Dog owners are being warned over a mystery illness that has caused a number of pets to fall ill after visits to beaches.
The mystery illness is said to cause vomiting and diarrhoea in pooches, with some reports that the bug has even been fatal.
Very little is known about what is making the dogs unwell after cases were first linked to beaches in Yorkshire and the North East of England before spreading inland.
One expert believes he has the answer to why hundreds of animals have been left sick and dead crabs have washed up on beaches.
David McCreadie, a former senior lecturer in marine biology and oceanography, believes dredging could be to blame.
He believes the process unearthed historical toxins which he is "certain" is responsible for the crab and lobster deaths - and could even causing the sickness in dogs.
"I am 99.9 percent certain that this week-long dredging operation unearthed some historical toxins," Mr McCreadie told Teesside Live.
"It dumped the spoil about three to four miles off - fishermen found hundreds of dead seabirds floating at the site.
"We have asked Defra to take samples from the dredged area and the recent animals and if necessary send samples to Porton Down for analysis specifically cyanide and dioxins.
"As we all know the Tees has been an industrial sewer for 100 years."
However, the Environment Agency has ruled out dredging as the cause of the dead crustaceans.
It comes after the British Veterinary Association issued advice for concerned pet owners after a spike in cases of gastroenteritis-like symptoms.
Where are dogs becoming unwell?
On January 22, Newcastle's Chronicle Live reported that many dogs had fallen ill after trips to the beach in the area, although it doesn't seem that it is only pooches from the North East being affected.
Looking south, down the east coast to Middlesborough, Teeside Live reported that dogs in Redcar and Whitby have been falling ill after trips to the seaside.
Reports are now coming in that dogs across the country including Humberside, Devon, Cornwall, the south coast and London are all falling ill, although the cases further inland haven't yet been linked to those in the north.
What is the mystery illness?
It's still not known what the mystery illness is, with experts urging pet owners not to panic.
Speaking to BBC Radio 4’s PM programme on Friday, BVA President Justine Shotton said that there was not enough evidence on the reasons for the spike in cases or any possible links to beaches.
Dr Shotton said: "We are aware of a recent spike in cases of dogs falling ill from gastroenteritis-like symptoms in several parts of Yorkshire and North East England.
"Vets see gastroenteritis cases relatively commonly in practice, but numbers seem to be increasing and more widespread than usual."
Vets and experts still don't know what is causing the illness and there is currently not enough evidence to link it to certain beaches.
"At this time, we can't speculate on what might be causing the symptoms, and there is currently no evidence to suggest a direct link between the illness and the dogs visiting the beaches," Dr Shotton added.
"We’ve heard reports from vets in the area who are really far inland and they are also seeing an increase in these kinds of cases in dogs that have never been to the beach, so I’m not sure yet if we have enough information to make that link."
Should you be worried?
The British Veterinary Association advised owners not to panic and to talk to their vet in case of any concerns.
“With gastroenteritis, most cases are mild, but some dogs may need hospitalisation with a drip. In the worst situations, it can become haemorrhagic leading to secondary complications or even death, but that is very rare," Dr Shotton added.
The vet added that the cases could be linked to seasonal illness in dogs usually seen in colder months.
She said: “While pet owners are understandably worried, the cases may be part of a normal increase in gastroenteritis that vets see during the colder months.
"We saw something similar a couple of years ago, and the latest data from the University of Liverpool’s veterinary surveillance database points to the spike being part of normal seasonal variation at the moment.
“Our advice to concerned owners is to contact their local vet for prompt treatment if their dog shows any signs of illness, such as vomiting and diarrhoea."
Don't miss the latest news from around Scotland and beyond - Sign up to our daily newsletter here
