It is one of the greatest joys as a dog owner - taking your pet for a run on a beautiful beach and paddle in the waves.
But since the death of a golden retriever after a visit to north Norfolk, owners say they are being more cautious about letting their dogs enjoy their freedom along our coastline.
Julie Thomas' retriever Hattie died within an hour of eating a fish which had washed up onto the shoreline at Cley on December 31.
The Environment Agency took samples of fish from the beach to be analysed by the Centre for Environment, Fisheries and Aquaculture Science (Cefas) in Weymouth and the results were revealed yesterday.
A spokesman said: 'One starfish was found to contain naturally occurring toxins. The results have been shared with North Norfolk District Council.'
He added that as the beach and the sea are natural systems they always advise keeping pets under supervision to minimise the chances of them coming into contact with or eating anything that has been washed up.
Ms Thomas and her family were walking three of their golden retrievers on Cley beach on New Year's Eve when Hattie ate a dead fish. And less than an hour after leaving the beach, she was dead.
Her daughter Chloe said: 'As we walked along Cley beach, we noticed quite a few dead fish and star fish. A few times the dogs picked them up and we told them to leave them alone - but Hattie quickly ate one before we could stop her.'
The family said they initially didn't think too much of it. But after driving from the beach to Langham, they opened the boot and realised Hattie had died.
Miss Thomas said: 'We were so shocked and upset to lose her. It must have happened within 60 minutes of being at the beach.'
Ms Thomas said: 'We are very keen to get it out there to other dog owners, but we don't know what caused it yet. The toxicology report is still going on, and it is being looked into at government level.'
The Norfolk Wildlife Trust confirmed at the start of the year that a dog had died following a visit to the north Norfolk coast.
They echoed the recommendation to dog walkers to keep animals under close control on the beaches and not to allow them to eat anything washed up on the shore.
And in the following days other owners also reported illnesses in their pets after walks on beaches in the area.
Doug Thompson, 60, took his labrador, Tobie, for a walk from Burnham Staithe towards Holkham on Sunday, January 1. Tobie became seriously ill after ingesting a few small flat fish.
Mr Thompson, who has a degree in marine biology, said: 'The beach was strewn with small green sea urchins and the 12-legged Solaster starfish,' adding that he had never seen anything like it before.
And Zelda Eady, 56, walked her six-month-old black Labrador, Phoebe, on Holkham beach on January 1. Phoebe also ingested a flat, washed up fish.
She said: 'She ate one and luckily my husband took the second one out of her mouth. I am glad he did as I don't think she'd be with us now if she'd eaten more. We did expect her to be sick but not this poorly.'
Dog walkers at Wells on Tuesday expressed their concerns over the risk posed to their pets by any potential contamination.
South Raynham couple Kim Hollingsworth, 29, and fiancé Seamus Dunne, 31, were walking 10-year-old patterdale-x-bedlington Bella, and Spanish rescue Trixie.
Miss Hollingsworth said: 'It is a real worry. We won't go on the beach now, we'll just walk in the woods. I think many people are trying to avoid the area.'
And retired company secretary Jo Cook, in her 70s, was walking her four-year-old black labrador, Boris. She said: 'You do just have to keep a very close eye on them, as it is worrying. Being a labrador, he has eaten starfish before and there's never been a problem. It's just not letting them run off out of sight.'
She added: 'We do have a real problem with the environment and pollution. Just look at this beach, which couldn't be more beautiful. If dogs are getting sick here it is very worrying.'
A couple from a village near Wells, who asked not to be named, were walking their 10-year-old golden retriever Maestro, a two-time winner of Crufts.
They said: 'We do keep a close eye on him when we're walking on the beach. We've heard from other dog owners and vets that it might be palm oil causing the sickness, which is toxic to dogs. It is a concern, and we are keen to hear the outcome of the autopsy.'
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