Coccidiosis In Calves

Coccidiosis in calves is caused by a protozoa parasite called Emeria Sp. This little parasite has a 2- 4 week lifecycle following ingestion of a developing oocyst (egg), which undergoes a series of replications and divisions as it invades the lining of the gut wall. This rapid invasion causes scours and ill thrift. 

Common signs relating to coccidosis infection are:

  • Sudden onset scours often with blood and mucus present 
  • Straining (often unproductive)
  • Chronic ill thrift and wasting in a whole mob of calves
  • Poor appetites

Infection is likely to spread quickly to most calves in the group and whilst mortality (deaths) is usually low, the effect on growth rates is significant. 

The parasite loves wet damp conditions, so is usually seen in calves outside if it is muddy and wet  or inside if stocking rates are high and hygiene and drainage is poor.

Oocysts are likely to be present on every farm and can remain on pastures or in contaminated areas for over a year thus infection can pass from year to year. Like many diseases, animals develop immunity as they age so adult cows are not affected by coccidia.

Many of you may use a calf meal with a Coccidiostat included. This is great but there is still a risk of coccidiosis in the following situations:

  • animals that don't eat much meal don't ingest sufficient quantities of the coccidiostat
  • animals at weaning become stressed and this weakens their immune defences
  • the high coccidial load in a heavily contaminated environment is unable to be suppressed by a coccidiostat

The good news is that in the event of an outbreak there is an oral treatment containing Toltrazuril available so speak to one of the vets if you have any concerns.

If you have had coccidiosis in the past it is worth noting that a new drench was launched last year called Turbo Initial which is able to treat both worms and coccidiosis at the same time and is therefore a good choice first drench in these situations.