Is there something in the water? Identifying and addressing Cryptosporidium in sheep.

Cryptosporidium is a group of parasites which infect the gastrointestinal tracts of numerous species, including cattle, sheep, goats, pigs, chickens, horses and deer, but can also have an impact on human health. Reducing the incidence of cryptosporidium in livestock can therefore have a twofold advantage, improving animal health and productivity and reducing contamination of the environment, leading to a reduction in human health risks.

There is still a low level of understanding regarding the persistence, transmission routes, and management options available regarding cryptosporidium in sheep. Typically, infection presents as high lamb mortality under one month of age and ill thrift of lambs. The scale of production losses to the sheep industry as a result of cryptosporidium is unknown.

A group of farmers in Powys have identified cryptosporidium in calves and lambs on their farms in previous years and are now undertaking this project to determine the prevalence and sources of the parasite on their farms. They hope to increase their understanding of the pathways by which it is transmitted among sheep and also identify measures they can take to control and prevent the disease in sheep.
 

Project Plan

  • Each farm will have a biosecurity review from their local vet. Some faecal samples will be taken from ewes to assess cryptosporidium levels in the breeding flock at the outset of lambing.
  • The farms infrastructure and watercourse will be sampled and tested for cryptosporidium. This will include the lambing sheds, bedding, pasture and water supplies.
  • Faeces from new born lambs which show clinical signs of having cryptosporidium (diarrhoea, dehydration) will be sampled at:
  1. 1 week old 
  2. 10 days old 
  3. 2 weeks old 
  4. At weaning 3-4 months old 

 
The sampling methodology will be assessed after year one, and adjusted accordingly for repetition in year two. As a result of the biosecurity review, infrastructure sampling and the sampling results of lambs tested, the group will work together to develop procedures to reduce the prevalence of Cryptosporidium on the farms. Recommended management options may include:

  1. Steam cleaning buildings to kill oocysts (dormant stage of parasite).
  2. More frequent cleaning and disinfection of livestock sheds.
  3. More frequent bedding down with straw.
  4. Quarantine of scouring animals.
  5. Ensuring that lambs receive adequate quantities of good quality colostrum, quickly.

 
Potential Outcomes

  • Identification of the possible sources of Cryptosporidium infection on farms.
  • Develop an understanding of the prevalence of Cryptosporidium in the farm environment.
  • Adopt procedures which will manage and/or prevent Cryptosporidium infection and share these approaches with the wider agricultural industry.
  • Provide recommendations about the intervention measures that could be adopted to reduce the risk and prevalence of Cryptosporidium in surface water, with specific reference to sheep and cattle systems in Wales.