Introduction

What worm control regions are in Tasmania?

The Tasmanian high rainfall (prime-­lamb) region

This region includes King Island, the North Coast between Wynyard and Launceston. These are the high winter rainfall areas with up to 1200 mm annually.

The Tasmanian medium to low rainfall (extensive) region

This region includes the north-east coast, the Midlands and Derwent Valley and the lower east coast. The rainfall is non-seasonal, between 350 and 600 mm annually.

The Tasmanian summer rainfall region

This region includes Flinders Island and in some years, the north-east coast. The medium to low rainfall region recommendations apply here, but the summer rainfall also predisposes to barber’s pole worms. Also, other areas in Tasmania with sheep on irrigated summer pastures may experience barber’s pole worm burdens in late summer and early autumn.

These boundaries are approximations only as seasonal temperature and rainfall variations affect worms. A map of the regions is shown below.

What worms are covered in this program?

Roundworms

The most important roundworms in Tasmania are:

• Scour worms
  • Black scour worm Trichostrongylus vitrinus / Trichostrongylus colubriformis
  • Small brown stomach worm Teladorsagia (Ostertagia) circumcincta
  • Thin-necked intestinal worm Nematodirus spp

In summer rainfall areas:

• Barber’s pole worm Haemonchus contortus

Barber’s pole worm

In this region, barber’s pole worm is generally sporadic and of short duration, therefore the Barbervax® vaccine is unlikely to be needed or cost-effective compared to 4–6 weekly monitoring of worm egg counts during high risk periods and treatment with a short-acting drench or closantel.

However, if your farm has periods of high barber’s pole worm risk for several months each year (which may occur in coastal areas or on irrigated pastures) seek professional advice as to whether the Barbervax vaccine program should be considered.

Liver fluke

Liver fluke is an internal parasite that occurs in parts of this region depending on the distribution of the intermediate host snail. It can cause deaths from acute infections of immature fluke and Black disease from October to January, or anaemia and ill-thrift from chronic infections (generally January–June).

The lifecycle differs from the simple lifecycle of roundworms, so control strategies are different. This program relates to roundworms. To control liver fluke, see Appendices: Further information on sheep worm control for Tasmania.

Other worms

Gastro-intestinal parasites of minor importance, such as stomach fluke and tapeworm, are not covered.