Calf Diarrhoea Flashcards
What are the causes of hyper secretory diarrhoea in calves?
ETEC e.coli
Calves under 5do
What is the cause of malabsorptive (osmotic diarrhoea) in calves?
Rotavirus, Coronavirus, BVD
Campylobacter, salmonella, clostridium
Cryptosporidium, coccidiosis
Calves over 6do
How can you make your own isotonic saline containing potassium and bicarbonate for use in a mildly acidosis calf?
5L H2O
34g NaCl
15g bicarbonate
5-8g KCl
Hartmanns is not indicated - expensive and contains bicarbonate precursors
- causes a dilutional acidosis
What is the best antibiotic for calf scour?
Amoxicillin
How can you make fluids for a severely acidotic calf?
5 H2O plus 45-60g NaCL
Then spike with
- 17.5g bicarbonate in 400ml for dairy
- 35g bicarbonate in 400ml for beef
What fluid rate should you start with in an acidotic calf?
80ml/kg/h - to give 2-3L in the first 45 mins
Maintenance = 10-20 ml/kg/h
At what age does VTEC/EPEC E.coli cause severe haemorrhagic scour?
18-21 days
At what age does Coronavirus and rotavirus cause scour in calves?
7-14 days
At what age does cryptosporidium cause scour in calves?
1-21 days
What TP cut off is a FPT?
<55 g/L
At what age does IgA and IgG stop being secreted into the gut?
7
What can you treat cryptosporidium with?
Halocur
What is w most important antibody for protecting again septicaemia?
IgM
What so the most common cause of calf diarrhoea?
Rotavirus
What are the sources of infectious agents in calf diarrhoea?
Adult cows
Other calves - pathogen multiplers
Diarrhoeic calves
Environment
What are the host defences in calf diarrhoea?
Passive immunity - IgA IgG - resecretion of IgM in the gut offers protection for 7d
Healthy gut flora
Healthy mucosa - nutrition
*if colostrum is not provided even following successful passive transfer the calf will develop diarrhoea due to lack of guy protection
What enviornmental factors influence the risk of calf diarrhoea?
Age in relation to calving period - young calves at high risk Stocking density - more contamination Indoors - pathogens can build up Group housing - easier disease transfer Hygiene - utensils - calving area
What 3 area should you direct management at in calf diarrhoea?
Hygiene
Improving calf immunity
Reducing predisposing factors - good housing, temperature and humidity, reducing stressors
What complication may predispose a calf to FPT and via reduced colostrum intake?
Dystocia
Calf born with respiratory acidosis - reduced colostrum intake
How can you minimise calf exposure to causative agents?
Clean calving area Remove calf after 2-4h Transfer into clean calf housing Individual calf housing best Ensure good hygiene at feeding Hospitalise sick calves
In beef systems
- use the Sandhills system - ensure no more than 2 week age spread between group of calves
- hospitalise sick calves
How can you maximise the protection to calves?
Dairy
- 4L colostrum in the first 6h of life, and again in next 6h
- continued colostrum feeding for 7days
Beef
- ensure good dam nutrition 3w pre calving
- frozen colostrum at bad calving
- vaccinate dam against rotavirus
What vaccinations are available to give the dam to protect the calf?
Enterotoxigenic E.coli
Rotavirus
Coronavirus
Must be given 30day before calving
Must continue to feed colostrum for 21days to provide protection
Describe the Sandhills system in beef farming
Every week you move the non-calved cows
This prevents the younger calves coming into contact with older calves and ensures an age spread of less than two weeks
Sandhills procedure is not very practical in the UK. Describe the system used in beef systems in the UK.
If the cows calves inside, turn out as soon as possible
Cow calf pairs are segregated in age groups with no more than a 7-10day age spread
Calves are mixed when the youngest child calf is 4 weeks of age
Coccidiosis in calves.
Seen in calves over 21 days
Due to poor hygiene - particularly around troughs
CP - dark scour +/- blood, tenesmus, BAR
Dx - faecal oocyst count
Tx - sulfonamides, vecoxan (coccidiostats)
Necrotic enteritis.
2-6mo
Sporadic, usually fatal
Unknown cause - poss vit E and selenium deficiency
CP: Pyrexia, pale mm, necrotic gut lesions
Dx: necrotic gut lesions on PME, thrombocytopaenia, leucocytopaenia
Tx: none usually fatal
Appears similar to BVD, necrotic lesions in gut and resp tract
Peri-weaning scour syndrome
Not fed enough concentrates pre-weaning =
under developed rumen
CP: pasty scour, bloat and poor growth at weaning
What mortality levels should a dairy farmer aim for?
Less than 5%
What what age should a dairy calf be weaned?
80kg (over 65kg) at at least 8 weeks old
- ideally wean at 10-12 weeks old
When eating 1.5kg of concentrates per day
Most farms wean at 2 months
What weight should a dairy calf be at 1st service - 13-14 months?
Over 380kg (ideally 400) 60% mature weight
What is the daily live weight gain?
0.9 kg/day
What are the benefits of good nutrition in the first 5 weeks of life?
Higher daily live weight gain
Lower age at conception
Lower % to be culled at the end of the first lactation
Increased total milk yield in the 1st and 2nd lactation
How can the traditional feeding regime be improved?
2L each feed, 2x a day, wean at 2m
Wean at a 10-12w
Acidified ad lib milk feeding or machine feeding
BASICALLY AD LIB CALF FEEDING AND WEANING AT 10-12 WEEKS THE BEST IN THE LONG TERM
How can twice daily bucket feeding be improved?
Designed to provide for maintenance only -
no provision for growth
Encourage early transition on to solid feed stuffs to promote early rumen development and early weaning
What are the benefits of individual housing?
Calf can pick their own environment if a hutch is available
Isolated so reduces the spread of infection
Must ensure good ventilation and drainage
Highly labour intensive
Reduced growth rates
What are the benefits of group housing?
Better growth rates and welfare
But increased disease
High standards of management required to maintain adequate hygiene
In the 1st 14 days of a calf’s life, what is the LCT?
15-20C
Below this - uses energy to keep warm
= less energy for growth + less energy for the immune system
How can you help keep calves warm?
Calf coat
Thick dry straw
Increase nutrition during cold periods
- 50% extra at 0c!!
What are the rules of group housing?
8 calves maximum
14 day maximum age spread
What is the maintenance requirement at weaning?
11 MJ/kg (65 kg)
Give lots of cake - encourages rumen development
What is the maintenance requirement at puberty?
9 MJ/kg
Hay/straw given ad lib
What target weight, height and BCS should a dairy heifer be at first service?
380-400kg
125cm withers height
2.5-3 BCS
Need a 0.9 kg/day DLWG to achieve this
What is the pathophysiology of calf diarrhoea?
Dehydration / hypovolaemia = pre-renal azotaemia
Metabolic acidosis - loss of HCO3-, lactic acid from muscles and colonic fermentation
Hyperkalaemia - H+ taken into cells and exchanged for K+
Hypoglycaemia
What are the signs of a calf being 5-7% dehydrated?
Reduced skin elasticity
Cold nose
Slight sinking of the eye
What are the signs of a calf being 7-10%
Sunken eye
Cold extremities
Skin tent
Weak or collapsed
What are the signs of a calf being over 10% dehydrated?
Collapsed, progressive shock
How can you diagnose metabolic acidosis in farm animals?
Blood gas machine - unlikely you would have this on farm
pH meter
Indications of fluid therapy in a calf
Calf unable to stand
Severely acidotic
Fail to improve after oral rehydration
Severely dehydrated even if standing
What fluids should you use to expand the calf’s blood volume?
Isotonic hartmanns solution
- Na+ 140mmol/L
- Bicarbonate 25-30mmol/L
- k+ 4mmol/L
Need to spike this with NaHCO3 in acidotic calves (bicarbonate)
- care - calves can’t metabolise all of the lactate to bicarbonate, therefore to need to spike with bicarbonate to prevent causing a dilutional acidosis
What volume of isotonic fluids should you give to a calf?
10-20 L
Including 5 litres of hartmanns spike with NaHCO3
- 200 mmol/L for a dairy calf
- 400 mmol/L for a beef calf
How can you expand the blood volume in calves?
10 ml/kg of 7.2% NaCl as an IV bolus
Make sure that you follow this up with water orally
What are the risks of IVFT?
Thrombophlebitis Overshoot alkalosis Acidification of the CSF Hypocalcaemia Alkalinisation of the CSF in an endotoxic calf
What size IV Catheters should you use in a calf?
14g 3 inch - jugular
18g - ear vein
What are 1st generation fluids?
Just correct dehydration
Include glucose to increase Na+ transport
What are 2nd generation fluids?
To correct dehydration and acidosis
Contain bicarbonate
And contain glucose to increase Na+ transport
What are 3rd generation oral fluids?
Contain glucose to address nutritional needs
What are 4th generation oral fluids?
Contain glutamine to aid villus repair
How much Na+ must oral fluids contain to be rehydrating?
120-130 mmol/L
How much bicarbonate should an oral fluid contain to correct acidosis?
25-30mmol/L
How should oral fluids be administered?
4-8L per day As soon as the scour starts Use a clean teat and bucket Give little and often Feed milk too
What disease is caused by dystocia in the calf?
Oedema, bruising, fractures
Hypoxia
Metabolic acidosis
Severe respiratory acidosis
How can you assess acidosis in a new born calf?
In sternal in less than 5 minutes - normal
More than 9 minutes = increased risk of death
How should you resuscitate a calf if it is not breathing after delivery?
Intubate 7-9.5 ET tube
Put in sternal
Ventilate with ambubag or blow down tube
50ml of 8.4% NaHCO3 IV
What antibodies are secreted into the gut to protect against scour?
IgA and IgG1
Offers protection for 5-10 days
What factors cause insufficient colostrum intake?
Heifers have less colostrum that is more dilute
High yielding dairy cows produce dilute colostrum
Acidotic calves do not suck
Holsteins have poor mothering abilities
Big teats are difficult for the calf to reach
What factors affect the colostrum quality?
When colostrum is collected in relation to calving Breed of cow Parity Pre-partum nutrition Length of the dry period Pre-milking Abortion Induction Mastitis
When is the best colostrum collected?
Immediately post partum = medical colostrum
What factors affect colostrum intake?
Inadequate supply - quality or quantity Poor udder / teat conformation Poor mothering ability Maternal disease - mastitis Poor calf vigour and ability to suck - acidosis
How long should it take for a calf to start sucking?
Less than 6h
Ideally less than 2
Best less than 1
What factors affect colostrum absorption?
Increased time from birth to sucking
Method of administration
Acidosis reduces absorption
Induction of parturition - reduced absorption
What immunoglobulins protect against septicaemia?
IgG
IgA
What parameters indicate adequate passive transfer?
Total proteins >55g/L
Zinc sulphate turbidity test >20 units
Measure from 48h-10 days old
How can you assess colostrum quality?
Brix refractometer - cut off 22%
Colostrometer
How can you prevent a failure of passive transfer?
Good cow nutrition pre-calving Avoid dystocia Tube feed 4L of colostrum within 6h Supervise Frozen colostrum
What is the best colostrum protocol?
Remove from calf from dam within 2h
4L colostrum in 1st 6h
4L in the next 6h
Feed tonic colostrum for the next 3-5 days
Continue colostrum harvesting and storing at 4c
Ensure feeding utensils are kept clean
Clean and disinfect teats before colostrum collection
Freeze colostrum from the first milking only, from low risk cows
What temperature and time should colostrum be pasteurised for?
60mins at 65c
What tissue of the umbilicus is most commonly infected?
Urachus
The infection of what tissues of the umbilicus results in the poorest prognosis?
Umbilical vein - goes to liver and creates abscesses
What does pitting oedema suggest?
Urolithiasis and rupture
What other investigations (on top of probing, reduction and US) should you perform in umbilical swellings?
Paracentesis - if you suspect peritonitis
Plasma total protein / zinc sulphate turbidity test
Differential white cell count
Fibrinogen - indicator of chronic inflammation
If the hernia is less than 1 finger in diameter what would you recommend?
Leave it alone
What after care does a calf need following a hernia repair?
Minimum of 1 month box rest
Do not turn out for 3 months
Mix with smaller animals to avoid bullying
How should you repair a calf hernia?
Xylazine premed 2 line blocks with procaine GA Make an elliptical incision and dissect hernial sac Use vicryl to close
