YR3 7 AS HO3 - Intestine Flashcards
Structural/Function Disorders Intestine; Classes
1)Congenital 2)Structural 3)Accidents/displacements
Structural/Function Disorders Intestine - Congenital
1)Atresia 2)Aplasia/Hypoplasia 3)Schistosomus reflexus
Atresia definition; examples
Part of the bowel that is occluded 1)Atresia Ani -Enlarged abdomen, imperforate anus, unable to defecate +/- surgical correction 2)Intestinal Atresia 3)Caecocolic Atresia - lack of fat around intestine 4)Segmental Blind-end Colonic Atresia - inherited in Friesians
Structural/Function Disorders Intestine - Structural; types (e.g.)
Secondary to congenital; 1)Acquired internal blockage e.g. worms, foreign bodies 2)External compression e.g. neoplasia, granuloma 3)Functional paralysis e.g. paralytic ileus, grass sickness
Consequences of intestinal obstruction - Upper vs.. Lower or Simple vs. Strangulated
1)Upper - Acute, severe and rapid w/ haemoconcentration > electrolyte depletion > alkalosis 2)Lower (colon) - less acute (even chronic) > toxaemia 3) Strangulated - engorged segments, fluid & electrolytes lost > toxaemia & shock
Structural/Function Disorders Intestine - Accidents/Displacements types
1)Volvulus/torsion - ‘redgut of sheep’ 2)Intussusception 3)Eventration - surgical wound, umbilical at birth, traumatic, schistosomus reflexus (foetal anomaly) 4)Internal hernia - diaphragmatic, tear in the mesentery/omentum, epiploic foramen & nephrospenic space (horse) 5)External hernia - ventral e.g. pregnancy, umbilical - often inherited, inguinal/scrotal, perineal - male dogs with prostatic disease
In Horses, torsion and volvulus cause
Colic
Miscellaneous disorders of the intestines
1)Intestinal liposuscinosis (‘brown bowel’ dog) 2)Smooth muscles hypertrophy of terminal ileum - pigs & horses 3)Diverticulosis - sheep 4)Intestinal emphysema - pigs 5)Haemomelasma ilei - horses (Strongylus edentatus) 6)Rectal prolapse - pig, sheep, cattle
Intestinal Diverticulosis (sheep)
Cystic mucosal pouches through defects in the intestinal wall
Intestinal Emphysema (pig)
Incidental finding in pigs at slaughter
Changes to normal structure/function in enteritis
1)Irritation > increased mucus secretion 2)Increased exfoliation / desquamation 3)Increased mitotic rate in crypts 4)Necrosis of villous epithelium, contraction of lamina propria > shorting of villi 5)Replacement by cells less differentiated - cuboidal/squamous
Pathogenesis of Enteritis
Necrosis of villous epithelium > crypt hyperplasia. Necrosis in crypts > villi become denuded, mucosa ‘collapses’. Deficient digestion & absorption > Deficient absorption of protein & water > wasting & dehydration. Loss of electrolytes
What is the ultimate result of enteritis
Diarrhoea
Diarrhoea is
Relative excess of water compared to faecal dry matter
Diarrhoea can occur in the small or large bowel and causes
Dehydration, electrolytes depleted, acid-base balance upset
Small Bowel Diarrhoea; types, e.g.
1)Secretory - bacterial enterotoxins e.g. E.coli 2)Malabsorptive - osmotic retention in lumen (MgSO4) e.g. Villus atrophy (TGE) 3)Effusive - hydrostatic/oncotic pressure gradient e.g. inflammation (Salmonella. Clostridium, Yersinia)
Large Bowel Diarrhoea; types, e.g.
1)Loss of absorptive epithelium e.g. ulcers 2)Fatty acid production (osmotic) - products of bacterial fermentation e.g. castor oil 3)Reduction in net absorption e.g. Johne’s 4)Intestines become flaccid, hypomobile
Inflammation of the intestines; types
1)Small intestine - enteritis (duodenitis, jejunitis, ileitis 2)Caecum - typhlitis 3)Ileocaecal valve - typhlodicliditis (ty.phlo.di.cli.di.tis) 5)Colon - colitis 6)Rectum - proctitis
Enteritis; types, cause
1)Lymphoplasmacytic - IBD 2)Eosinophilic - parasites 3)Granulomatous - Johne’s 4)Pseudomembranous - Salmonella 5)Necrotic - Parvo 6)Catarrhal - parasites
Colitis; types, cause
1)Lymphoplasmacytic 2)Histolytic - Boxer Colitis 3)Ulcerative - Shigella / Pyogranulomatous - Johne’s 4)Dysentery - Swine-Brachyspira hyodyseteriae 5)Haematochezia
Chronic Enteritis / Colitis - Parasites
Eosinophilc
Chronic Enteritis / Colitis - Bacterial
Johne’s disease - granulomatous
Atrophic Enteritis
Sprue 1)Stunting & atrophy of villi 2)Fusion of villi 3)Covered with less differentiated epithelium & fewer microvilli 4)Increased inflammatory cells in lamina propria 5)May be manifestation of chronic disease
Viral Enteritis; name, species
1)Rotavirus - calves 2)Coronavirus - calves, pigs, cats, dogs 3)Parvovirus - cats, dogs 4)Morbillivirus - rinderpest, distemper in pups 5)Pestivirus - BVD, Hog Cholera 6)Herpesvirus
Rotavirus; pathogenesis
Upper small intestine > superficial damage to villi > villus atrophy > osmotic diarrhoea. Secondary bacterial (E.coli) or protozoa (Cryptosporidium) infection. Neonates that receive no colostrum prone
Coronavirus; pathogenesis
Lower small intestine & colon > superficial damage to villi > villus atrophy > osmotic diarrhoea
Coronavirus; pigs
1)Transmissible gastroenteritis (TGE) 2)Epidemic diarrhoea 3)Vomiting & wasting disease
Coronavirus; cats
Feline Infectious Peritonitis 1)Immune complex form (delayed hypersensitivity reaction) 2)Vasculitis & Multifocal granulomas 3)Mixed Inflammatory infiltrates 4)Wet and dry forms 5)Enteritis in 6-12wk kittens > kitten mortality complex & cardiomyopathy
Canine Parvovirus Enteritis; intestinal lesions
Macro: Serosal surface - Fibrin strands, patchy hyperaemia, surface appear finely granular, Mucosal surface - blood-tinged contents, surface dull, yellow & fissured and lacking epithelium. Micro: crypt regeneration and nuclear inclusion
Feline Infectious Enteritis; intestinal lesions
Panleukopenia. Intestine empty; mucosa may be covered with mucus or have scattered petechiae
Parvovirus Enteritis; affected tissues
1)Intestinal crypts 2)Bone marrow (esp. cats) 3)Myocardium(3-8wk pups) 4)Lymphoid tissue (thymic atrophy) 5)Cerebellar hypoplasia (kittens in utero) 6)Nuclear inclusions
Classical Swine Fever; lesions
Hog Cholera - Very sick pig 1)’Turkey egg’ kidney 2)’Button ulcers’ colon. DD - Salmonellosis
Bovine Virus Diarrhoea; lesions
Prolapsed crypt in Peyer’s patch in ileum. Crypts contain abscesses
Bacterial Enteritis; name
E.coli, Salmonellosis, Yersiniosis, Paratuberculosis, Lawsonia intracellularis, Campylobacter infections, Swine dysentery, Spirochaetal colitis, Rhodococcus equi, Clostridial diseases
Enteritis - Escherichia coli; disease
Enteric colibacillosis aka ‘white scours’ - new born calves
Enteritis - Escherichia coli; pathogens
1)Pathogenic strains Ruminants:K99 & Pig:K88 2) Enterotoxins > Enterotoxigenic (ETEC), Enteropathogenic (EPEC), Enteroinvasive (EIEC), Enterohaemorrhagic (EHEC) & Verotoxic (VTEC)