Footrot
Control
When conditions are green and pasture is growing, controlling the expression of footrot is the best option. The objective is to limit production losses and reduce the prevalence of sheep with footrot. Control is best achieved with either foot-bathing, vaccination, or a combination of both, depending on labour resources and the severity of the strain of footrot. Control continues while conditions are green. Benign strains may not need control except for occasional foot-bathing in wet years.
Eradication
If virulent footrot is diagnosed on your property, eradication is an important priority. The first objective is to eliminate potential sources of re-infection. It is not worth trying to eradicate benign footrot. Two broad options exist for eradication: total destocking and replacement with footrot-free sheep or inspection and culling of all sheep with abnormal feet when conditions are dry. If high numbers are infected, initial salvage of infected sheep may be warranted. After a few inspections during the non-spread period, mobs should be quarantined and, once all sheep have spent a spring with no evidence of footrot, you can be confident that footrot has been eradicated. Always seek advice on footrot diagnosis and management from an experienced animal health adviser.
Ovine Johnes disease (OJD)
Control
If OJD has been diagnosed on your property, management options are available to limit the impact of the disease. The main option available is to use Gudair® vaccine to help control the disease in your flock. Initially, if the prevalence of OJD is high, identify and remove high-risk sheep to help reduce high death rates, and minimise stress due to worms and poor nutrition whilst flock vaccination takes effect. The other important issue is to minimise the risk of spreading OJD to other flocks. Ensuring boundary fences are 100% stockproof is important to limit the spread. In addition, run low-risk sheep in boundary paddocks. Most states have assistance programs to help sheep producers develop management plans to control OJD. Seek advice from your veterinarian or state government veterinarian. Information is also available from AWI:
www.wool.com.au/Publications/Animal_health_and_welfare/page__2206.aspx
and MLA: www.mla.com.au/TopicHierarchy/InformationCentre/TipsandTools/Animalhealthandwelfare/default.htm
Lice
Control
If lice are detected in your sheep during the year, control of fleece damage by jetting may be necessary before shearing. Several chemicals are available for lice control. The choice depends on the time before shearing as wool withholding periods must be observed. Effective control will only be achieved if you follow recommended dose rates and application techniques. The most effective control will be achieved by using correct jetting technique. Guidelines for jetting and dipping can be found at: http://www.agric.wa.gov.au/content/pw/ins/ap/l/fn050_2003.pdf.
Eradication
Eradication of lice will only be achieved if all sheep are treated at the same time, correct dose rates used, and either a backline or plunge dip correctly applied. Ewes must not be treated within 8 weeks of lambing if a backline dip is used. Seek advice about application technique and eradication from an experienced veterinarian or animal health officer. If no lice infested sheep are introduced and boundary fences are 100% stock proof, you will never have to re-treat sheep once lice have been eradicated. This will be a major cost saving, as well as reducing residues in the wool clip.
