Calf Diarrhoea Complex

Calf Diarrhoea Complex

1. AETIOLOGY

   • Multifactoral
     • CALF
     • ENVIRONMENT
       • Poor housing/hygiene Overcrowding Mixing age groups Poor management of sick calves
     • NUTRITION
       • Inadequate colostrum Poor feeding hygiene and routines
     • INFECTIOUS AGENT
       • Most common: - Salmonella - E. coli - Rotavirus - Coronavirus - Cryptosporidium Often more than 1 agent present 

2. RISK FACTORS

   • Beef herds
     • Large herds
     • High stocking rates
     • Stagnant water
     • Mixing cows with heifers
     • Exposure to high-use calving areas
     • Dirty udders
     • No pasture rotation
   • Intensive rearing
     • Bad husbandry
       • Poor ventilation Moisture accumulation Draughts
     • Overcrowding
     • Mixing age groups
     • Poor nutrition
       • Bad milk replacer Variable milk temperature Contaminated milk 1 feed/day
     • Introducing externally-sourced calves
     • Male humans caring for calves

3. PATHOGENESIS

   • Osmosis of fluid into gut
     • E.coli enterotoxin Salmonella inflammation + damage Viral/protozoal epithelial destruction Hypovolaemic shock
     • Increased secretion
     • Reduced absorption
   • Reduced feeding
     • Changed intestinal flora
   • Dehydration + metabolic acidosis
     • Fluid loss
     • Electrolyte loss
       • Na Cl K Bicarbonate
   • Electrolyte abnormalities
     • Hyperkalaemia (moving extracellular) Hypoglycaemia

4. DIAGNOSIS

   • Faecal culture
     • Salmonella E.coli
   • FEC and faecal smear
     • Cryptosporidium
   • PAGE
     • Polyacrylamide gel electrophoresis Rotavirus
   • Calf-side tests
     • Rotavirus E.coli  Cryptosporidium
   • Sample taking
     • Multiple calves Faeces
   • Postmortem
     • Emaciation Non-specific signs of diarrhoea + dehydration Haemorrhagic enteritis - Salmonella, coccidia Intestinal swabs Histopathology --> Intestines, liver, spleen, LNs, lungs, joints

5. TREATMENT

   • Goals
     • Replace lost electrolytes + fluids
     • Nutritional support
     • Correct metabolic acidosis
     • Aid intestinal repair
     • Eliminate bacteraemia + reduce agent numbers
     • Correct hypothermia
   • FLUID THERAPY
     • GOALS
       • Support kidneys Correct Na/K imbalances Correct metabolic acidosis Provide energy
     • Assess dehydration
       • <5% = minimal eye recession, 2-4 second skin tent, moist MMs, warm extremities 8-12% = 4-7 mm eye recession, >8 second skin tent, dry MMs, cold extremities
       • Skin tenting
       • Sunken eyes
         • % dehydration = 1.7 x recession depth (mm)
       • Mucous membranes
       • Correct dehydration
         • Mild
           • PO fluids to correct deficit
             • E.g. 4% dehydrated in 45 kg calf = 45 x 0.05 = 2.25 L fluid
           • PO fluids for maintenance
             • 10% of bodyweight at 3 ml/kg/hour if IV E.g. 45 kg calf = 4.5 L 
           • Electrolytes
             • Sodium, glucose, bicarbonate, acetate/proprionate
           • Re-intro milk >3 hours after electrolytes
             • Give 2-4 L extra, 2+ feeds/day
           • Fluids for ongoing losses
         • Severe
           • Assess acidosis
             • How much bicarb needed (1.3% solution - 13 ml/L
             • <40 kg
               • &lt;8 days + recumbent = 2 L &gt;8 days + sternal = 2 L &gt;8 days + lateral = 3 L
             • >40 kg
               • &lt;8 days + recumbent = 3 L &gt;8 days + sternal = 3 L &gt;8 days + lateral = 4 L
           • 30-40 ml/kg/hour
             • BW x % dehydration Add 50 ml dextrose/litre Signs of improvement --&gt; urination, reduced dehydration, improved mentation, suckling reflex
           • Ongoing care
             • 3 ml/kg/hour maintenance
             • Warm dry environment
             • TLC
     • Assess base deficit
       • 5 mmol/L = BAR, strong suckle reflex, warm mouth 10 mmol/L = quiet, moves if disturbed, weak suckle, slight cold mouth 15 mmol/L = depressed, unable to stand, no suckle, cold mouth 20 mmol/L = collapsed, lateral recumbency, no suckle, cold-mouth, moribund&nbsp;
   • ANTIBIOTICS
     • Indications
       • Severe diarrhoea + dehydration True bacterial enteritis + septicaemia 2ndry infections in viral diarrhoea
     • Contraindications
       • Mild/moderate diarrhoea PER OS ADMIN
     • Options
       • TMS
       • Ceftiofur
       • Amoxicillin
       • Halofuginone lactate
         • Cryptosporidium prophylaxis + treatment

6. PREVENTION

   • GOALS
     • Good management
       • Hygiene Stocking density Pasture/pen rotation + spelling No mixing of age groups
     • Good quarantine + treatment
     • Prophylaxis
   • Good colostrum intake
     • Vaccinated dams
     • Good temperature
     • Feeding hygiene
     • Bottle feed if not getting enough
   • Boost immunity
     • Prepare the dam
       • Vaccination - rotavirus, ETEC, coronavirus Transitional feeding Supplementation
     • Colostrum feeding for 2-4 weeks
     • Reduce stressors
       • Dystocia navel ill Poor environment Mixing of age groups Overcrowding Poor nutrition
   • Reduce infectious load
     • GOOD BIOSECURITY
     • Hygiene
     • All-in, all-out
     • Paddock rotation
     • Prompt treatment + isolation
     • Reliable calf supplier
     • Clean feed and water

7. DISEASES

   • E.COLI
     • Syndromes
       • 1. Neonatal colibacillosis
         • Calves <4 days old
         • YELLOW WHITE diarrhoea
         • Enterotoxic E. coli
           • K99 antigen
           • F antigens adhere to mucosa
           • Heat stable toxin
             • Hypersecretory diarrhoea
       • 2. Diarrhoea + dysentery
         • Calves >6 weeks
         • EHEC
           • Villous atrophy + mucosa inflammation
           • Mucoid bloody diarrhoea
           • Bruxism
         • AEEC
           • Attaching and effacing E. coli
     • Diagnosis
       • Histopathology
         • Intestines
   • Salmonella
     • Aetiology
       • S. typhimurium
       • S. Dublin
     • SOURCES
       • Infected calves
       • Adult carriers
         • Shed when stressed
       • Fomites
       • Carrier calves
       • Humans
       • Wildlife
     • 8-10 day old calves
       • Requires overwhelming infection
     • Pathogenesis
       • Mucosal invasion = enteritis
         • Villi loss
           • Malabsorption + PLE
           • Bacteraemia
           • Haemorrhage + mucosal sloughing
     • Diagnosis
       • CS
         • Dysentery - mucoid + malodorous + mucosal shreds Abdominal pain
       • Postmortem
         • Haemorrhagic/catarrhal enteritis Mesenteric LN enlargment +/- cranial bronchopneumonia, liver pathology
   • Rotavirus
     • 1-2 week old calves
       • Reduced colostrum immunity Most common cause of calf diarrhoea
     • Pathogenesis
       • Often mixed infection
         • Cryptosporidium Salmonella E.coli
       • Transmitted by
         • Infected calves
           • Shed for up to 3 weeks
         • Carrier adults
         • Environmental survival
       • Activation by proteolytic enteric enzymes
         • Epithelial destruction
           • Upper intestines, then lower as progresses
           • Enterocyte losses
           • Villi atrophy
             • Malabsorption + maldigestion
         • Self-limited by cellular destruction
     • YELLOW-GREEN watery diarrhoea
     • Prevention
       • Vaccinate dams
       • Colostrum feeding
   • Cryptosporidium
     • Aetiology
       • C. parvum
         • Small intestine
       • C. muris
         • Abomasum
     • PPT 3-6 days
     • Pathogenesis
       • Invades + destroys enterocytes
         • Villous atrophy
           • Malabsorptive diarrhoea
             • Watery + yellowish
       • Concurrent infections
         • E. coli
         • BVD
         • Rotavirus and coronavirus
     • Zoonotic
     • 4 day-4 week old calves
       • Age resistance
       • Overcrowding
       • Poor hygiene
       • Highly used calf pens
         • Environmental resistance
   • Coronavirus
     • 1-3 week old calves
     • Sources
       • Environment
       • Infected calves
       • Adult carriers
     • Pathogenesis
       • CS
         • Profuse watery diarrhoea --&gt; Turns mucoid and contains undigested milk + blood
       • Severe enterocyte damage
         • Villous atrophy
         • Malabsorption
         • Hypersecretion
         • Attacks immature enterocytes
           • Prolonged recovery