What is “Sheep Measles”?
It’s the common name given to lesions in sheep and goats caused by Cysticercus ovis ,the cystic or intermediate stage of the tapeworm Taenia ovis. They are seen as hard white cysts either on the surface or deep in muscle tissue. Dogs act as host for the tapeworm.
Why is Sheep Measles important?
While sheep measles does not infect or cause disease in humans, they are considered defects and aesthetically undesirable by local and overseas customers. In addition each year farmers suffer financial loss as a result of lambs being condemned or downgraded for sheep measles.
How is the infection spread?
Dogs become infected by eating raw sheep or goat meat, including the heart, infected with live cysts. A tapeworm develops in the intestine of the dog in approximately 35 days. Infected dogs pass many thousands of eggs in their faeces contaminating pasture grazed by sheep and goats.
How can I stop the spread of Sheep Measles?
Freeze any sheep or goat fed to dogs (-10c for 10 days) or cook meat thoroughly before feeding to dogs, this will destroy any cysts. All offal should be cooked before feeding to dogs.
Dose farm and any dogs going onto sheep pasture to break the life cycle. Dogs should be treated with cestocidal drugs containing the ingredient Praziquantel which kills any tapeworms present. Most tablets such as Drontal, Droncit and Endogard contain 50gms of Praziquantel. This allows one tablet per 20kg of dog body weight. Milbemax tablets depend on dog sizes, Wormicide tablets contain 100gms of Praziquantel allowing one tablet per 40kg of dog body weight. Packet labels should be read to ensure correct dose rates are used.
How long do eggs survive on pastures?
Eggs can survive 4-6 months on pasture and possibly longer if conditions allow
How long do the cysts remain in the meat?
The cysts can remain alive in muscle for 3-6 months or longer in some cases at which time the sheep’s immune kills the cyst which either calcifies or is absorbed by the animal.
Are there health risks associated with eating sheep measles cysts?
There are no risks to your health if you eat a cyst.
What meats can be safely fed to a dog raw?
Meat from horses, rabbits and possums can be fed raw.
Beef / Cattle Meat should be cooked thoroughly or frozen at -10°c for 10 days in order to reduce the spread of Neospora.
I do some home kill, is it alright to feed a few off- cuts to the dogs?
Any sheep/goat meat could potentially contain viable sheep measles cysts that can infect a dog. That is why it is important to freeze or cook any meat before feeding to dogs.
I have one or two instances of sheep measles showing on my kill sheet but I’m on a regular dosing programme, Where are they coming from?
Under certain conditions eggs maybe dispersed up to 10 kilometres. As the eggs radiate outward the density of the dispersed eggs greatly reduces, but low levels of infection can spread widely .
I have seen “Restricted Dog Entry” signs on farm gates and near public access ways, where can I purchase some?
These signs are for farmers who are on a sheep measles dosing programme and can be obtained by contacting Ovis Management or visiting our sites at field days and shows.
I have contactors and visitors who bring dogs when they come to our farm what should I do?
Unless the dog is required for work discourage people from bringing them onto your farm, if they arrive and you have any concerns whether or not they have been treated require them to be kept in a vehicle or dose the dog and quarantine it for at least 48 hours then bury any faeces.
Can you drench or inoculate sheep for sheep measles?
Prevention of the tapeworm in the dog is key to preventing sheep measles. At present there is no cost effective treatment for the cystic stage in sheep.
Where can dog treatment drugs be purchased?
Most veterinary practices sell worming tablets and provide a mail out service to farmers. Rural livestock firms and some local councils also provide tablets.
What about True Hydatids?
True Hydatids (Echinococcus granulosus) was declared extinct in New Zealand in 1992. The last outbreak in New Zealand was in 1992.