Programme encouraging farmers to be up to date with C.ovis control

Ovis Management Programme manager Michelle Simpson.

Farmers are being urged to keep up to date with measures to control C. ovis - sheep measles - after the Ovis Management programme reported a spike in infection rates.

Data from meat processors for October, the first month of the new season, identified that 1.38 % of lambs processed throughout the country were recorded as being infected.

That compares to 1.13% for October 2023.

Ovis or sheep measles is caused by the Taenia ovis tapeworm.

Although it poses no risk to human health, it can cause blemishes in sheep meat, which is undesirable for consumers and particularly for the export market.

The programme works to promote the control of C. ovis through communication and collaboration and raising awareness of the importance of farmers regularly treating their dogs for tapeworm.

Programme manager Michelle Simpson said to minimise sheep measles in New Zealand it was critical to ensure all dogs on farms where sheep graze are dosed regularly with the required tapeworm treatments, and also any dogs visiting the farm.

“We do not believe we can eradicate C. ovis but the aim is to control it at around 0.5%,” Simpson said.

“There are likely to be a number of reasons for the increase. The warmer climate and some moist conditions may mean that eggs are surviving longer. Farmers have a lot on their minds and a lot of expense, so worming programmes may have slipped a bit, but it is important to keep on top of it because an outbreak costs farms a lot of money in condemned stock.

“The prevalence changes as the season goes on. If we start the season with a high prevalence, then we are likely to end it with a high prevalence, too.”

Simpson said farmers breeding lambs for trading needed to make sure they were taking all necessary steps to avoid sheep measles in their flocks.

“A lot of people dealing with this have inherited the problem.

“Traders need to ensure they have the same treatment programme in place to protect the investment of their buyers.

“This isn’t pointing the finger at anyone. It’s about making sure everyone is on the same page.”

Dogs can become infected by eating untreated meat or offal infected with live cysts.

C. ovis is then spread to sheep through tapeworm eggs in dog faeces left in grazing areas. Eggs can also be spread from dog faeces over large areas, predominantly by flies.

The best practice for dog health and sheep measles is for all farm dogs to be treated monthly with cestocidal (tapeworm) drugs containing the ingredient praziquantel — a cheap and effective treatment — and an “all wormer” every three months.

All dog owners, such as hunters or farm visitors who take their dogs near farmland or where sheep graze, should also dose their dogs every month because the tapeworm has a short life cycle and dosing three-monthly is not enough to stop the parasite from spreading.

Any visiting dogs should have been dosed at least 48 hours before going on-farm.

For more information or to view the C. ovis prevalence map showing data for all regions, go to www.sheepmeasles.co.nz.