The shop, which raises money for multiple sclerosis, relies on donations of goods being left on the op shop's verandah.

But instead residents are using it as a dumping ground for items such as dirty nappies and broken, filthy furniture covered in cobwebs and excrement.

Manager of the MS Shop, Daylesford, Susanne Thomas said volunteers were taking trailer loads of rubbish to the tip at least twice a week.

"That's $56 worth of garbage twice a week, which is coming out of profits she said.

"One of the ladies opened a bag of donations and there was a pair of mens jeans _ they'd had a bowel movement in them. They'd rolled them up and put them into the donation bag.

"There are so many filthy instances you couldn't imagine."

Ms Thomas said although rubbish dumping had always been a problem for op shops, the situation had been getting worse.

"I don't know if it's because tip fees have gone up or just laziness," she said.

"The other day the verandah was so full of stuff I couldn't get into the shop."

Ms Thomas has put out the call for residents to "donate, not dump."

Donations needed to be items a person would accept for themselves, or not be embarrassed to give a friend.

Of every dollar raised by the MS Shop, 91 cents goes to support and research for MS.

But Ms Thomas said it was as much a community service as a fundraiser for MS.

"We're keeping our prices reasonable. Most of our prices are between four and 10 dollars," she said.

"We don't want donations to stop coming."