Pathology of the Alimentary Tract II: Stomach and Abomasum from University of Surrey

Acknowledgment

Sarhad Alnajjar 8 UNIVERSITY OF SURREY Acknowledgment to Dr. Davide Messina and Dr. Josue DiazPathology of the alimentary tract I and II

Overview of Teaching

Overview of teaching UNIVERSITY OF SURREY Pathology of the alimentary tract: · Lecture I: · Introduction · Oral cavity, tongue, salivary gland, teeth, oesophagus · Lecture II: · Stomach · Abomasum · Lecture III: · IntestinesUNIVERSITY OF

Learning Objectives: Stomach and Abomasum

Pathology of the alimentary tract I and II Learning objectives: stomach, abomasum REY For each of the following disease processes of the stomach, abomasum

1. Gastric dilation, displacement, and volvulus
2. Inflammation: gastritis, abomasitis
3. Gastric ulceration
4. Uremic gastropathy
5. Toxic gastropathy
6. Neoplasia

… by the end of this lecture you should be able to: · Understand what are the causes, development and consequences of them · Recognise and describe their lesions and agents using appropriate terminologyPathology of the alimentary tract II

Pathology of the Stomach and Abomasum Overview

Pathology of the stomach and abomasum Overview · Physical influences · Acute gastric dilation & volvulus (GDV) · Abomasal displacement (Dr Robert Lawrence) · Gastric dilation, impaction and rupture · Gastric ulcers · Gastritis · Parasites (Dr Martha Betson) • NeoplasiaPathology of the alimentary tract I and II

Gastric Dilation, Displacement, and Volvulus (GDV)

Predisposing Factors and Pathogenesis of GDV

Gastric dilation, displacement, and volvulus (GDV) Predisposing factors and pathogenesis · Large, deep-chested dog breeds . Gas, fluid, or feed block the cardia, which prevents eructation and emesis · With gastric rotation, the pylorus is obstructed, which prevents passage of contents into the small intestine · The gas is probably the result of aerophagia or may come from carbon dioxide produced by physiologic processes · Repeated episodes of gastric dilation result in stretching and relaxation of the gastrohepatic ligament · Gastric rotation occurs due to recurrent dilation, overfeeding, or postprandial exercisePathology of the alimentary tract I and II

Rotation and Infarction in GDV

Gastric dilation, displacement, and volvulus (GDV) Rotation and Infarction · Severe abdominal distension · Pathogenesis & consequences: • Clock-wise rotation on a ventrodorsal axis (180 or 360 degrees) · V-shaped bending of enlarged spleen · Venous (haemorrhagic) infarction • Compression of diaphragm, vena cava and portal vein > \venous return › Į cardiac output & perfusion of abdominal viscera -> shock -> death · Rupture of the stomach · Hereditary predisposition? German shepherds, Irish Setters, etc. A B C D Monnet, E. (2003). Gastric dilatation-volvulus syndrome in dogs. Veterinary Clinics: Small Animal Practice, 33(5), 987-1005. On necropsy, the stomach is generally rotated clockwise when viewed from behind, and the spleen is displaced to the right in a "v" shape.A Figure 2. (A) Right lateral radiograph of a dog with a normal stomach. Note the ventrally located, fluid-filled pylorus (orange circle). https://todaysveterinarypractice.com/gastroenterology/diag nosing-canine-abdominal-organ-torsions/ B Figure 2. the craniodorsally located, compartmentalized, gas-filled pylorus (blue arrows). The mottled, soft tissue-opacity material within the body/fundus of the stomach is likely normal ingesta. This dog also has an enlarged and abnormally positioned spleen (orange asterisks) as well as caudally displaced small bowel that is diffusely dilated with a moderate volume of gas (yellow asterisk).Pathology of the alimentary tract I and II

Infarction of the Wall in GDV

Gastric dilation, displacement, and volvulus (GDV) Infarction of the wall (dark red) Rotation on its mesenteric axisPathology of the alimentary tract I and II

Gastritis: General Patterns of Inflammation

Causes of Gastritis by Species

Gastritis: general, patterns of inflammation Inflammation (general) · Acute/chronic · Catarrhal (initial or mild) · Haemorrhagic Clostridia Uraemia Fungal · Ulcerative/necrotizing NSAIDS Uraemia · Proliferative/hyperplastic Ostertagia sp., etc. P E Acute Chronic Causes (per species) Dogs & cats · Uraemia · Helicobacter? · Parasites • Allergic/immune-mediated Pigs · Infectious · Colibacillosis · Salmonellosis Ruminants · Clostridia (braxy) · Fungi (Mucor, Rhizopus, Absidia, Aspergillus) · Parasites (Haemonchus, Ostertagia, Trichostrongylus) Horses · Parasites (gastric bots, Draschia, Trychostrongylus)Pathology of the alimentary tract I and II

Traumatic Gastritis from Foreign Bodies

Gastritis: 1. Traumatic gastritis: ingestion of foreign bodies (dogs and cats) · corn cobs · sticks · stones · bones · string · balls · fishing hooks · stone fruit pips · toys · socks/stockings · many more ... http://www.oldstonevets.com/foreign-body-ingestion-in-dogs/ https://www.veterinaryradiology.net/28/pets-will-eat-the-strangest-things/ https://www.veterinaryradiology.net/28/pets-will-eat-the-strangest-things/ A B Akanbi, O. B., Adam, M., Jegede, H. O., Ajadi, A., Atata, J. A., Raufu, I., ... & Shoyinka, S. V. (2020). Fatal multiple intestinal intussusceptions and torsion secondary to a non-degradable foreign body gastrointestinal obstruction in a captive Lion (Panthera leo). Braz J Vet Pathol, 13(3), 609-614.Pathology of the alimentary tract I and II

Gastritis and Abomasitis Causes

Gastritis, abomasitis: Helicobacter spp .: stomach of dogs and cats (under debate) Mycotic gastritis: granulomatous inflammation by Histoplasma capsulatum (cats, dogs) Parasitic gastritis (*see lectures by Dr Martha Betson) · Gasterophilus spp. (horses) · Hyostrongylus rubidus (pigs) · Trichostrongylus axei (horses) · Physaloptera spp. (cat, dog) · Haemonchus contortus (small ruminants) · Ostertagia ostertagi (cattle), O. circumcincta (small ruminants) VEPathology of the alimentary tract I and II

Braxy and Mycotic Abomasitis

Gastritis, abomasitis: Please see lectures by Dr. Arnoud van Vliet & Prof Rob La Ragione 'Braxy": . Caused by Clostridium septicum · Hemorrhagic and necrotizing abomasitis · Lambs > calves . Usually associated with cold weather F53704, Clostridal abomasitis, Braxy, submitted by KING. Accessible at: https://davisthompsonfoundation.org/image-detail?image=F53704 F53703, Clostridial abomasitis, Braxy, submitted by KING. Accessible at: https://davisthompsonfoundation.org/image-detail?image=F53703Pathology of the alimentary tract I and II Mycotic abomasitis · Angioinvasive fungi such as Aspergillus, Mucor, Rhizopus, Absidia, Mortierella spp. . Results in vasculitis and thrombosis -> hemorrhagic infarction in the mucosa · Round, target-like lesions are typical of fungal infections Veterinary Medicine @ Copyright Cornell i SPEC F51542, Multifocal, abomasal, mycotic abomasitis, submitted by KING. Accessible at: https://davisthompsonfoundation.org/image-detail?image=F51542 F55485, Subacute mycotic abomasitis, submitted by KING. Accessible at: https://davisthompsonfoundation.org/image-detail?image=F55485Pathology of the alimentary tract I and II

Gastric Ulceration: General Causes and Pathogenesis

Causes of Gastric Ulceration

Gastric ulceration: general · How does it happen: o Gastric or abomasal ulcers (peptic ulcers) can be seen incidentally in any species o Generally, stress + mucosal hypoperfusion (imbalance between the necrotizing effects of gastric acid/pepsin secretion and mucosal protective mechanisms) o Non-steroidal anti-inflammatory drugs (NSAIDs) in high doses (depress prostaglandin formation, leading to decreased secretion of protective bicarbonate) Phenylbutazone 20% Injection 200 mg / mL KEEP OUT OF REACH OF CHILDREN FOR HORSES ONLY CAUTION: Federal law restricts this drug to use by or on the order of a licensed veterinarian NET CONTENTS: 100 ml ANADA 200-371, Approved by FJA Aspen® VETERINARY. RESOURCES" LMPathology of the alimentary tract I and II Gastric ulceration: general Causes 1. Local mucosal physical injury 2. Local hypoperfusion and ischemia (stress; humans > animals) 3. High gastric acidity · Mast cell tumours (secrete histamine; dogs) histamine release, leading to acid hyperexcretion and microvascular effects. · Zoellinger-Ellison syndrome (hypergastrinaemia) tumor-associated cause is gastrin-secreting pancreatic islet cell tumors, or gastrinomas 4. NSAIDs (esp. horses; equine gastric ulcerative syndrome [EGUS]) Į PG -> vasoconstriction > Į mucus production > necrosis 5. Uraemia +/- damage to endothelial cells > vascular compromise + 1 ammonia secretion > caustic injury > necrosis 6. Multifactorial in pigs (finely ground rations, fermentation of sugars, stress) î Carbohydrate + bacteria > hyperkeratosis + erosions 7. Infection/inflammation · Angioinvasive fungi in cattle Fungi in rumen + change pH (Į) > vascular injury > necrosis o · Helicobacter (Humans>animals)

Pathogenesis and Main Signs of Gastric Ulceration

Pathogenesis Epithelial necrosis erosion > ulceration > bleeding > perforation peritonitis Main signs · Haematemesis · Melena · Anaemia · Abdominal painPathology of the alimentary tract I and II

Gastric Ulceration in Pigs and Horses

Gastric ulceration · Pigs: at the pars esophagea, frequently bleed, and can cause exsanguination · Horses: in foals (idiopathic); adults (NSAIDs - gastric ulceration, right dorsal colitis and renal papillary necrosis) EQUINE PORCINEPathology of the alimentary tract I and II

Uremic Gastropathy

Uremic gastropathy · Dogs, cats: due to chronic renal disease · Gross findings: oedema, haemorrhage, ulceration . Pathogenesis: vascular damage (angiopathy) from uremic toxins ulceration, necrosis > • Mineralization 96854 3 4 F21439) UREMIC GASTROPATHY,/submitted by HOLSHUH. Accessible at: https://davisthompsonfoundation.org/image-detail?image=F21439 F29438, 91.4303 K9 gastric mucosa mineralization (Uremic Gastropathy), submitted by RICHARD JAKOWSKI. Accessible at: https://davisthompsonfoundation.org/image-detail?image=F29438 . mmPathology of the alimentary tract I and II

Toxic Gastropathies

Blister Beetle Toxicosis

Toxic gastropathies 1. Blister beetle toxicosis: . Horses eating alfalfa hay infested with blister beetles · Necrohemorrhagic gastroenteritis, hemorrhagic ulcers in the bladder, and myocardial necrosis · Causative toxin: cantharidin

Heavy Metal Toxicosis

2. Heavy metal toxicosis: · Arsenic, zinc · Haemorrhage, necrosis, and ulceration in the stomach or abomasum F23954, CANTHARIDIN TOXICITY, submitted by CHAPMAN. Accessible at: https://davisthompsonfoundation.org/image-detail?image=F23954Pathology of the alimentary tract I and II

Gastric Neoplasia Classification

Gastric neoplasia Classification · Epithelial · Polyp/adenoma (from mucosal lining and glands) (dog, cat) · Adenocarcinoma (from mucosal lining and glands) (dog, cat) · Squamous cell carcinoma (from squamous mucosa) (horse); linked to equine papillomavirus-2 infection · Mesenchymal · Leiomyoma/leiomyosarcoma (from muscle layer/ tunica muscularis) (dog, cat) . Round cell · Lymphoma (from mucosa-associated lymphoid tissue) (all species)