Could employing faecal egg counts on farms to determine the correct time for dosing actually be aiding the spread of parasites on farms?

Should farmers instead be dosing livestock while egg counts are low to prevent increased burdens and stop them hampering growth rates?

Prof. Eric Morgan from Queens University Belfast
Image: Zoetis

Those were just two of the major issues explored during an international event hosted by animal health company, Zoetis, at its Dublin headquarters, where the unveiled some of its latest innovations and products.

One of the keynote speakers during the event, Professor Eric Morgan from Queens University Belfast, also highlighted how changes in parasite prevalence are a factor that farmers cannot afford to ignore.

Prof. Morgan is part of Co- Adapt, a project funded by UK Research and Innovation (UKRI), which is examining the management of endemic coinfections in ruminant livestock under climate change.

He believes that targeting treatments is the way to advance animal health sustainably and can also ensure that farmers meet production targets while using less resources.

Faecal egg counts

New legislation that is scheduled to be passed into Irish and European law will result in a need for dosing of livestock – with results of a faecal egg count showing the need for dosing.

But does the solution to controlling parasites in livestock lie with using data, technology and weather predictions to determine when dosing is required?

According to Prof. Morgan this is the question that he, together in partnership with Zoetis, hopes to answer via the Co-Adapt Project.

This is a new project with little to no results currently available and deals with adaptive management of parasitic infections.

Speaking at Zoetis event in Dublin, Prof. Morgan said: “Grazing livestock are full of worms and will continue to be, unless they figure out how to use a toilet.

“It is normal to have parasites and different types of parasites, such as lung worm and liver fluke.”

Morgan also noted that changes in weather condition can have a major impact on infection pressure.

He also outlined that across an estimated 18 countries in Europe controlling parasites on farms could cost in the region of around €1.8 billion each year.

Parasite control

The solution to parasites is suppression, according to Morgan, but the practice for the last 50 years has been to put chemical antiparasitic’s in animals as early as possible for as long as possible.

But that means that the life cycle of these parasites is on the pasture, so animals become re-infected once the effectiveness of the drugs has worn off.

He also noted that issues with resistance is now forcing farmers to change their practices.

Prof. Morgan said that global warming is also have an impact on parasites and particularly around when they affect livestock because warmer weather leads to livestock being affected by parasites earlier in the year.

Previously it was somewhat predicable as to when these parasites would become an issue, but it is now extremely variable.

Prof. Morgan told the event that often the first indication of worms is slow weight gain, but he believes that by this stage the treatment is too late.

“What we really need to be able to do is weight animals, then go back in time.

“How do we have risk based targeted approaches, that are proactive before we can measure anything in the animal – that’s our challenge,” he said.

Prof. Morgan also believes that the “major challenge is when to treat to prevent future risk”.

“If we know where animals were and egg counts when they came out,” he said.

“We can use the weather such as temperature and rainfall to predict the risk and say that these animals are entering a pasture were you should treat them.”

The tool would highlight the period when the risk from parasites is high and this would allow farmers to treat their livestock before burdens become too high and impact on the animal.

Morgan noted that legislation is currently being explored on what egg counts need to be treated.

He said that other practices do not work and the best treatment of worms is to supress them when burdens are low on pasture and in livestock.


During the event a number of other speakers also detailed how Zoetis is now developing products that will help farmers to predict, prevent and detect/treat illnesses or disease in livestock.

Zoetis outlined how they are using genomics to identify animals with lower levels of illness and then using these animals to bred the next generation from.

Various guest speakers also highlighted the specific benefits of vaccinations and the roles they have to play on farms prevent illness and disease.

One product such as Varscan Mastigram+ is a first on-farm mastitis diagnostic system which can identify gram-positive mastitis in cows between milking.

This allows for more effective and quicker treatment of cows, thus reducing recover time and or loss of production.