTER ITIS IN C LU DI N G MALAB SOR P TION, E NTE R OP ATH Y, AN D DI AR R H E A OSMOTIC- when substances within the lumen of the intestine increase the osmotic pressure over a greater than normal length of intestine. The fluid is not reabsorbed and accumulates in the lumen saline purgatives, overfeeding, indigestible feeds, and disaccharidase deficiencies; TGE virus, coronavirus infection  E NTER ITIS IN C LU DI N G MALAB SOR P TION, E NTE R OP ATH Y, AN D DI AR R H E A EXUDATIVE- Acute or chronic inflammation or necrosis of the intestinal mucosa results in a net increase in fluid production bacteria, viruses, fungi, protozoa, chemical agents, and tumors Enteric salmonellosis, Swine dysentery, BVD  E NTER ITIS IN C LU DI N G MALAB SOR P TION, E NTE R OP ATH Y, AN D DI AR R H E A SECRETORY- secretory–absorptive imbalance results in a large net increase in fluid secretion with little if any structural change in the mucosal cells. The villi, along with their digestive and absorptive capabilities, remain intact. The crypts also remain intact; however, their secretion is increased beyond the absorptive capacity of the intestines, resulting in diarrhea  E NTER ITIS IN C LU DI N G MALAB SOR P TION, E NTE R OP ATH Y, AN D DI AR R H E A ABNORMAL INTESTINAL MOTILITY- reduced intestinal absorption caused by rapid passage of intestinal fluids in an otherwise normal intestine Hyperexcitability, convulsions, and the stress of unexpected sudden confinement Increased peristalsis= Intestinal hurry; during transportation  MEGAESOPHAGUS Esophageal dilation and hypomotility Can be a primary disorder or secondary to esophageal obstruction or neuromuscular dysfunction Megaesophagus is the most common cause of regurgitation in dogs Regurgitation is the spitting up of food from the esophagus or stomach without nausea or forceful contractions of the abdominal muscles. ANNOUNCEMENT Quiz Next Meeting Read on Liver, Peritoneum, Cardiovascular THAT’S A WRAP! SEE YOU NEXT MEETING!