Inf. diseases II - Ruminant diarrhea & repro. 1/2 Flashcards
Winter dysentery is a highly contagious disease of adult cattle, caused by Coronavirus, and characterized by
an acute onset of a short course of severe diarrhea and sometimes dysentery.
Causative agent of Winter dysentery.
family
genus
dna type
Agent: Bovine coronavirus (BCoV)
Family Coronaviridae
Genus Coronavirus
RNA virus, single-stranded
Survival of BCV in environment.
Bovine coronavirus
Survives best at low temperatures and at low UV light intensities
Host range and age demographic of BCV
Bovine coronavirus
Affects mainly adults – most severely adult lactating cows that have recently calved
In humans: not
Seasonality of Bovine coronavirus
More common during winter months and in Northern climates
Typical outbreak lasts for 1-2 weeks
Morbidity of BCV.
Morbidity – high in affected herds
20-50% within few days, close to 100% within a week
Mortality of BCV.
Mortality – low: 1-2%
Transmission of BCV
Excretion: feces, respiratory excretions
Ingestion
Indirect contact
Fomites
Route: fecal-oral
IP: of BCV
IP: 3-7 days
Clinical signs of Winter dysentery
Acute onset of fluid diarrhea (Liquid and homogenous feces with little odor, green to black; May contain blood or mucus)
Profound decrease in milk production (25-95% production loss).
Mild colic
Dehydration
Depression
Brief period of anorexia
Some decrease in body condition
Post mortem signs of Winter dysentery
Lesions in large intestines:
Cecal and colonic mucosal hyperemia
Linear streaks or pinpoint-sized hemorrhages mostly along the colonic mucosal ridges
Blood in the lumen
Small intestine may be dilated and flaccid
MAterial for diagnosis of BCV. (3)
Feces
Blood
Colon, cecum
LAb analyses for BCV. (3)
Serology (ELISA)
RT-PCR
Histology
Tx of BCV
control of it?
Tx: no specific Tx since the course of dz is short
Fluids, electrolytes
Control dz with Biosecurity, good hygiene
Calf diarrhea caused by bovine corona virus
1 day to 3 month-olds
(most often 1-2 week-olds)
Virus is widespread
More common during winter months
Transmission route: alimentary or respiratory
Excretion: feces, respiratory secretions and tears
Source of transmission can be adult cows!
Diarrhea and dehydration
Sometimes respiratory illness (mostly mild)
Prevention: colostrum (antibodies)!
Calves not fed with colostrum right after birth have more severe illness.
Rotavirus causes
viral diarrhea in calves, lambs and other animals.
Rotavirus family and dna type.
Family Reoviridae
RNA virus
Rotavirus Groups
A and B
A is most prevalent and clinically important
Host range of rotavirus
Age demographic?
Host range in animals: cattle, buffalo calves, lambs, foals, kids, pet animals
Espesh: Calves 1-3 weeks of age
Groups A to both humans and animals.
Zoonosis!
Morbidity of rotavirus.
Morbidity – variable:
5-10% then up to 50-80% (3rd year)
Mortality of rotavirus.
Mortality: 5-60%
Depends on colostral immunity etc.
Transmission of rotavirus.
Excretion: feces
Direct contact
Route: fecal-oral
Clinical signs of rotavirus.
Moderate depression
Dehydration
Often continue to suckle or drink milk
Diarrhea
Feces are voluminous, soft to liquid, often contain large amounts of mucus
Commonly persist 3 or more days