What is billed as the biggest dog swim event in the UK has begun with “complete doggy mayhem” as 150 golden retrievers took over a Sussex lido, organisers have said.

The Dogtember event began at Saltdean Lido in Brighton, East Sussex, on Saturday, with the morning “Gold Rush” session filled with golden retrievers and their owners cooling down in the hot weather.

The swim sessions for furry friends began with two slots in 2017 at the art deco venue and has since grown to 40 sessions over September this year.

One of the directors of Saltdean Lido Community Interest Company (CIC), Deryck Chester, said: “Saltdean Lido is a really beautiful venue … We have dogs coming over from all over the UK, dogs coming from Blackpool, Manchester, dogs coming over from the Isle of Wight, with their humans.

“It’s completely bonkers but we have probably about 8,000 dogs and humans coming for these four weekends of the Dogtember event.

“It’s complete doggy mayhem. The great thing about this event is everyone’s smiling. You do get a bit wet but it’s just a bit of fun.”

Stalls for dog treats, toys and more also lined the grass alongside a splash zone and paddling pool where pooches can even take turns down the slide.

Mr Chester said these dog swimming events are fundraisers that help contribute to the sustainability and restoration of the lido and subsidise swims for humans throughout the season.

This year is on track to bring in £60,000, while it is estimated around a quarter of a million pounds have been raised since the events began in 2017.

He added: “We’re very lucky we’re having a heatwave at the moment. It’s a great way for the dogs to cool down.”

Among those joining their dogs in the pool on Saturday, Jen Wise, Lizzie Vine and Penny Wright had travelled from Eastbourne with their goldies Ted and Kenny, who are celebrating their 10th and first birthdays respectively.

Ms Wise said: “It’s our first time here. It’s our dog’s first birthday, it’s a birthday party really.”

Ms Wright said: “It’s crazy. It’s really well organised. Dogs can run about, it’s great and they brought the sunshine.

“The fact we can get in with the dogs, it’s lovely.”

Of the 20 volunteers helping to steward the events over the month, Eia Andersen travelled from Denmark to support the dog swims while timing it in with her UK holiday.

Having previously volunteered a few times, the 42-year-old said: “They’re all great fun, it’s been a lovely time guarding the door (from) the escape artists.

“The interaction between the dogs and their owners having fun by the pool in a controlled environment, the dog is safe, you’re safe, you don’t have to worry about currents like you do on the beach.”

She added: “The community around the lido, all the volunteers are very friendly people.”

Founders of the Kent and Sussex Golden Retriever Club, Millie Goad and Donna Sherlock, were also enjoying the sell-out event having organised at least 100 members to turn up for the dog swim social.

“Dogs just bring people together. (It’s) so sweet. Everyone loves a dog and everyone loves a golden retriever,” Ms Goad, an owner of four golden retrievers, said.

“I don’t think this will ever ever stop. Can you see a single face that isn’t beaming?”

Ms Sherlock, who runs a DIY dog wash business, added: “Dogs have led me to completely ditch my entire lifestyle. I was a head chef and now this is me.”

Dogtember continues to run until October 1. Find out more here.