Coccidiosis is generally seen in calves between the ages of three weeks and nine months; clinical signs are diarrhoea or dysentery (bloody diarrhoea).
Coccidia oocysts are highly resistant to environmental conditions, both in housing and on pasture, so premises and fields can remain contaminated for a year or more.
This is why for many farms coccidiosis is an ongoing issue from year to year.
Coccidiosis
There is currently no vaccine available for coccidiosis, but older animals generally are not affected by the disease. This is due to the animals developing immunity as they mature.
Coccidia are excreted in the dung, they are then ingested by a susceptible calf or calves in dung-contaminated bedding, feed or water.
The ingestion of a single coccidia oocyst will develop into thousands of new parasites, each of which destroys the calf’s gut lining.
This then results in very rapid and severe damage to the gut and which can lead to diarrhoea, dysentery (bloody diarrhoea), dehydration, straining, loss of condition and possible death.
In some herds, sub-clinical cases can occur, with very little symptoms present. Calves impacted can often recover without intervention, but thrive in these calves can be affected.
Control measures
Calves that are affected should be removed from the main group and given electrolytes to prevent dehydration.
Consult with your vet to determine if further treatment is required.
Stressors, such as weaning, turnout, change of diet and poor weather may precipitate outbreaks of disease.
For oocysts to become capable of infecting calves, warm, damp conditions are needed, so it is important to avoid dampness in bedding or around water bowls/drinking or feeding troughs.
If there is an ongoing issue with coccidiosis, it should be discussed with the vet to determine measures that can be taken to prevent spread.
There are a number of disinfectants that can be used to control coccidiosis, but these can only be used ahead of housing or arrival of calves – they should not be used when calves are in the shed.