Diarrhoea or calf scour (Figs 1-2) can be a major cause of
calf mortality and lost profit in many beef suckler herds.
Financial losses result from individual dead calves and the severe
check in growth of many young calves in the group. Oral electrolyte
solutions are expensive and labour costs add further to financial
Purchase of replacement
calves purchased from markets risks introducing many disease
organisms including Salmonella species on to the farm. Other
important enteris diseases that can be introduced by purchased
stock include bovine virus diarrhoea (BVD) and Johne's disease
Fig 1: Mild diarrhoea or scour affecting a 8
Fig 2: Severe diarrhoea in a calf necessitating
intravenous fluid therapy to correct
The most important causes of
calf diarrhoea are rota- and corona-viruses. It is essential to
appreciate that most outbreaks of calf diarrhoea are caused by
viruses and that fluid therapy rather than antibiotic therapy is
the more effective treatment strategy. Antibiotics must only
be used in specific disease situations as directed by a veterinary
As with all animal diseases
prevention is better than cure and an effective veterinary herd
health plan is essential for all beef herds to maintain health and
prevent costly diseases.
Fig 3: Rotavirus infection can produce severe
Rotavirus infection is the most common cause of severe diarrhoea
in young beef suckler calves. Infection can produce the
complete range of clinical signs from no observed abnormality
through to severe diarrhoea (Figs 3-4) and dehydration with high
mortality. There is a build-up of infection with most cases
during the second and third months of the calving period.
Spread of infection occurs most rapidly in housed beef calves.
Calves are most commonly affected at 8 - 14 days old when there
is an acute onset of diarrhoea with the passage of very watery
yellow/green faeces (Fig 3) with infection spreading rapidly among
young calves in the group (Fig 5). Typical early signs
include a reluctance to stand and suck, mild depression and
salivation. The calf rapidly becomes dehydrated and recumbent
(Fig 6). The eyes are sunken and the skin becomes tight and
inelastic. The abomasum and intestines are often distended
with fluid and gas.
The affected calf should be isolated from its dam in a dry,
well-bedded corner of a pen. 1-2 litres of oral electrolyte are
given 4 to 8 times daily. While a stomach tube/oesophageal feeder
can be used once, veterinary advice should be sought if the calf
will not suck fluids through a teat 2 to 4 hours later. It is
important to offer fluid by teat not oesophageal feeder because
active sucking is the best indicator of the calf's
improvement. Repeated administration of oral electrolyte
solutions by stomach tube must only be undertaken if the calf is
improving. Alternate milk (access to the cow) and electrolyte
solution every two to four hours once the calf is improving. Oral
antibiotics are contra-indicated in these calves. Parenteral
antibiotics should only be used to control concurrent infections,
e.g. navel ill, calf diphtheria.
Fig 4: Diarrhoea with the
passage of watery yellow/green faeces in early rotavirus
administered by a veterinary surgeon are essential in dehydrated
calves that are unable to stand unaided (Figs 7-8).
Other causes of diarrhoea in 1-3 week-old calves include
Drugs and staff time employed to treat scouring calves prove
costly (approximately £25 for mild cases treated with oral fluids;
a dead Charolais bull calf may cost as much as £260 to
Once a herd has experienced
problems with rotavirus infection, annual vaccination of the cows
costing £6-8 per cow is essential 1 - 3 months before their calving
Fig 5: Infectious causes
of diarrhoea can spread rapidly among young
Outbreaks of calf coronavirus
diarrhoea are similar to, or more severe than, those observed for
rotavirus infection. Fortunately, coronavirus infection is much
less common than rotavirus.
Typical clinical signs
include depression, reluctance to suck and the passage of faeces
containing mucus and milk curds. The disease can progress rapidly
to weakness, recumbency, severe dehydration and death. Coronavirus
infections cause diarrhoea in calves up to 20 days-old.
Fig 6: Veterinary
attention is essential for recumbent calves.
Treatment for coronavirus
infection is as outlined above for rotavirus. Annual vaccination
with a combined rotavirus, coronavirus and K99 combined vaccine is
an invaluable insurance policy in all beef herds.
Enterotoxigenic E. coli
In calves this term is used
to refer to strains of the bacterium E. coli possessing the K99
antigen. Recent surveys have shown the incidence of K99 E. coli to
be low (around 1 % of diarrhoeic calves), but when infection occurs
in a herd, losses can be high.
characteristically affects calves aged 1-3 days old when there is
sudden onset of profuse yellow/white diarrhoea causing rapid and
severe dehydration. The calf quickly becomes recumbent.
Accumulation of fluid in the abomasum and intestines gives the
abdomen a bloated appearance.
Diagnosis is based upon severe diarrhoea with high
mortality affecting calves aged 1-3 days-old with confirmation
following isolation of K99 + E. coli from faecal samples collected
by a veterinary surgeon.
The main differential diagnosis is
Fig 7: Intravenous fluids
administered by a veterinary surgeon are essential in dehydrated
calves that are unable to stand unaided.
Movement of all pregnant cows
to clean pastures and isolation of newly-calved cows should
markedly reduce the incidence of ETEC disease.
Vaccinate all pregnant
animals immediately with Rotavec-Corona K99 but it will take 10-14
days for sufficient protective antibody to accumulate in the
For all diseases affecting
the young calf the calving accommodation should be kept clean and
well-bedded and preferably mucked out between calvings. Ingestion
of 2 litres colostrum within the first two hours of birth cannot be
Fig 8: Following
intravenous fluid therapy by a veterinary surgeon (Figs
It is only within the last 20 years that C. parvum has been
recognised as a primary cause of neonatal diarrhoea. C.
parvum is not host specific and outbreaks occur when there is a
build up of infection, namely towards the end of the lambing or
calving period when the same buildings are used for autumn/winter
calving then spring lambing as the protozoan parasite can remain
dormant for months.
Diarrhoea is caused by the physical
loss of absorptive area of the small intestine and exacerbates the
viral infections described above. Suckler calves aged 10-21 days
old are most commonly affected. There is a profuse yellow/green
diarrhoea with much mucus present. There is only mild dehydration
but the calf rapidly looses condition over 2-5 days and has a dull
tucked-up appearance. Whilst morbidity is high, the mortality rate
in uncomplicated cases is usually low.
1. Do not use same fields for
fields every year or when clinical cases occur in that
newborn animals immediately on to clean pasture.
In uncomplicated cases ensure
that the scouring calf is properly hydrated and use oral
electrolyte solutions as necessary.
Halofuginone lactate has
recently been licensed for the prevention and treatment of
diarrhoea caused by C. parvum. For prevention of
diarrhoea, calves should be dosed for seven consecutive days
starting within one to two days of birth. For treatment, calves
should be dosed for seven consecutive days starting within one day
of the onset of diarrhoea. Halofuginone lactate has a low toxicity
index and the data sheet instructions must be carefully
Cryptosporidiosis is a
zoonotic disease (can affect man). Children and the elderly are
most at risk when handling calves, less so contaminated
boots/clothing and other indirect sources of infection.