NSW WormBoss Worm Control Programs
NSW WormBoss Drench Decision Guides
The drought continues; the hot, dry weather is keeping internal parasite burdens low based on worm egg counts performed in the Coonamble district lately. Flock numbers are well down on normal years as destocking continues.
Flystrike remains a potential issue, although less of a risk post-Christmas due to absolutely no storm activity. Small black flies are worrying sheep, cattle and companion animals, and increasing the incidence of pink eye in livestock species. Producers are reminded that the causative bacteria of pinkeye, and therefore treatment regimes, differ between sheep and cattle, and advice from a veterinarian should be sought to devise the best possible treatment and prevention strategy.
Numbers of ticks have recently been found on all species of host—cattle, sheep, dogs, horses and wildlife. Identification of the tick species involved is warranted to ensure that paralysis ticks or cattle ticks have not crept into our area. Producers can contact their LLS office for advice on identification and prevention strategies.
Things have been quiet in the Forbes area, and very few worm tests have been conducted. The extremely hot and mostly dry conditions are significantly affecting larval survival out there on the ground.
Producers are advised to conduct a worm test before giving a routine summer drench. A drench may not be required if worm counts are low, and in fact, may do more harm than good by potentially increasing drench resistance on your property if the drenches to be used are not 100% effective.
Sheep grazing those patches in the district that received summer storms will need to be monitored for signs of barber's pole infection—weakness, maybe 'bottle jaw', and possible death. Barber's pole does not cause scouring.
Sheep producers have been completing WormTests over the last month in response to summer storm activity. While test results have returned very low worm egg counts, sporadic summer rains and heat could now favour a build-up of barber's pole burdens in particular.
Sheep producers should continue to carry out regular WormTests on all mobs to help determine if a drench is required.
The time for summer feed to grow and become winter standing hay is rapidly disappearing.
The low condition score of ewes for joining is worrying, but fewer twins might be a good thing at the end of next winter if pasture condition continues to be poor.
There is no doubt that the recent scattered showers will prove to be a boon to barber's pole eggs up here. The short grass and heat will have reduced pasture contamination, but the occasional rain will have created wonderful conditions for hatching and reinfection. There were some showers a few weeks ago that would have supported larval infection of sheep, and these larvae will now be adults and churning out large numbers of eggs. The extensive rains of the last few days will encourage this resurgence, but many producers may have forgotten about worms because of the previously dry conditions.
The few cases of ‘worms’ I have seen have shown some very significant worm egg counts.
While limited, WormTest submissions from the Albury-Holbrook region over the past month have shown low to moderate worm burdens. One mob of Merino wethers had a worm egg count of 300 eggs per gram (epg), but worm typing was not carried out. On another property, mobs of Merino ewe hoggets and maiden Merino ewes had counts of 132 epg and 272 epg, respectively. The latter count contained a worm population of 17% barbers pole worm, 57% black scour worm, and 26% brown stomach worm. Some Merino wether lambs had a worm egg count of 100 epg, and a mob of SAMM ewes recorded 220 epg. All eggs reported in all tests were strongyle-type. There haven’t been any reports of significant losses due to worms.
The unseasonal and isolated summer rainfall experienced across parts of the region over the past few months has had the potential to promote scour worm activity, and particularly barber’s pole worm activity. A few weeks of dry heat wave conditions may abate this slightly; however, it would be wise to continue to monitor with WormTests. Considering the weather pattern, and that there is some evidence of moderate worm activity in the region, benefit will likely accrue from summer drenching.
Flystrike appears to be moderate, following preventive actions already taken on farm.
There has been a recent case of coccidiosis in the western part of the region. Coccidiosis may affect sheep and cattle and is caused by the protozoa Eimeria spp, a microscopic parasite that lives in the intestinal tract. Coccidiosis results in profuse scouring, which, in severe cases, can result in death. While normally present in low numbers in sheep, especially lambs, the parasite can proliferate when young susceptible animals are confined on damp soil or at high stocking rates—such as in a feedlot or weaning situation. As the spread of infection is from eating feed contaminated with faeces containing Eimeria, trail feeding on the ground when conditions are damp can be an added risk factor as it allows for easier faecal contamination than trough feeding. The condition is often seen in conjunction with other stress factors for lambs such as a high worm burden or nutritional stress. Moving animals to clean ground and fixing any concurrent issues is usually curative, although treatments are available if warranted in the circumstances. Sheep tend to develop good immunity to coccidia after infection.
Increased testing for liver fluke occurred this month in both cattle and sheep. Most of the cattle were tested with the pooled blood tests, and have been positive. These tests are a valuable and accurate way of assessing fluke levels in stock, and the efficiency of your fluke control program. Consider asking your District Veterinarian to assist with surveillance for fluke on your property, or ask your private veterinarian to collect samples for you when they are pregnancy testing. Clinical signs of fluke at this time of the year can be weight loss, bottle jaw, anaemia and even death.
Summer rainfall and grazing short green grass have caused recent increases in worm egg counts of both barber’s pole and the thin-necked intestinal worm, Nematodirus. The best tool for maintaining control of barber’s pole worm is 4–6 weekly worm egg count monitoring, and continually checking for signs of anaemia or weakness. The recent run of temperature extremes of over 40°C would have significantly controlled worm larvae and eggs on pastures, but beware of the areas where sheep are crowding onto short grass or grazing into soaks where the grass is green. Barber’s pole infections in stock can build up very quickly under these conditions. When assessing the need to use a long-acting drench look carefully at the pasture conditions, and seek veterinary advice. (Editor’s note: Long-acting drenches are best used when the season is wet, grass cover is good, and levels of refugia are high).
Nematodirus numbers in sheep have increased following the recent rainfall events inducing the hardy, dry-tolerant eggs to hatch into larvae and contaminate the short green pick. In some cases, this has resulted in scouring of weaners.
Coccidia oocyst counts have also increased, generally reflecting trail feeding of young weaners on the ground during summer rains. Producers are encouraged to be ‘on the watch’ for scours and to contact their veterinarian as there are many different causes for scours other than coccidia.
The worm test submissions received here in Berry and the surrounding areas have been from alpacas. The numbers of worm eggs present in these alpaca herds have ranged from zero to very low.
With the increasing temperatures and humidity, livestock producers are reminded to reduce the impacts of heat stress on stock by ensuring they have access to clean, good quality water. I have seen both cattle and sheep refuse to drink when shifted to new paddocks because the water in the dam or river was too low, of poor quality, or just plain dirty. Consider doing water quality tests on your water sources. Kits are available by ordering online or collecting from your nearest LLS office. Ensure stock have access to shade from tree cover, constructed shelters and/or naturally undulating paddocks and gullies. Handle stock in the earlier or cooler parts of the day.
DPI water quality tests: https://www.dpi.nsw.gov.au/about-us/services/laboratory-services/water-testing/tests-available