WRML. Haemonchosis and Moniezia – pictorial

Having done many (hundreds?) necropsies (‘post mortems’) on sheep, and removed metres of Moniezia from their small intestines, I totally ‘get’ that farmers and others find it hard to believe that the common sheep intestinal tapeworm (Moniezia) is of minimal importance   The segments in the dung are ‘in your face’ as well.

Please note we are not talking about larval cestodes (larval stages of tapeworms eg hydatids, sheep measles) or pathogenic tapeworms found in Africa for example.

Out of dozens of reported experiments looking at the effect of Moniezia on weight gain or scouring in sheep, only one (from NZ) that I am aware of showed any significant effect from treating specifically (using praziquantel) for tapeworms. This one report of course is gold for marketing people in pharmaceutical companies. They might have got 20% or whatever improved weight gains by treating for tapeworms in that one, solitary study, but it is almost certain that your result will be very close to zero (even less if you overlook the important sheep worms).

Treat for tapeworm if you like, but make sure at the same time you are doing a good job on the really important worms, the ones you can’t see so easily.

Many times I have done field investigations where the farmers used a combined tapewormer + broad-spectrum drench product where the tapewormer (praziquantel) probably worked very nicely on the tapes (by the way, there are reports of resistance of Moniezia to praziquantel), but the broad-spectrum didn’t work at all on scour worms because of resistance. Sometimes the lack of efficacy of the broad-spectrum drench was not clinically obvious, but the economic loss (lower weight gains and less quality wool produced) would have been significant   (e.g. equivalent to several dollars or more per sheep per year).

So, don’t major on minors, or, as our American friends might say, ‘don’t sweat the small stuff’.

To keep tabs on the really important worms, you need to do regular WormTesting: worm egg count (WEC) monitoring.   And regularly check drench efficacy by doing a WEC 10 days after the drench (in the case of short-acting drenches).

WECs are one of your best friends.

In NSW, the top worms of small ruminants (and alpacas) are barber’s pole worm (Haemonchus), the scour worms: black scour worm (Trichostrongylus) and small brown stomach worm (Teladorsagia (Ostertagia)), plus liver fluke (Fasciola) in some areas.

Regarding the pics:

Please respect the rights of the owners of these images. Contact them if you wish to use their images.

(I think it would be ironic if a pharmaceutical company, as a result of this WormMail, paid Jim to use his Moniezia pic in promotional material for their sheep tapewormer…  🙂