Neonatal Losses and Acute Undifferentiated Diarrhea Flashcards
(90 cards)
What % of beef calf crop is lost between pregnancy diagnosis and weaning?
- ~10%
- Up to 25% of calves in some herds
Top causes of calf mortality
- Dystocia
- Stillbirths
- Hypothermia
- Diarrhea***
- Respiratory disease
- All of these combined account for >60% of claf deaths
What are the four main mechanisms of diarrhea?
- Osmotic
- Inflammatory
- Secretory
- Decreased absorption
Osmotic causes of diarrhea
- Rotavirus, coronavirus (destroys crypts and tips), Breda virus, etc.
Inflammatory causes of diarrhea
- Salmonella, Clostridia, parasites
Secretory causes of diarrhea
- enteric viruses, E. coli, Salmonella
Decreased absorption causes of idarrhea
- Protozoa, parasites, entericc viruses
Why is a lot of calf diarrhea “undifferentiated” diarrhea?
- Large number of pathogens and risk factors
- Etiologic diagnosis is NOT essential to successful Rx
Which etiologies can cause calf diarrhea in the first few days of life?
- E. coli (first couple of days)
- +/- Campylobacter
Which etiologies can cause diarrhea in the first couple of weeks?
- Cryptosporidiosis (5-35 days)*
- Clostridial (5-10 days)
- Salmonella (2-6 weeks)
- Rotavirus*
- Coronavirus*
- +/- Campylobacter
Which agents can cause diarrhea after 3 weeks?
- Coccidiosis (PPP is 18-21 days)
- Coronavirus
- Salmonella
- Cryptosporidiosis up to about a month
- CLostridial
PPP of Coccidiosis
- 18-21 days
- Can’t be in a calf that is a week of age
What is the major cause of diarrhea in calves <4 days
- E coli
E coli etiologies
- Hundreds of types (groups)
- Grouped based on virulence factors, pathogenic capabilities, and resultant clinical disease
What is the primary group of E. coli that impacts calves?
- Enterotoxigenic (ETC)
EHEC
- Enterohemorrhagic
- Attaching and effacing plus shiga-like toxin
EPEC
- Enteropathogenic
- Attaching and effacing (AEEC)
IEC
- Invasive E coli
Are all forms of E coli pathogenic to all species?
- NOPE
What are the primary virulence factors of E. coli?
- Fimbrial antigens (K99, F41)
- Shigatoxin a
Role of the fimbrial antigens?
- Attachment –> colonization and multiplication
Role of shigatoxin a
- Secretory diarrhea
- Increase bicarbonate and Cl secretion
- Decrease sodium resorption
On which operations do we tend to see salmonella as a problem?
- Primarily intensive operations
- Dairy > beef
Serotypes of Salmonella
- There are a lot