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Coccidiosis is a common parasitic
protozoan disease of cattle.
Most cases occur during the winter months, but may
develop any time cattle are crowded together. Bovine
coccidiosis is seen most frequently in calves that are six
to twelve months of age. Calves become infected when placed
in lots contaminated by older cattle or other infected
calves. Mature cattle may be infected when they are brought
in from pastures and crowded into feedlots or barns.
Coccidiosis occurs mainly in
calves and is usually accompanied by diarrhea varying in
severity from watery manure to one containing blood. Animals
affected with coccidiosis often strain due to irritation of
the lower bowel and rectum. Blood may appear in the manure
after the second or third day of diarrhea. Dehydration,
weight loss, depression, loss of appetite and occasionally
death may also be observed.
Infections that
fail to produce signs of disease may nevertheless affect the
growth and health of an animal. Calves with only a light
infection usually show no signs of disease, but shed oocysts
in manure, so the oocysts accumulate in pastures, yards,
barns or on the hair coats so that severe coccidiosis may
develop when new calves are placed in these areas.
Cattle that
recover from coccidiosis usually become immune to later
infections, but they may continue to pass oocysts in the
manure, thereby providing a source of infection for
susceptible calves. Older
cattle are often carriers of coccidia, and although they are
immune, they continue to pass oocysts in their manure.
Prevention
Good
management practices are important when establishing
parasite control programs. The primary concern in
coccidiosis outbreaks is the potential to spread the disease
to other susceptible animals in the herd.
Follow these tips when trying to prevent an
occurrence of coccidiosis:
1.
Drinking water and feed should be protected from
contamination with manure. Cattle, especially calves, should
not be fed directly on the ground where manure can
contaminate the feed.
2.
Excessive moisture should be drained from the pens
and replaced with ample dry bedding.
3.
Infected animals should be isolated to avoid exposure
to other cattle.
4.
Use lots that are well drained.
Treatment
There
are several anticoccidial drugs available that may be used.
Outbreaks of coccidiosis in calves and feeder cattle may be
handled by mass medication using sulfonamides, amprolium or
monensin added to either the feed or the water. Specific
recommendations should be obtained from your veterinarian.
Dr. Murray J. Kennedy, Food Safety Division, Alberta
Ag, Food, & Rural Development
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