Bovine Viral Enteritis PDF

VIRAL ENTERITIS  BOVINE 1) Rotavirus (1-2 weeks old) 2) Coronavirus(calves < 3 weeks old) 3) Pestivirus(BVD) 4) Rinderpest 5) Malignant catarrhal fever (MCF) Rinderpest cattle plague A highly contagious viral disease of cattle that produces high morbidit...

VIRAL ENTERITIS  BOVINE 1) Rotavirus (1-2 weeks old) 2) Coronavirus(calves < 3 weeks old) 3) Pestivirus(BVD) 4) Rinderpest 5) Malignant catarrhal fever (MCF) Rinderpest cattle plague A highly contagious viral disease of cattle that produces high morbidity and mortality  Family: Paramyxoviridae,  Genus: morbillivirus (RNA)  High fever with anorexia.  Decreased milk yield.  Nasal/ocular mucopurulent discharge  Severe bloody diarrhea.  Dehydration  Shock, death  Gross Findings Focal erosions and ulcers of the upper GI Hemorrhagic, necrotic, edematous Peyer’s patches Hemorrhage and congestion of cecum, colon, rectum (zebra stripes) PEYER'S PATCHES specialized lymphoid aggregates in submucosa of the ileum.  Microscopic Findings  Lymphoid necrosis  Necrosis of intestinal crypts  Syncytia  intracytoplasmic & intranuclear inclusion bodies  Differential Diagnosis For gastrointestinal ulceration in bovines: Bovine viral diarrhea/mucosal disease : Linear esophageal ulcers Malignant catarrhal fever : conjunctivitis and corneal edema+necrotizing vasculitis Infectious bovine rhinotracheitis eosinophilic intranuclear inclusions Foot-and-mouth disease Vesicles, affects coronary bands and interdigital areas. Bluetongue disease: For diarrhea in bovines: Salmonella sp. Johne's disease Coccidiosis  Comparative Pathology Other morbilliviral diseases: Peste-des-petits-ruminants Canine distemper Measles Phocine distemper Acute, highly contagious, worldwide disease of cattle Family: Flaviviridae, Genus: Pestivirus  High morbidity and mortality fever  Diarrhea  Pneumonia.  Epidemiology depends on persistent infection (PI)  Gross Findings Erosions and ulcerations of GI Linear esophageal ulcerations Peyer's patches swollen, necrohemorrhagic  Infection at: 1. 50-100 days gestation: Fetal death, abortion, mummification 2. 100-150 days gestation: Congenital defects such as cerebellar hypoplasia 3. 150-200 days of gestation: Bovine fetuses become immunocompetent 4. Infection prior to 125 days of gestation with NCP strain: If the calf survives, it may develop persistent infection (PI)  Rotavirus and Coronavirus  Common causes for calf diarrhea  Attack the villi of the small intestine  Rotavirus (1-2 weeks old)  Coronavirus(calves < 3 weeks old)  Often detected in association with each other and other diarrhea pathogens, like Cryptosporidium  fluid-filled intestines profuse watery diarrhea Histologically: there is villus atrophy.  OVINE 1) Blue Tongue 2) Pest des Petite Ruminants A non-contagious viral disease transmitted with Culicoides Reoviridae family, orbivirus genus Sheep are the most susceptible species goats, cattle are susceptible  Gross Findings ULCERATIONS, AND CRUST OF THE SKIN, MUCOSA OF ORAL AND NASAL CAVITY Edema and cyanosis of the tongue Laminitis and coronitis  Hemorrhage in the tunica media at the base of the pulmonary artery (Pathognomonic)  Congenital anomalies (Hydranencephaly)  Abortion  Comparative Pathology Other common Orbiviruses: African horse sickness virus  Peste des Petits Ruminants (PPR) A viral disease (Morbillivirus) of goats and sheep characterized  Oculonasal discharge Pneumonia (bronchointerstitial) Syncytia: Multinucleated cell Stomatitis Linear Hemorrhages Intracytoplasmic / intranuclear inclusions Diarrhea  FELINE 1) Feline panleukopenia 2) Feline infectious peritonitis  Feline panleukopenia  Parvovirus  Young cats  Rapidly dividing cells in intestine, bone marrow & lymphoid organs Crypt necrosis & loss, villous atrophy Intranuclear Hyperemia and hemorrhage of intestinal wall inclusions cerebellarhypoplasia  Feline infectious peritonitis  Mutated enteric Coronavirus infection  Multisystemic disease  2 forms: Wet from (effusive) // Dry form (pyogranulomas) multiple white nodules (pyogranulomas) on the Serofibrinous peritonitis & pleuritis serosal surface of the small intestine  CANINE 1- Canine parvovirus enteritis (CPV-2) Similar to feline disease Interstitial myocarditis in puppies (rare) 2- Canine distemper Morbillivirus (enteritis , encephalitis, Pneumoina) BACTERIAL ENTERITIS COLIBACILLOSIS  Gram-negative bacteria  Non-virulant strains are considered normal flora  Most common cause of neonatal diarrhea in calves and pigs Enterotoxigenic E. coli (ETEC): Ingestion of virulent bacteria > adherence to small intestinal enterocytes > toxin production > diarrhea Diarrhea in neonatal pigs, calves, lambs (2,500) serovars/serotypes Nomenclature: (e.g. Salmonella enterica subsp enterica serotype Typhimurium) (shortened to Salmonella Typhimurium)  Highly host-adapted serotypes systemic disease (septicemia) in all ages of animal (e.g. Dublin in cattle, S. Cholerasuis in swine) Non host adapted (S. Typhimurium) enterocolitis (young animals) Serotypes that invade enterocytes have the ability to survive and replicate within macrophages An important zoonosis world-wide  Feco-oral route of transmission  Disease Forms: Septicemic Acute Enteric Chronic Enteric  Most animals are symptomless carriers  Stressors and/or diseases that compromise immune competence or disrupt the enteric bacterial ecosystem are often implicated in salmonellosis Cattle  S. Typhimurium, S. Dublin  common in newborn calves (usually more than one week old) Fibrinonecrotic (diphtheritic) enteritis the ileal mucosa was coated by a yellow fibrinous membrane (diphtheritic membrane).  Fibrinous cholecystitis (inflammation of the gall bladder) The wall of the gallbladder was thickened by edema; the lumen was distended by a fibrin clot Multifocal hepatitis (paratyphoid nodules)  Enterotoxemia Group of diseases caused by Clostridium perfringens Characterized by: 1. Sudden death in well-nourished animals 2. Necrotizing/hemorrhagic enterocolitis& toxemia Gram positive, sporulating, anaerobic bacillus 5 strains (A-E) based on production of 4 major lethal exotoxins, (alpha, beta, epsilon, and iota) Epsilon toxin (ETX) is the third most potent clostridial toxin (after botulinum and tetanus toxins) C. Haemolyticum Types of Clostridium perfringens  A: alpha toxin Yellow lamb disease  B: alpha toxin, beta toxin, and epsilon toxin Lamb dysentery  C: alpha toxin and beta toxin Bloody diarrhea in neonates Struck in adults  D: alpha toxin and epsilon toxin Pulpy kidney disease in lambs  Lamb Dysentery An acute disease of lambs