Development and Optimisation of the FECPAKg2 System to Speciate Protozoan Infections in Livestock and Improve Productivity and Sustainability

Coccidiosis in cattle and sheep is caused by infection of the alimentary tract with protozoan parasites called Eimeria _spp_. There are many species of _Eimeria_ but only a small proportion of these are commonly associated with clinical disease; other _Eimeria_ species may be present but are not considered important pathogens. Coccidiosis can affect animals at any stage in their lifetime, however young animals are most vulnerable due to their low immunity. Disease can be seen all year round; it is most common that outbreaks will occur during the wet seasons of the year. The UK continues to get warmer and wetter each year as a result of global warming.

Infection causes a loss of absorptive capacity of the gut with consequent diarrhoea which can be severe. Affected animals usually suffer weight loss, pain and protracted convalescence resulting in welfare considerations, lengthy delays to finishing, susceptibility to secondary bacterial infections and extra feeding costs, alongside cost of treatment (including labour and medicines). It is one of the most economically significant diseases in cattle and sheep due to the considerable impact on production at herd/flock level.

Current diagnosis involves faecal testing for presence of oocysts. Interpretation of faecal samples is challenging because there may be low numbers of oocysts present in the faeces of normal calves, and not all _Eimeria spp._ are considered to be pathogenic. Demonstration of large numbers of oocysts in faecal samples is helpful but speciation is essential to determine whether coccidia are pathogenic. Current practice for speciation requires sporulation of the oocyst (which currently takes between 3 and 5 days) and then microscopic examination of the sporulated oocyst by a highly skilled technician. However, this is rarely undertaken in field outbreaks due to cost and time taken to get results from external laboratories to the veterinary practice. With these limitations and the pressures for prompt treatment regarding welfare and productivity, farmers would usually blanket treat animals with a non-targeted treatment.

The existing FECPAKg2 system developed by project partner Techion is a rapid on-farm diagnostic platform for faecal egg count testing currently used to detect parasitic nematode infections in ruminants and equids. This project will assess the feasibility of adapting the existing FECPAKg2 system to detect protozoan parasites, alongside development and integration with automated image recognition software to objectively speciate using digital images of un-sporulated oocysts (e.g. immediate diagnosis using fresh faecal samples).