Analysis shows that approximately one third of faecal samples submitted to the Regional Veterinary Laboratories (RVL) test positive for coccidiosis in May, June, July and August, according to Animal Health Ireland (AHI).
Veterinary research officer at the Department of Agriculture, Food and the Marine (DAFM) RVL in Kilkenny, Maresa Sheehan said recently turned-out calves may be at risk from coccidiosis.
Coccidiosis should be considered as a possible cause of diarrhoea in calves at pasture, particularly shortly after turn-out, Sheehan said in AHI’s latest edition of its Beef HealthCheck Newsletter.
Coccidiosis is widespread in cattle farming, mainly causing clinical disease in calves from three weeks to nine months of age. Coccidia parasites affect the small and / or large intestine where they damage the intestinal wall.
If numbers of parasites are high, this damage results in changes that can lead to diarrhoea (scours), bloody diarrhoea, dehydration, straining, loss of condition and possible death, the veterinary research officer said.
Coccidiosis
As there are a number of possible causes of diarrhoea / scour in calves at grass, Sheehan said it is recommended that at least five or six faecal samples from an affected group are submitted to a laboratory to aid diagnosis.
“A correct diagnosis allows targeted medications and preventative measures to be used and avoids incorrect treatments e.g. giving an anthelmintic for parasitic gastroenteritis/worms when coccidiosis is the problem,” she added.
As bloody diarrhoea is not always a feature of coccidiosis and the affected animal may just have a watery diarrhoea, Sheehan said it is important to properly investigate the cause of the diarrhoea.
Coccidia oocysts (eggs) are excreted in the dung and ingested by a susceptible calf in dung-contaminated bedding, feed or water. Calves that have carried a high infection of coccidia from housing may continue to be affected from that species at grass.
Infective coccidia eggs are “highly resistant” to environmental conditions, both in housing and on pasture, and therefore premises and fields can remain contaminated for a year or more, according to Sheehan.
“Stressors, such as weaning, turnout, change of diet and poor weather may precipitate outbreaks of disease.
“As warm, damp conditions are necessary to allow eggs to become capable of infecting animals, it is important to avoid dampness in bedding or around water bowls/drinking or feeding troughs,” she added.
The following advice was given by the veterinary research officer in AHI’s latest edition of its Beef HealthCheck Newsletter to reduce the risk of coccidiosis:
- At pasture, leaking troughs will create a “high-risk environment” for coccidiosis. Water troughs should be regularly emptied and cleaned, where possible;
- Feeding meal directly on the ground should be avoided. The use of higher feeding troughs should also help prevent faecal contamination of feed;
- Pasture rotation, where possible, is a useful tool to avoid build-up of high concentrations of coccidia eggs in areas dedicated for use by susceptible animals;
- As calves are weaned and moved to pasture, clean out, disinfect and rest calf houses to reduce the coccidial load before next calving season;
- The exposure of coccidia to sunlight and dry conditions and the use of disinfectants effective against coccidiosis will help calf rearing next year.
Beef HealthCheck is an AHI-led programme developed in collaboration with Meat Industry Ireland (MII). The programme has developed tools to assist farmers and their veterinary practitioners to control losses due to liver fluke and pneumonia.