Neonatal Losses and Acute Undifferentiated Diarrhea Flashcards
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
Who gets Salmonella?
- Neonate (4-28 days) to adults
Different manifestations of Salmonella
- Diarrhea vs septicemia
- Peracute to chronic
- Found dead –> fever/anorexia/dull –> diarrhea
- Profuse watery –> mucofibrinous/hemorrhagic
What are the three main types of Salmonella enterica
- S. Typhimurium
- S. Dublin
- S. Newport
S. Typhimurium - who gets?
- Calves <2 months
- Also one of the more common ones isolated in people
What is the multi-drug resistant form of S. typhimurium called?
- S. newport
S. dublin - who gets?
- ALL AGES
S. dublin characteristics of disease
- More invasive
- Meningitis/arthritis/physitis
- Respiratory disease, gangrene of distal limbs
- Chronic carriers**
Mechanisms of diarrhea with Salmonella
- Inflammation (hemorrhage, fibrin)
- Maldigestion/malabsorption
- Protein loss
Infection routes with Salmonella
- MANY
- Ocular
- Nasal
- Oral
- Udder
- Rectal
Excretion routes with Salmoneall
- FECES**
- Milk
- Urine
- Nasal and saliva
What are the primary neonatal GIT viruses?
- Rotavirus
- Coronavirus
- Torovirus
What other GIT viruses can cause problems?
- BVD
- Calicivirus
- Parvovirus
- Astrovirus
Where is rotavirus found?
- Ubiquitous
- 50-100% of farms and ranches
Stability of rotavirus
- Stable except in freezing temperatures
Ages of animals that tend to get rotavirus
- Calves <3 weeks, peak at 6 days
Incubation period of rotavirus
- 24 hours
What other diseases are common with Rotavirus?
- Concurrent E. coli and Cryptosporidia common
What part of the GIT does rotavirus affect?
- Implications for mechanism of diarrhea
- Affects mature, villous enterocytes (spares crypts)
- Villi don’t absorb, crypts continue secretion
- Malabsorption/maldigestion
Special protein with rotavirus
- NSP4 (nonstructural glycoprotein 4 enterotoxin)
What does NSP4 do?
- Decreases carbohydrate digestion
- Inhibits Na-Glucose co-transporters (facilitating water absorption)
Rotavirus treatment
Non-specific support
- Rehydrate to restore low osmolality + Na and glucose
How to prevent rotavirus?
- MANAGEMENT IS THE CURE!
Aspects of management that are important with rotavirus
- Housing, hygiene, colostrum, cow vaccines
Where is coronavirus?
- Ubiquitous (50-100%)
Stability of coronavirus
- Also stable except in freezing temperratures
Route of transmission of coronavirus
- Oral OR respiratory infection
Who gets coronaviral diarrhea?
- Calves <3 weeks, peak at 7-10 days
- Incubation 48 hours
What parts of the GIT does coronavirus impact?
- Implications for mechanisms of diarrhea
- Villous AND crypt enterocytes
- Malabsorption/maldigestion diarrhea
- Longer duration - more tissues affected
Treatment of coronavirus
- Non-specific support
- Rehydrate - low osmolarity, Na and glucose
Prevention of coronavirus
- management (housing, hygiene, colostrum, cow vaccines)
Torovirus family
- Coronaviridae
Distribution of Torovirus
- WOrld-wide distribution
- 90% of cattle are exposed
Age of calves impacted by torovirus
- <30 days but range 2 days to 7 months
Where in the GIT does torovirus impact?
- Consequence for diarrhea
- Distal jejunum, ileum, colon
- Crypt and villi necrosis
- Villous atrophy
- Malabsorptive diarrhea
Other causes of neonatal diarrhea
- Cryptosporidia
- Giardia
- Clostridia
- Coccidia
Cryptosporidia - % in beef and dairy calves?
- 100% in dairy
- 5% in beef
Where are cryptosporidia oocysts?
- In the environment
Time frame of cryptosporidia
- Clinical in 3-5 days, shedding in 3 days lasts 4-17 days
Type of diarrhea with cryptosporidia?
- Severe villous atrophy –> malabsorption
Treatment of Cryptosporidia
- Equivocal or cost prohibitive
- Colostrum?
Vaccines for crypto?
- None validated
Age of animals with cryptosporidia?
- Usually 5-15 days old
Cryptosporidia sequela
- Usually self-limiting
Passive immunity against cryptosporidium
- Passive immunity does NOT protect against infection but DOES lessen disease
Is cryptosporidium zoonotic?
- Yes
Distribution of Giardia
- World-wide distribution
Significance of Giardia
- Cattle not as significant a source to humans as once believed
- Significance as cattle pathogen unclear, as it’s found in both normal and diarrheic calves
Which types of C. perfringens are most common in calves?
- Type C
- Type B and D occasionally
- Type A?
Age of most animals with C. perfringens
- Most cases under 2 weeks up to 3 months
What can lead to C. perfringens disease in older calves?
- High grain diet
- Change in diet
Age of animals with coccidiosis
- Calves >17-21 days old
What is the underlying cause of coccidiosis?
- MANAGEMENT
Appearance of animals with coccidiosis
- Blood tinged diarrhea
- Ill thrift and poor doers
3 Principals of prevention of acute undifferentiated diarrhea in calves
- Control the level of infection in the calf’s environment
- Increase calf non-specific resistance
- Increase calf specific immunity
REDUCE STRESS
How quickly can dirt become contaminated with disease?
< 2 weeks
How to control the environment in the calving pasture to prevent AUD?
- Minimize congregation
- Feed to promote dispersal (feed hay/grain distant from water; move bunks/bale feeders periodically; fall calving)
Which season of calving can promote dispersal?
- Fall calving
How to control the environment in the nursery pasture to prevent AUD?
- Identify stocking rates
- Have a quarantine pasture (Scours pasture) until branding
What aIn the nursery pasture, what’s the widest range that should be kept together?
<30 days between oldest and youngest calves
How to increase non-specific resistance?
- Assist birth if necessary to minimize stress
- Feed colostrum if no suckling within 2 hours
- Watch for mis-mothering
- Encourage bonding ASAP
- Monitor dystocia calves
How to increase specific immunity in calves?
- variable immunity to certain agents
- Previous exposure of the dam
- vaccination (don’t over-emphasize)
How important is vaccination for prevention of AUD?
- It’s relatively important, but don’t over-emphasize
- You can’t just vaccinate your way out of poor management
Vaccination for enteropathogens
- No vaccines are all-encompassing
- No vaccine will make up for inadequate management
How to reduce stress of cattle?
- Be thoughtful during inclement weather
- Poor ground surface conditions
- Crowding
Sandhills calving system
- Utilizes a series of calving pastures to minimize newborn calves’ contact with disease agents
- SCS recreates conditions of first week of calving during each of the remaining weeks of calving
- Clean calving area without older calves that may be shedding pathogens
- Create 8, 1 weeks seasons rather than one, eight-week season
Description of Sandhills Calving System
- Cows are turned into the first calving pasture as soon as the first calves are born, and calving continues for one to two weeks
- After 1-2 weeks calving in Pasture 2, cows not yet calved move to pasture 3
- Cow calf pairs born in pasture 2 remain in pasture 2
- With each subsequent 1-2 weeks, cows not yet calved are moved to an ew pasture
- Pairs remain in their pasture of birth
