DOG owners are being warned to watch out for a "potentially fatal" substance on beaches.

Newhaven Coastguard is urging dog walkers to be vigilant after reports of a white substance, which could be palm oil, washing up on beaches in Seaford.

Deposits of palm oil, which look very similar to white pebbles, can make dogs very ill if ingested, causing vomiting, diarrhoea, and severe dehydration. In extreme cases it has been known to cause pancreatitis and lead to dogs being put down.

Last summer there were reports of palm oil lumps washing up on beaches in Cornwall due to pollution.

Although palm oil itself is a degraded edible oil, it is thought that other substances mixed in with it, such as diesel from ships, are what can make it toxic for dogs.

Newhaven Coastguard said: "The are many reports on local social media of a substance that is similar to, or is palm oil, on Seaford and surrounding beaches over the last few days.

The Argus: The lump in the middle is a pebble, but the other two are lumps of palm oil. Photo: Newhaven CoastguardThe lump in the middle is a pebble, but the other two are lumps of palm oil. Photo: Newhaven Coastguard

"Please be vigilant. Dogs are attracted to this substance but if ingested it can be fatal.

"If you believe your dog has ingested it contact your vet urgently.

"Report any sightings to Lewes District Council, Environmental Health.

"Please inform you dog walking friends.

"In a coastal emergency please call 999 and ask for the Coastguard."