| ||What is coccidiosis?
Coccidiosis is a parasitic disease that affects cattle, sheep, goats, swine and poultry. The disease is caused by microscopic protozoan organisms known as coccidia that inhabit the cells of the intestinal lining. Each class of livestock has a species-specific coccidia; there is no cross-infection between species.
At least nine species of Bovine coccidia occur in Alberta, but only two species, Eimeria zuernii and Eimeria bovis cause the disease coccidiosis. Eggs are produced within cattle, which pass out in manure. Under proper temperatures, moisture and oxygen, sporozoites form within the egg after 3 to 7 days. These eggs then re-enter cattle if they are eaten. Sporozoites enter the intestinal cells and begin to divide, causing the cell to rupture. This allows for the spread of infection to other intestinal cells, possibly destroying many intestinal cells. After approximately 14-6 days, fertilized eggs are again produced, and pass out through manure of infected animals.
What are the symptoms of coccidiosis?
The severity of disease depends on several factors, including the number of eggs eaten, the species of coccidia present, and the age and condition of the animal. The symptoms usually include diarrhea varying in severity from watery manure to containing blood. Dehydration, weight loss, depression, loss of appetite and occasionally death may also occur. Even less severe infection, where there are no signs of the disease, may affect the growth and health of an animal. Additionally, nervous coccidiosis can develop in some calves with acute intestinal coccidiosis. This is usually observed in feedlot operations, especially during cold spells, with symptoms that vary in severity from minor muscular incoordination and loss of balance to intermittent or continuous seizures.
How am I sure it is coccidiosis?
These symptoms are not specific to coccidiosis, and a veterinarian should be consulted if the above symptoms are observed. Diagnosis is made from a combination of herd history, clinical signs, physical examination of the animal and microscopic examination of manure from the rectum of the affected animal.
How does an animal become infected?
Bovine coccidiosis is most frequently seen in calves that are 6 to 12 months of age. Animals become infected when placed on pastures or in lots that have been contaminated by mature cattle or other infected calves. Mature cattle can also be infected when they are brought in from pastures and crowded into feedlots or barns. Most cases of coccidiosis occur during the winter months, but infection can develop whenever cattle are crowded together.
Cattle with light infections or animals that recover from coccidiosis (and usually become immune to later infections) can still continue to pass eggs in manure, and provide sources of infection for susceptible animals.
How can infection be prevented?
Young susceptible animals should be kept as clean and dry as possible. Feeding and watering equipment should be cleaned and protected from fecal contamination. Avoid feeding cattle on the ground, especially calves, so manure does not contaminate the feed. Excessive moisture in pens should be drained, and dry bedding should be provided.
Use pasture that are well drained, and avoid forcing animals to graze down to the roots of the plants so they do not eat large numbers of parasites. Try to keep grazing to a minimum in areas where cattle congregate (e.g. by water).
Whenever possible, infected animals should be isolated as soon as possible to avoid exposure of infected manure to other cattle.
Can coccidiosis be treated?
A veterinarian should always be consulted when deciding on treatment protocol. There are several anticoccidial drugs available. Outbreaks of coccidiosis in calves and feeder cattle can also be handled by mass medication using sulfonamides, amprolium or monensin added to either feed or water. Specific recommendations should be obtained from a veterinarian.
Coccidiosis in Cattle (1)
Coccidiosis in Cattle (2)
Prepared by Sue De Bruijn, Ag-Info Centre, Alberta Agriculture & Rural Development