123. Diseases of cattle caused by Escherichia coli. Flashcards
Coli septicemia of calves Occurence and Ethiology?
Coli septicemia of calves
- Occurrence: sporadic
- Etiology: septic (invasive) E. coli strains (O78:K80), F17
o No toxin production, colicin plasmid, survival in blood (siderophors, iron-binding proteins)
Epidemiology of Coli septicaemia in calves?
Epidemiology:
- first week of life,
- immediately afterbirth
o Predisposing factors:
- didn’t receive colostrum or low quality of colostrum - hypogammaglubbulinemia (agammaglobulinemia),
- navel infection (not disinfected, bacteria can reach
- the liver and spread
Pathogenesis of Coli Septicaemia in calves?
Pathogenesis:
- infection (PO, umbilical)
- > pharynx lymphoid tissues
- (=> blood) or gut (=> blood) > septicemia
- > bacteria will be lysed and release endotoxins
- = endotoxin effects (produce clinical signs)
Clinical signs of Coli septicaemia of Calves?
Clinical signs:
- not very typical, fever!!,
- anorexia,
- depression,
- weakness,
- diarrhea is NOT typical (sometimes can have diarrhea, but rare and in later phase if animal don’t die first),
- meningitis,
- pneumonia,
- dies within 1- 2 days
Pathology and diagnosis of Coli septicaemia in calves?
• Pathology:
- hemorrhages,
- enlarged LN and parenchymal organs,
- pericarditis,
- perihepatitis (fibrinous),
- peritonitis
• Diagnosis:
- epidemiology,
- clinical signs,
- PM lesions
- o Isolation of the agent from parenchymal organs,
- blood
Treatment and prevention of Coli septicaemia in calves?
Treatment:
- parenteral AB,
- generally too late when already see clinical signs from endotoxic effects
• Prevention:
- hygiene,
- colostrum in time and sufficient amount,
- optimal nutrition of pregnant cows,
- check the level of immunoglobulines in newborn calves,
- disinfection of the navel
Coli diarrhea of calves Occurence and ethiology?
Coli diarrhea of calves
• Occurrence:
- widespread,
- more frequent than the septicemia form
• Etiology:
- enterotoxigenic E. coli
- o Fimbria: F5, F17, F41
- o ST toxin production
- o Enterotoxin production
Epidemiology and pathogenesis of Coli diarrhea of calves?
Epidemiology:
- large scale farm,
- end of winter,
- 2-4 days old,
- colostrum (but can’t completely prevent, but milder), predisposing factors are needed
- (nutritional deficiency -
- usually end of winter,
- overcrowding,
- housing conditions)
• Pathogenesis: per os infection
- > colonization the gut and attach to epithelia,
- toxin production
- > decreased absorption and increased fluid in gut
- > fluid loss,
- diarrhea
Clinical signs and Pathology of Coli diarrhea?
Clinical signs:
- NO fever (usually toxin effects in gut only),
- anorexia,
- depression,
- diarrhea (yellow, stinking) see faeces stains around anus,
- strong dehydration,
- in case of sufficient colostrum supply - clinical signs are milder
• Pathology:
- exsiccosis (loss of fluid)
- stomach and gut filled,
- hyperemia can happen but NO inflammation
Diagnosis, DD, treatment and prevention of Coli diarrhea?
Diagnosis:
- epidemiology,
- clinical signs,
- PM
- o Isolation of agent:
- detection of virulence factors (fimbria, ST),
- serotyping
o Differential diagnosis:
- rotavirus (second week of life),
- coronavirus (2nd week old, have blood in feces- not bloody diarrhea),
- cryptosporidiosis (in older)
• Treatment:
PO AB,
rehydration
• Prevention:
- hygiene,
- disinfection,
- good nutition of pregnant cows,
- colostrum,
- isolation (individual cages - no fecal contamination, moving cages after weaning),
- vaccination in pregnant cows - 6 weeks before parturition
- (bacterins, inactivated toxin, combined vaccines)
Calf dysentery Occurence, ethiology?
Calf dysentery
- Occurrence: sporadic
- Etiology: Vertotoxigenic E. coli (VTEC/EHEC)
o VT1, VT2
o O157:H7, other types can also produce the disease
Epidemiology of calf dysentery?
Epidemiology:
- subclinical infection is common,
- shedding is common
- o Cows don’t show signs but are carrier 1-3%
- o Carriage by calves 5-15%
- o Public health importance = ZOONOTIC
Pathogenesis, clinical signs and pathology of Calf dysentery?
Pathogenesis:
- per os infection
- > small amount of bacteria is enough
- > replication in LI
- > damage microvilli
- >production of verotoxins (VT1, VT2) act on endothelia = hemorrhages
• Clinical signs:
- 2-8 weeks old,
- rarely,
- subclinical is common,
- chronic diarrhea (brownish, reddish, cream-like),
- can recover spontaneously, generally not fatal
• Pathology:
LI - hyperemia, hemorrhages
Diagnosis, DD and treatment of calf dysentery?
Diagnosis:
- bacterium isolation,
- serotyping
- Detection of toxin
o Differential diagnosis:
- coccidiosis,
- coronavirus (overlapping age, last untill end of 3rd week old, there’s more blood in VTEC),
- cryptosporidiosis
• Treatment:
- oral bacteriostatic AB (bactericide can help release the toxin),
- rehydration
- Mastitis
