Australia's resource for control of worms, flies and lice in sheep,
This month our feature article blurbs have been written by Dr. Paul Nilon, a sheep veterinary consultant and our Tassie correspondent, who is also a member of the ParaBoss Technical Committee. Readers are asked to provide feedback on this style (compared to our very short previous blurbs)—press reply to this email and let us know your thoughts.
from the WormBoss web site, introduction by Paul Nilon
Integrated pest management (IPM) is the grand notion of using a number of strategies, particularly environmental control (grazing management and strategic drenching) to augment worm control. I say “grand notion because in most worm-ridden parts of Australia (the high rainfall zones) it is not done or done poorly, in spite of 50 years of preaching by credentialed parasitologists. Even in the New England where Haemonchus control with therapeutic drenching alone is almost impossible, uptake is not what it could be.
So, here is my pitch for Merino and mixed flock owners to get better winter worm control: set up a smart grazing system. This is the most potent tool we have to provide safe winter grazing for young sheep in southern Australia. Practised diligently, it also reduces the whole-farm contamination profile. Just do it! It needs to be set up right now, not next month. In summer grazing management rainfall regions, a similar process can be done for lambing ewes and lambs being weaned. Ring an advisor for help if required. >> Read more.
from the FlyBoss web site, introduction by Paul Nilon
Some parts of NSW and Victoria have had some rain in the last few weeks, increasing the risk of strike. The October edition talked about the timing of preventive treatments. It’s timely to think about monitoring for strike and what to use when you find clinical cases. You should be monitoring for flystrike regularly, and if you opt not to use a preventive treatment this should be at least twice weekly: more frequently if conditions are high risk, or if the sheep have any dag. Monitoring needs to be systematic: mobs held in the corner of the paddock and inspected closely. Look for signs of irritation as well as visible signs of strike. “Worried” sheep often have covert strikes. One client suggested a drone for monitoring. It may work provided you are not distracted by the sunbathers down by the river.
While linking "how to treat flystrike" is teaching granny how to suck eggs, you would be amazed how many people do it poorly. Take particular note of the need to kill maggots to break the cycle, and put the struck sheep in a hospital mob, ideally for later culling. Finally, the list of treatment chemicals is not huge. Check out the “dressing” column on the link. Apart from efficacy you must consider the wool rehandling intervals and the wool harvesting and export slaughter intervals. >> Read more.
from the LiceBoss web site, introduction by Paul Nilon
In the best of all possible worlds we would only treat for lice when we had a definite diagnosis: your sheep have been in contact with lousy sheep or you found lice on your own sheep. But finding lice is often difficult. Numbers may be low because of the time since shearing, the time since contact with lousy animals or the failure of a previous treatment. Keep this in mind when monitoring for lice: allow 3–4 months after shearing, lice contacts or treatments before you inspect. The inspection process is outlined in this article by Jenny Cotter.
Apart from exposure to a lice risk, suspect lice if the sheep are rubbing. If you cannot find lice ask yourself what are the alternatives? Not so many, but the common ones are given here. Dermo and fleece rot will be familiar to most merino producers, but may be outside the experience of meat sheep owners. Get some professional help. Photosensitivity causes severe discomfort on all bare areas (face, feet, and udders) so look for pronounced irritation of these parts. Wool breaks are most often associated with pregnancy. When all is said and done, if you have rubbing and a known risk, lice are more likely than other causes of rubbing. So, keep looking. And looking. And looking. >> Read more.
from the WormBoss web site, introduction by Paul Nilon
Much of the discussion about worms in goats centres on two things: what anthelmintics are registered (and work) in goats, and the need to provide browse to reduce exposure to larvae. On many farms there is no browse as the goats have killed the trees. Therefore, you are forced to use the range of grazing management tools available for sheep. For decontaminating winter paddocks "smart grazing" works a treat. The thing is that it’s hard to get the grazing pressure from goats to graze down to what’s needed. To get the same grazing management effect with goats you may need to augment the grazing pressure with some judicious slashing or grazing with cattle. >> Read more.
Toxoplasma gondii can cause behaviour changes including (reputedly) nymphomania and risk aversion. Infected rats appear to lose their fear of cats and become easy prey to the cat, which is the only definitive host of this parasite. But almost any mammal, including humans, can be infected as an intermediate host by this single-celled protozoan parasite, which is spread in the faeces of infected animals, particularly cats.
In sheep and goats, Toxo is a cause of abortion, but does not seem to cause disease in cattle.