By Ian Lewis
Pet owners are being warned about globules of rancid fat washed up on beaches after a dog had to be put to sleep after eating some.
Bright white lumps of decomposing fat, looking like snowballs, have been washing up in small quantities along the Welsh coast for at least a fortnight.
Experts are at loss to explain where it originated but speculate Atlantic storms could have washed it over to the UK or passing ships dumped it at sea.
Digestive system unable to cope
While posing no risk to people the fat can cause potentially serious problems for dogs whose digestive systems are unable to cope with the rancid matter.
Concerned experts with Natural Resources Wales (NRW) are warning dog walkers using the region's beaches to be "vigilant" after a dog had to be put down at the weekend.
Surfer Daniel Hart, 32, from Gorseinon, near Swansea, was forced to put his dog Maisey to sleep after she ate a quantity of what is believed to be congealed vegetable oil.
He had been surfing at the Llangennith beach on the Gower Peninsula, near Swansea, on Sunday when his pet was taken ill, he said.
"I was surfing and Maisey was around the high tide line. I called her to me. She ran half way to me then started being sick," he told BBC Wales online.
Bleeding from the nose
Maisey bled from the nose as she was carried to his car and was quickly taken to an emergency vet where she was given antibiotics for pneumonia.
He took her home and slept with her on his settee but she failed to improve and blood began pouring from her nose.
Less than six hour after the dog had eaten the fat Mr Hart decided it would be better to have Maisey put to sleep.
"It was horrible taking the decision but I didn't want her to suffer. She had lost the will to live."
First reports of rancid fat on beaches
A spokesman for the NRW said the first reports of rancid fat on beaches in Wales had come in from Ogmore, in the Vale of Glamorgan, almost two weeks ago.
"It appears to have started off in the east and is gradually making it's way west," he said.
He said he believed that there had been one death and up to 10 cases of dogs getting ill after eating rancid matter in the Cornwall area as well.
"There is nothing particularly to worry about environmentally and there is no danger to humans - I'm assuming that nobody would try to eat it."
Snowballs of fat are tested
He said that the fat had been tested and found to be largely vegetable matter, possibly oil, that was relatively harmless.
"We are not talking about large amounts here but it is something that dogs might eat so we have warned people to be vigilant for the sake of their pets."
A spokesman for Swansea County Council said that it would investigate reports of the fat but had so far encountered nothing.
He said cleaning the beach would be the responsibility of the landowner in the area affected, which might be the council, the National Trust, the Countryside Council for Wales or a private owner.