Palm oil has found on more beaches in Sussex and dog owners are advised to be cautious and keep their pets on a lead.
Palm oil has been found across beaches in Adur and Worthing after lumps of the waxy sulphur smelling substance were found earlier this month in Shoreham and Brighton.
Palm oil is non-toxic to humans but can both poison and choke dogs.
The Veterinary Poisons Information Service said the main problems caused are vomiting and diarrhoea and these can lead to dehydration, particularly in young or small dogs.
A spokesman said: “There is also a potential risk of pancreatitis which can result in vague, non-specific signs including vomiting and diarrhoea.
“We would suggest anyone with a dog that has eaten palm oil contact their vet for advice, particularly if the dog is already unwell.
“There is no specific treatment but the dog may need medication to control vomiting and intravenous fluid to treat or prevent dehydration.
“The main thing owners can do is to prevent exposure.”
A spokeswoman for Adur and Worthing Councils said: “Our beach, cleansing and parks teams are monitoring the beaches for palm oil on a daily basis.
“If you find some palm oil please report it to the beach office.”
To report it call 01903 238977 or email beach.office@adur-worthing. gov.uk