This region generally has winter-dominant rainfall, mostly greater than 500 mm. The area covers most of Victoria except for (a) the drier north-western area (Mallee and northern Wimmera) to the north or west of Kaniva, Warracknabeal, Charlton and Cohuna, which are in the WormBoss Rangelands (pastoral) region, and the coastal area between Melbourne and the NSW border, which is in the East Coast region.
The more uniform- and summer-dominant rainfall areas of Gippsland may also find the WormBoss NSW central, southern and south west program a useful reference.
These boundaries are approximations only as seasonal temperature and rainfall variations affect worms.
The most important roundworms in this region are:
o Black scour worm Trichostrongylus vitrinus / Trichostrongylus colubriformis
o Small brown stomach worm Teladorsagia (Ostertagia) circumcincta
o Thin-necked intestinal worm Nematodirus spp.
In specific areas in some or most years: the west coast of Victoria, some of the south-western edges of the state including up the border to Edenhope, coastal areas of East Gippsland, irrigation areas such as the Goulburn Valley and Pyramid Hill and extending further into the state in particularly wet years:
Very wet years generally cause higher burdens of all worms. These can be fatal without scouring occurring.
Liver fluke (Fasciola hepatica) is an internal parasite that occurs in parts of this region depending on the distribution of the intermediate host snail, Austropeplea (Lymnaea) tomentosa. 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 life cycle differs from the simple lifecycle of roundworms, so control strategies are different.
This program relates to roundworms. To control liver fluke, see Liver fluke control.