VPM 221 VPM 221 VPM 221 VPM 221 P th l f th P th l f th Pathology of the Pathology of the alimentary system alimentary system alimentary system alimentary system and peritoneum and peritoneum Dr. Enrique M. Aburto Dr. Enrique M. Aburto Dr. Enrique M. Aburto Dr. Enrique M. Aburto Fall 2008 Fall 2008 Fall 2008 Fall 2008
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VPM 221VPM 221VPM 221VPM 221
P th l f thP th l f thPathology of the Pathology of the alimentary systemalimentary systemalimentary system alimentary system
and peritoneumand peritoneum
Dr. Enrique M. AburtoDr. Enrique M. AburtoDr. Enrique M. AburtoDr. Enrique M. Aburto
Fall 2008Fall 2008Fall 2008Fall 2008
VPM 221VPM 221
• TextbooksTextbooks– Pathologic Basis of Veterinary Medicine,
ed. 1997Tumors in Domestic Animals Meuten 4th ed– Tumors in Domestic Animals, Meuten, 4th ed. 2002
IntroductionIntroduction
• MouthMouth• Esophagus
St h• Stomach• Intestines• Peritoneum• Liver & Pancreas (dealt with separately)Liver & Pancreas (dealt with separately)
Pathology of Alimentary System and Peritoneum:
The Big Picture▪StomatitidesStomatitides ▪Oral tumors ▪Ruminal tympany▪GDV▪Grain overloadG t i l▪Gastric ulcers▪Intestinal obstructions▪Enteritis & diarrheaEnteritis & diarrhea ▪Neonatal diarrhea▪Diarrhea in adults▪Peritonitis and abdominal fat necrosis
Alimentary systemAlimentary system
• Diseases are commonDiseases are common • Diagnostic procedures include
Cli i l d U/S l– Clinical exam –endoscopy, U/S, laparoscopy– Biopsy– Fecal exam– Necropsy & histopathology– Other lab tests
Portals of entry of pathogens
• Ingestion (most common)C &• Coughed up & swallowed
▪ Direct exposure to environmentp▪ Management/husbandry factors▪ Contamination of feed and water▪ Contamination of feed and water▪ Loose suspension in abdomen
Protective MechanismsProtective Mechanisms
▪ Endogenous secretions ▪ Resident flora and fauna▪ Resident flora and fauna▪ Vomiting▪ Increased peristalsis & diarrhea ▪ Rapid epithelial turnoverRapid epithelial turnover▪ Local immune response
degeneration vesicles bullae erosionsdegeneration vesicles bullae erosions ulcers cellular infiltration▪ Lesions in stratified epithelium▪ Lesions in stratified epithelium▪ No viral inclusion bodies
Ballooning degeneration of acanthocytes leading to vesicle (V) formation
Pemphigus vulgaris. Suprabasal separation due to loss of cell-to-cell adhesion
(acantholysis)
Direct immunofluorescence. There is deposition of immunoglobulin along the plasma membranes of epidermal keratinocytes in a fishnet-like pattern.
Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 28 October 2008 06:40 PM)
Foot and Mouth DiseaseFoot and Mouth DiseaseFMD, Aphthous fever
(Most dreaded animal disease in the world)( )
▪ Caused by a picornavirus (7 antigenic types)y p ( g yp )▪ Affects mainly ruminants and pigs▪ Transmission by ingestion and by inhalationy g y▪ Infection of pharynx leads to viremia and widespread localization in epidermal sitesp p▪ Lesions only in sites subjected to mechanical injury▪ Clinical signs: drooling saliva, lameness, etc.g g▪ Highly contagious, high morbidity, low mortality except in neonates
FMD LesionsFMD Lesions▪ Mucosal hyperemia, vesicles/bullae on lips, oral mucosa, feet and teats.▪ Vesicles/bullae rupture erosions/ulcersp▪ Scab formation & scarification▪ Myocardial degeneration & myocarditis inMyocardial degeneration & myocarditis in
• Caused by specific & nonspecific agentsnonspecific agents– Erosions & ulcers in
stratified squamousUlcerative stomatitis, uremia
stratified squamous epithelium
Oral ulcer, histo. Epithelial loss extendsbelow basement membrane to submucosa
Erosive & Ulcerative StomatitidesErosive & Ulcerative StomatitidesSome specific diseases/conditions
▪ BVD/MD ▪ MCF▪ Rinderpest ▪ Peste des petits ruminants▪ Bluetongue▪ Herpesvirus in cats, horses, primates▪ Feline calicivirus
i
Uremic ulcer, dog
▪ Uremia
Sharp, discrete erosions & ulcers, BVD
Sharp discrete erosions & ulcers, MCF
U i l dUremic ulcers, dog
FMD ulcer with epithelial flap
Uremic StomatitisPathogenesis & Lesions
▪ PathogenesisPathogenesis▪ High blood & salivary urea bacterial infection
high ammonia caustic injuryhigh ammonia caustic injury▪ High serum blood urea nitrogen vascular damage thrombosis ischemia infarctiondamage thrombosis ischemia infarction▪ Increased urea decreased immune response▪ LesionsLesions▪ Ulcers most often near salivary ducts, around teeth with plaques & ventral surface of tongueteeth with plaques & ventral surface of tongue
(Affected animals often have ammoniacal odor to the breath).