He has an under-developed top jaw, which means his bottom teeth protrude over his lip

Andy Macmillan, RSPCA

Andy Macmillan, deputy manager of the William and Patricia Venton Animal Centre in St. Columb Major, said Yogi was getting so depressed in a cage he has gone off his food.

He told BBC News Online: "We wouldn't describe Yogi as ugly, but he is probably the most unfortunate looking dog in the country.

"He looks like he is constantly growling because he has an under-developed top jaw, which means his bottom teeth protrude over his lip.

"People take one look at him and say 'I don't want that one'. They say he's ugly, but he is great with people and other dogs."

Re-homed once

Mr Macmillan said dogs are normally at the centre for only four weeks before they are re-homed.

Staff have known Yogi for two years and have already re-homed him once, when he was called Zeus.

"He came from a family who couldn't cope with him anymore, he was just too big.

"The parents were concerned he might squash their children," said Mr Macmillan.

Hundreds of calls

The centre still gets letters from as far afield as Australia about what happened to Felix the cat, after the previous appeal.

"The response to that appeal went global, we had 172 calls in one day about Felix alone, when we normally only get 50 calls a day about all our animals," said Mr Macmillan.

"We even managed to raise �1,000 from donations that came in because of it."

You can call the William and Patricia Venton Animal Centre on 01637 881455.

Have you got an ugly dog? E-mail BBC News Online with the details and picture.