Calf Diarrhoea

Question 1

Name the 5 main agents that cause diarrhoea in calves

Answer 1

• Rotavirus
• Coronavirus
• Cryptosporidium
• E.coli
• Salmonella

Question 2

At what age do calves start to have diarrhoea and why?

Answer 2

At one week old

Almost all calves start excreting bugs

Question 3

What is the MOA of Rotavirus and coronavirus, what are the consequences of this for the calves?

Answer 3

Damage to intestinal lining

→ Malabsorption of milk → Fluid and electrolyte loss → dehydration, acidosis, death

Question 4

When does peak shedding of Salmonella occur?

Answer 4

Following stressors e.g. calving

Question 5

Describe the signs of a salmonella infection

Answer 5

Diarrhoea +/- mucous casts, dysentery, pyrexia, joint infections, abortion, pneumonia, sudden death following septicaemia

Question 6

What are the sources of diarrhoea agents for calves?

Answer 6

• Adult cows: low doses “seeding”
• Other calves - pathogen multipliers = Healthy (older calves), diarrhoeic and recovered
• Environment

Question 7

Describe passive immunity as a host defence mechanism

Answer 7

Local IgG and IgA adhering to mucosal surface. Derived from colostrum.
From first feed
Continued intake

Question 8

Hoe else can host defences help in diarrhoea cases?

Answer 8

Healthy gut flora - suppresses growth of pathogens - “competitive inhibition”
Healthy mucosa – nutrition

Question 9

Describe the importance of the 1st colostrum feed

Answer 9

• “medical colostrum”
• Ig absorbed
• Re-secretion of Ig for 5-7 days –> protection

Question 10

Calve protection after 5-7 days depends on?

Answer 10

• “tonic colostrum”
• Continued intake of Ig rich milk/colostrum
• So .. continue feeding “transition milk for – 4 -7 days e.g. 1+ litre daily with milk replacer

Question 11

How can the environment influence diarrhoea in calves?

Answer 11

• Pathogen load
• Inside vs outside
• Single vs group housing
• Hygiene
• Cleaning protocols

Question 12

How can the timing of a calf being born influence its likeliness of a diarrhoea infection?

Answer 12

“build-up” of bugs in environment
e.g. 15 w calving period –
Risk of death was X10 for calves born in last part of season compared to calves born in first half.

Question 13

In a scour outbreak investigation what questions might you have about calf nutrition?

Answer 13

Did they receive colostrum?
Feeding schedule?
Transitional milk?
Timing of colostrum?
Which milk replacer?

Question 14

How can a milk replacer influence a calf diet?

Answer 14

If too concentrated when mixed up it can cause dehydration due to nutritional scours: lower in fat and protein than regular milk but higher in lactose

Question 15

How can calf scours be prevented?

Answer 15

Minimise exposure
Maximise protection
Minimise stress

Question 16

How can exposure be minimised in dairy calves?

Answer 16

• Clean calving area
• “snatch calve” – remove calf within 2-4 hours of birth
• Clean calf housing
• Hygiene – at feeding
• Hospitalise sick calves

Question 17

How can exposure be minimised in beef suckler calves?

Answer 17

Calve outside:
- Tight calving period
- flow system
- “Sandhills system”
Hospitalise sick calves:
- Do not return to group “at risk”

Question 18

How can protection of calves be maximised on a dairy farm?

Answer 18

• 5-10% of BW (2-3 litres) colostrum within 2 hours, repeat in 6 to 12 hours
• **continue colostrum feeding for 4-10d ‘tonic’

Question 19

How can protection of calves be maximised on a beef farm?

Answer 19

• Adequate cow nutrition
• Feed for 3 weeks pre-calving - protein
• Frozen colostrum e.g. after bad calving
• Vaccinate dam (e.g. Rotavec)

Question 20

In a scour outbreak investigation what questions might you have about the cow management?

Answer 20

Vaccination
Nutrition 
Length of dry period
Disease
Indoor/outdoor
Cleaning routine

Question 21

Describe vaccination of dams for calf protection

Answer 21

• Vaccinate dam ~ 30 days before calving.
• Need to know ~ calving date.
• Works via colostrum / milk.
• Boost milk IgG and IgA levels for 21 days

Question 22

The Sandhills system for beef cattle reduces?

Answer 22

Contact between young & older calves
Build up of pathogens
“eliminates pathogen multiplier effect” - eliminating scours

Question 23

In the Sandhills system, when are groups comingled?

Answer 23

After the youngest calf in a group is 4 weeks old

Question 24

Why can we not use the Sandhills system in the UK?

Answer 24

Sandhills is not feasible if calving indoors (would need a large barn!)

Question 25

How can the Sandhills principles be applied in the UK?

Answer 25

• Turn-out asap
• Segregate cow/calf pairs by age
• 7-10d age spread of calves
• Can mix at 4 weeks of age
• Abolishes pathogen multiplier effect

Question 26

Which calves are affected by Coccidiosis?

Answer 26

Usually in older calves (>21 days)

Question 27

What is the main cause of coccidiosis?

Answer 27

Poor hygiene - especially near feeding troughs.

Question 28

Describe the clinical signs of Coccidiosis?

Answer 28

Dark scour ± blood. Tenesmus.

Usually bright.

Question 29

How is coccidiosis diagnosed?

Answer 29

Faecal oocyst count

Question 30

How is Coccidiosis treated?

Answer 30

Sulphonamides

Question 31

Which calves are affected by necrotic enteritis?

Answer 31

2 - 6 month old suckler calves

Question 32

Describe the features and signs of necrotic enteritis

Answer 32

• Usually sporadic cases
• Usually fatal
• Aetiology unknown
• Pyrexia (> 39.5 C), pale mucous membranes.
• Leucopaenia, thrombocytopaenia
• PM - necrotic lesions of gut & respiratory tract

Question 33

Describe the signs of peri-weaning scour syndrome

Answer 33

Pasty scour, poor growth,

Bloat, pot - belly etc.

Question 34

What is the cause of peri-weaning scour syndrome?

Answer 34

No bugs yet implicated.
Dietary origin?
- Ruminal development pre - weaning