THE barber's pole worm is not usually a common occurrence on Victorian farms, but experts say this year this will be different.

Project leader of the Lamb and Kid Mortality Surveillance Project, Dr John Ryan, said he had noticed the increasing numbers of barber's pole worms during his field research.

Dr Ryan said the different climatic conditions over the past two years had produced two diverse sets of data.

"If you look at the first year (2010), internal parasites were not a big problem," he said.

"This year, with the wet conditions over last summer, barber's pole worm has been rife.

"Every second lamb case you were looking at had barber's pole worm infections.

"I don't think we have seen numbers like this in about 10 years."

Dr Ryan said temperatures needed to be over 22C and conditions moist for barber's pole to really take hold.

"If those conditions persist for some time then the eggs survive on the pasture and you have quite a rapid pick-up," he said.

"Winter has helped the situation somewhat, but if we have a wet December and January then we are going to see another surge in barber's pole."

Anaemic-looking animals were one of the key signs of barber's pole, along with extreme weight loss, he said.

"If you think you are facing a worm problem then the best thing to do is ascertain what worm it is," he said.

"But drenching alone will not fix the problem.

"You need a complete worm management plan that takes into consideration drench resistance, good pasture management and regular worm-egg counts."

Dr Ryan also urged farmers to report lamb and kid deaths as soon as they occurred to prevent further stock losses.

Benalla parasitologist Tricia Veale said many farmers in the northwest of Victoria had been hard hit by worms this year, including the deadly barber's pole.

"Some other parts of the state have fared better where it has been dryer, but up here the rain has caused the worms to go berserk," she said.

Ms Veale said farmers needed to check for drench resistance more frequently if they wanted to properly manage worms.

"They absolutely need to test for drench resistance as, in my experience, most farmers will simply go buy the drench that the well-meaning guy in the store recommends for them," she said.