Inquisitive pets could become seriously unwell and even pass away if they run into this danger while exploring the seaside.
Vets have urged people to be vigilant on strolls across the sand as one dog nearly died after ingesting some stray fish bones.
Denver, an adorable cocker spaniel, came across the dangerous snack at a beach in Worthing, West Sussex, and devoured them.
His owner Samantha said her back was turned for just a few moments, but the pup managed to eat them all up.
She explained a side effect of his medication for his epilepsy, which the dog was diagnosed with last year, is that Denver is constantly “ravenously hungry”.
Although he mostly sticks to chewing up cardboard around the house, the pup had taken his snack obsession to new heights.
The fish bones terrifyingly became trapped in Denver’s stomach and refused to budge, much to Samantha’s horror.
It meant her beloved furball was at risk of suffering from a perforated colon as well as toxic shock.
She told the Mirror: “Anything at all he can scavenge he’s in at straight away – including, for some strange reason, the inside tubes from toilet rolls.
“With the fish bone incident, we were at Worthing Beach for our usual walk and he literally bit off more than he could chew.
“He started chewing a lump of compacted fish bones and then spat it straight back out – but what we didn’t realise was that he’d somehow managed to swallow some of it as well.”
Samantha said although he initially appeared okay, Denver’s stomach then “just completely seized up.”
She found him whimpering in pain in the garden and realised he needed to be looked at immediately.
The owner rushed her darling five-and-a-half-year-old pooch to the emergency clinic Vets Now for treatment.
He was hastily put on a drip to ensure he wouldn’t become dehydrated, while vets also gave him some laxatives.
They hoped the medication would help Denver dislodge the fish bones – but they were stuck in an awkward spot.
As the poorly pup grew increasingly anxious, the vets decided to take several x-rays to take a closer look at the troublesome blockage.
Keen to avoid surgery, they then sedated Denver and gave him some stronger laxatives – that managed to move the fish bones along.
Luckily, he was back to his usual excited self just 48 hours later, leaving Samantha relieved.
But experts warned the incident could have easily had a more sinister outcome.
Vet nurse Amy Webster, based at Vets Now Worthing, said Denver was extremely “brave” and the team were delighted at his progress.
She continued: “Samantha did absolutely the right thing bringing him and was incredibly patient, understanding and calm throughout the whole procedure.
“Clogged intestines can have really serious and – sometimes – fatal consequences for a dog.
“Fish bones can be particularly sharp – much shaper, for example, than a cattle bone – and that leads to a much higher risk of essential organs being punctured.”
Dog owners were also warned to keep an eye out for a “toxic substance” found on beaches which killed one pet.