An urgent warning has been issued to dog owners after poisonous vegetation was washed up in recent storms.
One dog has already died after eating vegetation near the shore in Cardross yesterday.
A spokesperson for D W Craig vets in Helensburgh said the material was highly poisonous and the dog had died within 20 minutes.
A second dog had suffered fits but was now hoped to be recovering.
Police have not yet confirmed what is responsible and Argyll and Bute Council staff are investigating.
In the meantime dog owners are advised to avoid any areas where material has been washed up by the recent high tides.
A council spokesperson said the issue was being investigated by environmental health officers in Helensburgh in conjunction with amenity services and Police Scotland.
“The area affected is Cardross shoreline and the plant appears to be established rather than being washed ashore. Investigations are ongoing,” she added.
UPDATE: The plant has now been identified – see the more recent story here.