Neonatal Calf Diarrhea

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Neonatal Calf Diarrhea


Scours continues to be the greatest single cause of death
of calves in the world. A complex, multifactoral disease
involving the calf, nutrition, environment, and infectious
agents.  Decades of research have been dedicated to
obtaining a better understanding of this disease complex.



The list of bacteria and viruses that can potentially cause
diarrhea is quite large.

There are six major pathogens that cause diarrhea in
neonatal calves:

• enterotoxigenic Escherichia
coli K99,

• rotavirus, coronavirus,

• Cryptosporidium parvum,

• Salmonella spp.,

• and Clostridium perfringens type C.

The color and consistency of the feces and gross lesions
can look similar, no matter the causative agent. 
Therefore laboratory identification of the infectious agent
and histopathology are imperative to obtaining a
diagnosis.  It should also be noted that it is common
for more than one pathogen to be causing the disease, and
that pathogens causing the disease on a farm can change
from year to year.  These facts make it imperative
that your veterinarian identifies the causative agent(s) to
better establish proper prevention and treatment protocols.


In the early stages of diarrhea, the calf appears bright,
eats and drinks well, and the only evidence of disease is
an increase in the volume and water content of the feces.
The stool volume and fluid content increase as the
condition progresses and the material being passed becomes
a clear liquid. At this stage the base of the tail and
hindquarters simply appear wet. The loss of body fluid and
electrolyte through the passage of large volumes of watery
feces causes signs of dehydration in other parts of the
body as well. The hair coat and skin become dry and
scruffy, the abdomen gaunt, the eyes, nose and mouth dry.
The skin feels leathery to the touch. As the calf’s
condition deteriorates further, the eyes sink into the
sockets, the nose becomes dry, the skin very leathery and
after lifting (tenting) the skin will only slowly return to
the normal position. The animals are usually quite weak at
this time and many are unable to stand or lift their heads.
Death is not far off.

The calf’s temperature is of little assistance in making a
diagnosis of scours. The temperature is usually normal or
slightly elevated in the early stages of the
and as the animal’s condition deteriorates the temperature
becomes subnormal.


The most common cause of death in diarrheic calves is
dehydration, electrolyte imbalance, and acidosis. 
Replacement of fluid and electrolytes can be either orally
or intravenously depending on severity of illness. 
Calves that are standing and have a suckle reflex should
respond to oral fluid and electrolyte replacement. 
Calves that are weak or unable to rise and/or have a weak
or absent suckle reflex will require intravenous
therapy.  Your veterinarian should be contacted
immediately if there is need of intravenous treatment.

The increased energy and protein requirements of the
diarrheic calf necessitate it getting milk as quickly as
possible.  Calves that are being treated with oral
electrolyte solutions should not be withheld from milk
longer than 24 hours.  Oral electrolyte solutions
containing bicarbonate and citrate are excellent
alkalinizing agents but have been shown to reduce milk
digestibility by interfering with abomasal milk clot
formation.  Therefore they should not be used on
calves that are receiving milk concurrently. Acetate-based
solutions can be fed concurrently with milk.  Systemic
antibiotics can be used if deemed necessary by your

the Disease

Prevention of neonatal diarrhea in calves is
two-fold in nature.  First is insuring, maintaining,
and increasing the disease resistance of the calf and
secondly is decreasing the concentration of pathogens
(bacteria and/or viruses) to which the calf is exposed.


Disease Resistance in the
Neonatal Calf

1. Provision of
adequate energy, protein, and minerals during the last 3
months of pregnancy for optimal immune system development
in the fetus.  Cows and heifers should gain about 1
pound per day for fetus and placenta development. 
Adequate nutrition is necessary to maximize colostrum
quantity and quality.  Antibodies are proteins and
adequate protein intake by the dam helps insure antibody
production.  Colostral antibodies are an extremely
important supplement to the calf’s innate immune mechanisms
in providing disease resistance. 

Serum maternal antibody levels in the calf depend on the
amount of antibodies absorbed by the intestine and is
dependent on quantity of antibody consumed, timeliness of
consumption, and absorptive capacity of the
intestine.  Quantity is dependent of quantity produced
by the dam, udder and teat conformation, and motherability
of the dam.  The ability of the intestine to absorb
colostral antibodies begins to decrease at birth, ~ 50%
absorptive ability at 12 hours of age, and completely
closes by 24-27 hours of age.  The ability of the
intestine to absorb antibodies appears to be adversely
affected by weather extremes and stresses such as
associated with a difficult birth.  Therefore events
that increase the time interval from calving to colostrum
consumption will adversely affect the calf’s ability to
resist disease. This lack disease resistance has been shown
to increase the chance of disease, death and decreased
productivity in the neonatal period and to continue through
the feedlot period. 

2. Specific colostral
antibody enhancement using vaccines that contain
rotaviruses, coronavirus, E. coli K99, and Clostridium
perfringens type C antigens, can be helpful in preventing
calf scours.  They must be administered to the dam
according to the manufacturer’s recommendations to maximize
antibody development in the dam and subsequent secretion of
antibodies into the colostrum. 

3. Other products used
to provide protection to specific pathogens are oral
rotavirus and coronavirus vaccines, which is used to
provide protection against intestinal infection by these
two viral agents.  This oral vaccine must be
administered prior to the calf receiving colostrum. 
Products containing antibodies to E. coli K99 can provide
short-term protection for the calf.  Your veterinarian
should be consulted about these products.

Decreasing Pathogen Exposure
to the Calf

1. Calving in clean and dry areas. 

2. Calve heifers earlier than the cow herd. 

3. Avoid congregating.

a. Avoid hay feeding in calving pastures by setting aside
pastures during the summer to stockpile forage for
utilization during calving time. 

b. Move pairs to larger pastures promptly 

c. If hay is fed, use hay feeders and move feeders

4. Use biosecurity and biocontainment measures for all
herd additions: 

a. Isolate, quarantine, and perform appropriate tests on
all herd additions. (See section on Biosecurity in the Beef

b. Introduce pregnant herd additions at least 30 days prior
to the start of calving season.  This will allow time
for exposure to new pathogens, antibody development and
secretion of antibodies into the colostrum. 

c. Do not add calves to the herd until the youngest calf in
the herd is over 30 days of age.  Buying a calf at a
livestock auction or from a dairy for a cow that has lost a
calf can introduce diseases that your herd may not have
immunity against.

5. Isolation and treatment: 

a. Remove sick calves from the herd immediately.  One
sick calf can produce overwhelming pathogen exposure by
shedding as many as 100 million bacteria or viruses per
milliliter of feces (500 million bacteria and or viruses
per teaspoon of feces). 

b. Treating the sick calves should occur after handling the
well calves.  Clean and disinfect all equipment. 
Clothing, boots, gloves, etc. worn while treating sick
calves should not be worn when handling well calves.

Take Home

1. Bacteria and/or
viruses and decreased calf resistance primarily cause calf
diarrhea complex to disease. 

2. The affects in the calf include; dehydration,
electrolyte imbalance, acidosis, increased energy
requirement, loss of appetite, depression, and death. 

3. Treatment is based on replacement of fluid and

4. Prevention is two-fold and based on increasing the
calf’s resistance to disease and decreasing the calf’s
exposure to disease (pathogens). 

5. Identify problems early and work with your

6. Remember mother nature’s disease prevention
method.  If the population of a species in an area
increases to the critical point of overpopulation, three
things can happen that lower population pressures:  1)
Increase in predators, 2) starvation, or 3) disease. 
The result is a well-fed manageable population that has a
high degree of resistance to disease.