Page 2 - CalfCare - Management of the Scouring Calf
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What is scour?
Scour refers to watery or custard-like faeces. It results from a
badly damaged gut, which leads to a loss in function. An
intestine that is not functioning properly causes the calf to lose
salts and water in the form of diarrhoea. The initial damage to
the gut is caused by a variety of infectious agents, including
parasites, viruses and bacteria.
Once the damage is done, the calf will continue to scour until
the intestine is repaired. No treatment is available to speed up
this repair time.
Calves that are fed high volumes of milk (especially ad-lib fed
calves) will normally have somewhat looser faeces.
Damage to villi results in scour as nutrients will not be
absorbed properly
What causes scour?
A number of infectious agents can cause scour in calves and often more than one of them is involved.
Parasites Cryptosporidia**
Coccidia* (generally in calves older than 3 weeks) most common
Viruses Rotavirus
Coronavirus less
common
Bacteria Salmonella**
E. coli (only in calves under 5 days of age) rare
*Coccidia cause diarrhoea in older calves, more information overleaf
**Cryptosporidia and Salmonella may cause diseases in humans. Good hygiene when dealing with sick calves is essential to avoid infecting
yourself.
Contrary to popular opinion, it is not possible to tell from the appearance of the scour what has caused it. Fresh
whole milk or good quality milk replacer given in reasonable portion sizes does not cause scour. Scour is rarely
caused by nutritional reasons (over-feeding, poor quality milk replacer) alone and generally will have an
underlying infectious cause.
Should you treat with antibiotics?
Antibiotics should be given by injection only when the calf looks very sick (weak or unable to rise, sunken
eyes) or has a temperature outside of the normal range of 38.5 to 39.5°C (See Veterinary Technical Note).
Antibiotics do not work against the parasites and viruses that are the most common causes of calf scour. Thus
it makes no sense to treat calves with antibiotics just because they are scouring, unless there is an
accompanying fever or the calf looks sick. If antibiotics are used when they are not needed, there is a good
chance that they won’t work when they are really needed (See Background Information).
What is scour?
Scour refers to watery or custard-like faeces. It results from a
badly damaged gut, which leads to a loss in function. An
intestine that is not functioning properly causes the calf to lose
salts and water in the form of diarrhoea. The initial damage to
the gut is caused by a variety of infectious agents, including
parasites, viruses and bacteria.
Once the damage is done, the calf will continue to scour until
the intestine is repaired. No treatment is available to speed up
this repair time.
Calves that are fed high volumes of milk (especially ad-lib fed
calves) will normally have somewhat looser faeces.
Damage to villi results in scour as nutrients will not be
absorbed properly
What causes scour?
A number of infectious agents can cause scour in calves and often more than one of them is involved.
Parasites Cryptosporidia**
Coccidia* (generally in calves older than 3 weeks) most common
Viruses Rotavirus
Coronavirus less
common
Bacteria Salmonella**
E. coli (only in calves under 5 days of age) rare
*Coccidia cause diarrhoea in older calves, more information overleaf
**Cryptosporidia and Salmonella may cause diseases in humans. Good hygiene when dealing with sick calves is essential to avoid infecting
yourself.
Contrary to popular opinion, it is not possible to tell from the appearance of the scour what has caused it. Fresh
whole milk or good quality milk replacer given in reasonable portion sizes does not cause scour. Scour is rarely
caused by nutritional reasons (over-feeding, poor quality milk replacer) alone and generally will have an
underlying infectious cause.
Should you treat with antibiotics?
Antibiotics should be given by injection only when the calf looks very sick (weak or unable to rise, sunken
eyes) or has a temperature outside of the normal range of 38.5 to 39.5°C (See Veterinary Technical Note).
Antibiotics do not work against the parasites and viruses that are the most common causes of calf scour. Thus
it makes no sense to treat calves with antibiotics just because they are scouring, unless there is an
accompanying fever or the calf looks sick. If antibiotics are used when they are not needed, there is a good
chance that they won’t work when they are really needed (See Background Information).

