NSW WormBoss Worm Control Programs
NSW WormBoss Drench Decision Guides
NSW LOCAL LAND SERVICES—District Veterinarian (DV) reports
Counts for the month have averaged from 0–1400 epg. The few larval differentiation results obtained have shown the black scour worm to dominate with the occasional barber’s pole worm result creeping in.
A few deaths have been associated with elevated worm counts, and this has especially been seen in lamb mobs that are to be weaned or have recently been weaned. A prompt and appropriate drench has resolved these issues. Producers have been reminded to perform worm egg count tests prior to drenching to see whether it is necessary or not for the mobs in question to be drenched. A few producers have also begun to instigate their first summer drenches.
Fly strike prevention is well underway throughout the district and common questions asked are regarding effective chemical treatment options and Export Slaughter Intervals for the associated products.
Recent weather conditions in the Wagga Wagga region and removal of stock from cereal crops has seen some reduction in visible sheep scours. Results of worm egg counts have been highly variable. No evidence so far of Haemonchus infections. Rainfall from now onwards will determine if Haemonchus burdens become as significant as last year. With wind-rowing and harvest fast approaching, now is the time to consider worm egg count monitoring. As always, drenching should occur if counts are significant. Repeat testing should be considered in 6–10 weeks in preparation for the first summer drench, a drench that is still considered an important requirement in this area.
In higher rainfall areas within the region where moisture remains high, we have seen occasional fluke burdens. It is important to note that fluke eggs are not easily identified by standard worm tests, but need to be requested when submitting dung for a WormTest. If you are in a fluke area do not hesitate to contact your regional veterinarian for more specific advice in this area.
For those that wean in January, weaner paddocks should be spelled for the October-December period. Despite the dry conditions producers should be monitoring with worm egg counts every 6-8 weeks as some properties will have high worm burdens. There have been a few reports of mixed worm infections with high numbers of scour worms (Teladorsagia and Trichostrongylus) relative to Haemonchus. Dry conditions across the Northern Tablelands mean larval development for Haemonchus will be slowed.
A WormTest at this time is advised. There are variable worm egg counts in the few samples that have been submitted, but it was wet enough in the six months leading into August for plenty of larvae to be on pasture. The dry change will assist in steadying the rise of worm burdens, but a drench may still be warranted, especially in young stock.
In the east this month, we have found a few high strongyle counts in individual sheep with concurrent illness and one WormTest reported low-moderate numbers of strongyle eggs.
In the west, a few worm counts were done, mostly showing a very low level of strongyle and coccidian infections.
Worm egg counts in many lambed mobs continue to show rapid worm reinfection from contaminated paddocks. While black scour and brown stomach worms predominate, a reasonable proportion of barber's pole worms are also present in some mobs. Where faecal samples from ewes and lambs have been submitted separately, worm egg counts in ten to twelve week old lambs are already quite high, carrying a warning not to delay the weaning drench this year.
Weather conditions (warmth; moisture) now suit the survival and hatching of barber's pole eggs, so it would be worthwhile knowing whether you have this worm in your sheep. A worm egg count with culture is the best guide. By way of caution, there have been a couple of recent cases of "infectious anaemia" seen in bigger lambs. This blood parasite (M. ovis) often appears six to eight weeks after marking and mulesing, and destroys red blood cells. It causes pale skin and membranes similar to barber's pole infection. It is worth asking your vet for a post mortem examination to confirm the diagnosis because mustering affected lambs for an unnecessary drench may kill some and not control the infection.
Blowflies are active in winter-drop lambs, targeting any with wet dags. Remember to check the Export Slaughter Interval of any fly control product used as there is a huge variation.
If the number of enquiries from producers regarding lice control is any guide, there's a lot of lice around! There are no shortcuts with lice control. We are lucky to have several highly effective lice control chemicals available, as well as access to experienced dipping contractors, so getting rid of lice should be easy. Not shearing all sheep at the same time, and disregarding treatment to lambing interval accounts for the majority of treatment failures investigated. Seek advice from your vet or chemical company rep, or check out the LiceBoss website.
In the Forbes area the season is well and truly starting to dry off, so now is the time to plan the first summer drench onto clean, dry pastures as they become available. Whereas a drench will almost certainly be required at weaning, it may be worthwhile planning ahead by worm testing first to ensure that a drench is required in older sheep.