Scouring in Calves

Question 1

How much can a single case of calf diarrhoea cost?

Answer 1

Around £40-50

Question 2

Why might it be difficult to get an accurate estimate of how calf diarrhoea there actually is?

Answer 2

• Inconsistent reporting
• Might not realise it actually is diarrhoea
• Subjectivity – farmers perceive things differently
• Calf care isn’t as important to some farmers as others and record keeping isn’t always that great

Question 3

What are some important points of the epidemiology of scour in calves?

Answer 3

• Infectious vs non-infectious
  
  • A lot of infectious
  • Non-infectious can be due to nutritional causes such as not mixing milk replacer, not regime in feeding times etc. – tends to be milder, but remember can be non-infectious
• Most agents ubiquitous/endemic
  
  • Mostly, not a disease of epidemiology
• Mixed infections very common
  
  • Relatively more common to see multiple agents all involved in infection rather than an outbreak cause
• Zoonotic implications
  
  • Always have this in mind when seeing individual calf, have it in might for yourself!
• Dairy/suckler
• Housed/outdoors

Question 4

According to 2016 VIDA, what are the most common diagnoses of specific agents in bovine neonatal diarrhoea?

Answer 4

• Salmonella left out as VLA don’t split adults/calves: would expect salmonella in calves to be similar level to coronavirus/e coli??
• Numbers look very similar for 2012
• A lot of infections mixed
• Big chunk for rotavirus and crypto
• Salmonella is missing from here as APHA labs don’t distinguish between adults and calves

Question 5

Which causal agenst of calf scour post the most zoonotic risk?

Answer 5

• Crypto biggest threat
• E.coli but K99 one in calves is rare to get contact zoonoses to people – more of a food borne one
• One not on the list – SALMONELLA
• Zoonotic via direct contact

Question 6

What influences the challenge of calf scour? Where does it come from?

Answer 6

• Sources of infection
  
  • Diseased animals – other calves with scour
  • Clinically normal carriers (often adults) that shed infection
• Pathogen “load” – how much of the bug the animal is exposed to is dependent on:
  
  • Hygiene/environment
  • Stocking density
  • Isolation of clinical cases
  • Separation from adults -

Question 7

What infleunces the calf defences?

Answer 7

• Colostrum status – very important!
• Stress and stocking density – if you overstock, dirties environment but also stresses the animals and alters immune function
• Intercurrent disease (e.g. BVD, respiratory disease)
• Correct feeding – underlying nutritional scour makes it easier for infections to happen
• Trace element status – ones important are vitamin E and selenium – these are the most important immune related ones
• epidemiology – slightly unusual disease syndrome in that mostly caused by infectious agents, but most agents are ubiquitous so really a disease “of management”

Question 8

What are the clinical signs of scour in calves?

Answer 8

Diarrhoea

• Colour/consistency varies
• But doesn’t often tell you much!
• “White” & pasty – E. coli or nutritional diarrhoea?
• White scour is a colloquial name for E.coli in some parts of the world
• Dark and/or bloody – coccidiosis or salmonellosis?

Dehydration

Acidosis

Question 9

If you have white and pasty scour, what is this indicative of?

Answer 9

• White” & pasty – E. coli or nutritional diarrhoea?
• White scour is a colloquial name for E.coli in some parts of the world

Question 10

If you have dark and/or bloody scour, what is this indicative of?

Answer 10

coccidiosis or salmonellosis

Question 11

What are some of the consequences of diarrhoea?

Answer 11

Can be either hypersecretory (only really ETEC) or malabsorptive (others, villous atrophy etc) but both lead to dehydration +/- acidosis

Acidosis -> hyperkalaemia d/t exchange of K for H ions across cell membrane

Question 12

What are the clinical signs you will see with the following percentages of dehydration:

1. 1-5%
2. 5-7%
3. 7-10%
4. >10%

Answer 12

1. Increased thirst
2. Skin tent

Slight sunken eye

Cold nose

3. Very sunken eye

Cold extremities

Weak/collapsed

4. Collapse

Progressive shock

Question 13

Acidosis is a clinical sign of scour, what do you see with acidosis?

Answer 13

• Signs not very specific – they can also happen with severe dehydration! Acidosis and severe dehydration overlap a lot in terms of their clinical signs!
• Poor/absent suck reflex
• Depressed/recumbent
• Comatose
• Increased respiratory rate
• Poor response to rehydration
• Common in calves >6d
  
  • Especially beef suckler calves, large muscles – people think its due to tissue perfusion – more lactic acid can build up due to the poor perfusion to the large masses of muscle

Question 14

What are the specific clinical signs of scour caused by Enterotoxigenic E.coli (ETEC)?

Answer 14

• Secrete a toxin that causes a lot of water to leak into the gut
• Watery diarrhoea in young calf (<6d)
• Rapid progression to collapse
• Usually sporadic (single case)
• Some similarities with “watery mouth” in lambs
  
  • Entry via GIT
  • Bacteraemia
  • Hygiene/colostrum important
  • D+ less common in lambs – but otherwise quite similar diseases

Question 15

How is Enterotoxigenic E.coli scour comparable to that of watery mouth in lambs?

Answer 15

• Some similarities with “watery mouth” in lambs
  
  • Entry via GIT
  • Bacteraemia
  • Hygiene/colostrum important
  • D+ less common in lambs – but otherwise quite similar diseases

Question 16

What are some specific clinical signs of scour caused by salmonellosis?

Answer 16

• Often bloody diarrhoea with pyrexia – other diarrhoeas usually aren’t pyrexic
• Can be pretty much any age
• Less endemic

Question 17

What are some specific clinical signs of scour caused by coccidiosis?

Answer 17

• Often less severe D+/systemic signs
• Sometimes darker, stiff faeces +/- blood
• Often tenesmus
• Usually peri-/post-weaning
• Some clues that cocci is cause – generally groups, usually milder d+ and less systemic signs, usually a bit older.
• Affects lower GI so stiffer D+ with dark blood

Question 18

What are the clinical signs of clostridial enterotoxaemia in LAMBS?

Answer 18

• Clostridial enterotoxaemia (“lamb dysentery”) – tends to be ACUTE onset, very young lamb disease, often just present with sudden death, signs previously often missed. Clostridial enterotoxaemia caused by Cl perfringens B/C, can ?also happen in cattle but very rare
  
  • Very acute onset, usually <2wks old
  • Often sudden death
  • Abdominal pain, bloody scour
  • Localised haemorrhagic lesions on post mortem

Question 19

When is making a diagnosis about the causal agent of the scour important?

Answer 19

• Treatment decisions
• Prevention strategies
• Zoonotic risks – wise to consider these whether you think crypto is present or not! Management still the same
• Don’t often need to know the actual bug to know how to prevent it – its usually colostrum and environmental cleaning

Question 20

Is it worth diagnosing the causal agent of the scour in calves?

Answer 20

• Maybe if vaccination is being considered
  
  • (although vaccines multivalent and pathogens ubiquitous/mixed infections common)
• If there are specific treatments for specific agents…
  
  • E coli (antibiotics useful)? – clinical picture useful
  • Salmonellosis (antibiotics useful)
  • Coccidiosis? – clinical picture useful
  • Crypto – although can usually control without specific treatment
• Can be very expensive and may not get a useful result

Question 21

Which scenario fits best with diarrhoea caused by ETEC (enterotoxigenic E.coli):

A.Group of 10d old, moderately dehydrated scouring calves

B.Individual 2d old collapsed calf with watery scour and subnormal temp

C.Group of 5wk old calves with pyrexia and bloody scour

D.Group of 8wk old calves with dark, slightly bloody scour and tenesmus

Answer 21

B.Individual 2d old collapsed calf with watery scour and subnormal temp

Question 22

Which scenario fits best with diarrhoea caused by salmonellosis?

A.Group of 10d old, moderately dehydrated scouring calves

B.Individual 2d old collapsed calf with watery scour and subnormal temp

C.Group of 5wk old calves with pyrexia and bloody scour

D.Group of 8wk old calves with dark, slightly bloody scour and tenesmus

Answer 22

C.Group of 5wk old calves with pyrexia and bloody scour

Question 23

If you want to try and diagnose the cause of an outbreak, how can you do this?

Answer 23

• Post mortem examination (VLA)
  
  • Ideally early in course of disease
• Faecal sampling – take several samples from a group to help
  
  • Viral antigen (rota/coronavirus)
  • Parasitology (crypto/cocci)
  • Culture (Salmonella spp/E. coli)

Question 24

What is the main thing to consider when treating a calf scour?

Answer 24

• Remember: most causes self-limiting
  
  • Supportive therapy is usually the most important
• Correcting dehydration and acid-base balance

Question 25

What are the 2 basic choices for fluid therapy if it is indicated and decided for a calf scour?

Answer 25

Oral

• Quick, easy, farmer can perform
• BUT can be dangerous if calf very weak
• Don’t stomach tube a calf if it cant keep its head up

Intravenous

• Safe if calf is very weak, collapsed, more rapid effect, can be more precise
• BUT more time consuming and requires some level of skill aswell

Question 26

Name the 1st generation to the 4th generation of oral rehydration therapy

Answer 26

• 1st generation
  
  • Na/K/and small amount of Glu e.g. Lectade, Pfizer
• 2nd generation
  
  • Na/K/small amount of Glu/HCO3, e.g. LifeAid Xtra, Norbrook
• 3rd generation
  
  • Na/K/­increased amount of Glu/HCO3, e.g. Energaid, Elanco
• 4th generation
  
  • Na/K/ increased amount of ­Glu/HCO3/Glutamine, e.g. Glutalyte, Norbrook
• Gels (similar content)
  
  • Add to milk e.g. Rehydion, CEVA

Question 27

What is the difference is commercial vs DIY IV fluid therapy?

Answer 27

• Usually need to add HCO3 to commercial otherwise acidogenic!
  
  • Limited ability to process lactate –> HCO3
  • Care – adding HCO3 can ppt out Ca salts in Hartmans
• Can generally safely use home-made fluids
  
  • Tap or distilled water + salt +/- bicarbonate

Question 28

What are the specific treatments for scour caused by E.coli (ETEC)?

Answer 28

• Systemic antibiotics (bacteraemia/toxaemic) e.g. Cephalosporins, amoxycillin, florfenicol
• NSAIDs?

Question 29

What are the specific treatments for scour caused by Salmonellosis?

Answer 29

• Systemic antibiotics (some debate but on balance usually used) e.g. Potentiated sulphonamides, potentiated amoxycillin – a wide range
• Antibiotic resistance relatively common

Question 30

What are the specific treatments for scour caused by coccidiosis?

Answer 30

• Diclazuril and toltrazuril – both preventative things, oral drenches
  
  • Licensed for prevention
  • Commonly used to treat clinical cases as well (nothing licensed for treatment)
  • Oral drench
• Decoquinate
  • Used for prevention
  • Feed additive (fed in concentrate)
  • Should be able to sort with hygiene though! But can be short term whilst you figure other stuff out, like how to reduce stocking density etc.

Question 31

What are the specific treatments for scour caused by cryptosporidiosis?

Answer 31

• Halofuginone
  
  • Licensed for prevention
  • Oral drench
  • Has been used to treat clinical cases (usually not necessary)
  • May be useful where hygiene/colostrum management has failed to control crypto problem

Question 32

What are the uses for NSAIDs in calf scour?

Answer 32

• Use becoming more commonly used for general treatment
• Meloxicam has a license for calf D+
• Anecdotally improve demeanour, gets them back drinking a bit quicker and they look happier etc.