Vaccination brings peace of mind to Wexford sheep farmer after previous abortion outbreaks
Sheep Farmer Edward Earle, Co. Wexford
Edward Earle farms alongside his parents, John and Margaret, and his younger sister Gillian. The family run 300 ewes across 80 acres, with a split flock of 30 pedigree Texels that lamb in January, and a mid-season commercial flock that lamb from the 10th of March. Enzootic Abortion of Ewes (EAE) is a concern for many sheep farmers, and for Edward, discovering it had entered his flock back in 2016 was a worry.
‘’We had a number of stillborn lambs just before lambing commenced,’’ Edward recalls. ‘’There were a lot of weak lambs born, which brought a lot of extra worry and stress. Each day you walked into the shed, you didn’t know what was going to be in front of you.’’
Advised by their vet, Shane McGuckin of Gorey Veterinary Hospital, who has worked with the Earle family for over 30 years, samples were submitted to the Regional Veterinary Lab in Kilkenny for analysis. The samples tested positive for Chlamydophila abortus, the causative agent of EAE.
An initial outbreak of C. abortus within a flock can lead to 30% or more ewes aborting or giving birth to stillborn or weak lambs. The disease spreads through contact with infected aborted material and can be introduced into a flock through purchased infected animals. The disease is also zoonotic and can cause abortion in women or flu-like symptoms in both adults and children.
‘’The Earle family are very proactive when it comes to flock health,’’ said Shane. ‘’They always want to investigate any illnesses and take measures to reduce the incidence of disease and improve the health and live weight gain of their stock.’’
Sheep farmers Gillian and Edward Earle with Shane McGuckin of Gorey Veterinary Hospital.
Working with Shane, a vaccination programme using Enzovax, a vaccine used to reduce abortion caused by Chlamydophila abortus infection in susceptible female breeding sheep, was implemented. Under this programme, initially all breeding females were vaccinated four weeks prior to breeding in 2016 and subsequently each year replacements are vaccinated four weeks prior to breeding, while the main flock receives a booster every three years.
‘’Since we’ve introduced the vaccination programme for Enzovax, we’ve seen a major reduction in EAE cases, which gives us peace of mind,’’ said Edward.
A second challenge solved by a second vaccine
More recently, the farm faced a new challenge. Two lambs died, and samples were sent for analysis again. This time, the samples tested positive foy Toxoplasma gondii, the causative agent of toxoplasmosis.
‘’Toxoplasmosis is a bit different from EAE because there are intermediate and definitive hosts involved,’’ said Shane. “Good hygiene is important, and you need to prevent cats from accessing feed and forage. Whereas EAE is spread from sheep to sheep at lambing time.’’
Toxoplasma gondii is commonly found in the environment, leaving most flocks susceptible to infection. Young cats are the main source of infection, with a single dropping from one infected cat containing enough eggs to infect up to 100 ewes. Toxoplasma gondii also poses a zoonotic
risk especially to pregnant women and immunosuppressed individuals.
A vaccination programme using Toxovax, a vaccine for breeding female sheep to reduce the effects of infection by Toxoplasma gondii, was introduced alongside the existing Enzovax programme. Toxovax can be administered at the same time as Enzovax, at different injection sites. When using both vaccines, they should be given at least four weeks before breeding. When used alone, Toxovax can be administered at least three weeks prior to breeding.
Diagnosis is the foundation
Both Shane and Edward emphasise the importance of laboratory diagnosis before implementing any vaccination programme.
‘’I definitely encourage any farmer, if they have losses on the farm, to talk to their vet and bring samples to the regional lab to understand what they’re dealing with. When you know what you’re dealing with, consider a vaccination programme because it’s a great management tool,’’ said Edward.
Eleanor Brady, Ruminant Veterinary Area Manager at MSD Animal Health, added ‘’Enzootic Abortion of Ewes and Toxoplasmosis are the two most common causes of infectious abortion in sheep in Ireland. Both can be controlled through biosecurity, flock management and vaccination, and the availability of Enzovax and Toxovax means farmers can help protect their flocks against both diseases with a straightforward vaccination programme. Enzovax provides protection against EAE for at least three years, while Toxovax provides protection against Toxoplasmosis for at least two lambing seasons.”
Speak to your vet about the most appropriate management and vaccination programmes for your flock.
For more information visit: https://www.bovilis.ie/sheep/sheep-abortion/?utm_source=agriland+native&utm_medium=digital&utm_campaign=agriland+native+&utm_id=enzo%2Ftoxo
