Work is under way to understand the prevalence of three new species of Eimeria – the parasite which causes coccidiosis in poultry – in the UK and Europe.
Elanco Animal Health is assisting researchers from the Royal Veterinary College (RVC) to assess how widespread the new species are.
It follows findings from an independent study, carried out by researchers at the RVC, which identified three new Eimeria species – Eimeria lata, Eimeria nagambie, and Eimeria zaria – circulating in chickens.
Professor Damer Blake from the RVC described the three new species as “hidden forms of coccidiosis” and said their presence could change the way the disease is managed on farms in the future.
“We’ve known about the main Eimeria species for decades and we understand how to control them, however in 2008, a paper was published describing what seemed to be new genotypes of Eimeria in Australia,” said Blake.
“They were first detected on a farm that was using anticoccidial vaccines, and they broke through the vaccine and caused increased morbidity and mortality.”
He said: “Five years later, we did a molecular survey of Eimeria around the world, and we found these new genotypes were really common across the southern hemisphere, and when we looked in the northern hemisphere, they were there as well.”
He says the latest study confirmed that the genotypes being reported across the world were new, standalone species, and that the current phase of work is designed to ascertain how widespread they are.
“We are working with Elanco to pick up samples from birds across Europe and the UK to see how common these new Eimeria species parasites are and help us assess what level of risk they pose,” said Blake.
He says the new species appear to be associated with a malabsorptive type of coccidiosis, which is less likely to cause death than some other species, but they can still have a significant impact on performance.
“These strains create a lot of mucus in the intestine which results in poor feed conversion and the birds not growing very well,” said Blake.
Most significantly, he says research has shown that these new species appear to escape anticoccidial vaccines, posing questions over future control programmes in some parts of the world.
“As far as we can see, anticoccidial medications, like Maxiban and Monteban, work just as well on these species as other species, so they’re only really a challenge on farms which move from drug prophylaxis to vaccine prophylaxis,” said Blake.
“The vaccines for layers and breeders protect against the established Eimeria species, however broiler vaccines tend to be more targeted.
“This research may question this approach and make us reassess how we look at coccidiosis control programmes in the future.”