Sheep Measles are small cysts found in the meat of infected sheep and goats.

Cysts are found throughout the meat and only a small proportion are on or near the surface. Cysts are most easily seen in the diaphragm, flaps, heart, jaw muscles and tongue.

Sheep Measles are not a human health risk but are viewed as a quality defect by both overseas customers and authorities.

New Zealand’s ability to gain maximum returns from sheep meat is threatened by product containing sheep measles.

REMEMBER:  All sheep and goat meat should be treated before being fed to dogs.

SHEEP MEASLES LIFE CYCLE

Tapeworm = Taenia ovis

Cystic stage = Cysticerious ovis ( C.ovis )

Common name = sheep measles

Primary host (harbouring the tapeworm) = dog

Intermediate host (harbouring the cysts) = sheep & goats

DOGS become infected with T.ovis worms by eating raw sheep/goat meat or offal infected with C.ovis cysts. These cysts develop to worms in the dogs intestine after four to five weeks. Mature worms shed eggs via the dogs faeces in large numbers (up to 250,000 per day ). Eggs have the ability to survive on pastures for up to six months depending on conditions.

SHEEP become infected with C.ovis cysts by ingesting eggs shed by dogs onto pastures. The sheep’s digestive juices dissolve the egg’s shell and release an embryo which burrows through the intestinal wall and into the blood stream to eventually lodge in muscle tissue.

Four to five weeks after ingesting eggs, sheep develop infective cysts, these are difficult to see or feel.

Each cyst contains a tapeworm head, which if eaten raw by a dog, develops into a T.ovis worm.

About 3 to 6 months after ingestion most of the cysts die. Many of the dead cysts become hard and gritty (calcify). These dead cysts are easier to see, many are detected at meat inspection. However some cysts remain infective indefinitely.

RECOMMENDED FARM PRACTICE

1*    Home killing of sheep or goats, should be carried out in a dog proof enclosure.

2*    Before feeding sheep or goat meat to dogs, treat by either freezing or cooking.

FREEZING: freeze meat to a core temperature of –10 C or colder for at least 7 days.

COOKING: heat to at least 72 C throughout. ( carry out this process in a dog proof area ).

3*    Always treat the head, tongue ,flaps and other off cuts of sheep and goats before feeding to dogs.

4*    Cut up meat in dog proof area (killing enclosure).

5*    If freezing: Date dog food meat clearly to allow identification of meat ready for use.

6*    Check freezer is operating at –10 C or colder.

7*    Use alternative safe dog foods such as dog pellets, biscuits, sausage or meal.

8*    Keep dogs under control when not in use (including pet dogs).

9*    Treat dogs for sheep measles with an appropriate drug in the event of a suspected control breakdown.

10*  Require all dogs entering property to have evidence of treatment with a cestocidal drug.

Discuss the most appropriate control programme for your property with your animal health advisor.

OVIS MANAGEMENT- IT’S YOUR RESPONSIBILITY!

If you wish to obtain a Taenia Ovis Prevention form or have any queries please email us.

INFORMATION SOURCED FROM - Ovis Management Ltd in association with the New Zealand Meat Industry Association.