A temporary ban - introduced most years - has been implemented before to protect birthing deer. But the 2021 period is twice as long as last year.
The move comes following a number of dog attacks in recent months.
However, thousands of dog lovers, including the British model, who in an ambassador for Battersea Dogs & Cats Home and owns a rescue dog named Dora, have criticised the ban.
Gandy regularly runs with his Yorkshire Terrier, Dora, in Richmond Park and he used Twitter to post support for a petition opposing the new rules, which has already attracted more than 2,000 signatories in just a few days.
He wrote: “Richmond Park have banned dogs off the lead in entire 3,500 acres of Richmond and Bushy park. Yes it is Important to protect wildlife, but has gone from a 6 week ban last year to 3 months in 2021. There are better solutions and punishes responsible dog owners.”
The blanket ban has sparked a social media war with supporters arguing the safety of the deer is paramount.
By contrast, dog owners have criticised it as a “travesty.” Many dog lovers have been driven away from the parks with businesses, such as cafes, in the surrounding area now suffering.
The petition on the Change.org website titled “Allow Dogs OFF leads in Bushy & Richmond Park” was posted by photographer Tamra Cave, who said she accepted this is an emotive issue.
She said there were some 90 reports of dogs chasing deer in the two parks over a year and some five deaths as a result.
Against this, there are 365,000 dog walks in the parks and the authorities cull around 90 deer each year to control the numbers.
“This new regulation is using a sledge hammer to crack a nut,” she said.
“Keeping a dog permanently on a lead in a park is like giving a child a toy and saying you can’t play with it.
“We all need to work together as animal and park lovers to enjoy the park and keep everyone safe - deer, dogs, children, cyclists and runners.
“The deer breeding areas can be marked on maps so as to be avoided and dogs kept on lead around these areas. We have never needed to keep dogs on leads until last year when restrictions were mostly about Covid.”
Louise Rawlinson, who is a dog trainer and runs the dog friendly Paws for Coffee café, in Hampton Hill, just a few yards from one entrance to Bushy Park, said the new rules have devastated her takings.
“The new rules have affected my business immensely. Already, we have dropped by half,” she said.
“Of course, I respect the deer and the rules…but I would suggest that we have an area where the dogs can go into.
“This is going to affect the High Street and if this is going to happen every year – May to August – I don’t know if I am going to survive this.
“There is no support. We don’t know how long we can survive for if they keep putting these stupid rules in.”
Simon Richards, Park Manager for Richmond Park, explained the controls saying; “During the deer birthing season, we strongly advise that dogs are not walked in either Richmond or Bushy Parks but, if this is not possible, dogs must be on leads in all areas of the parks.
“Female deer are afraid of dogs harming their young. Concern for their newborn means they may act defensively towards dogs - they have been known to give chase and attack, even if the dog is at a distance and not acting provocatively.
”Dog walkers must remain vigilant, avoid areas of dense vegetation and stick to the perimeter of the park. As a dog owner myself, I know this can be frustrating, but it really is for the safety of both deer and dogs. We’re sorry for any inconvenience caused and we thank all our visitors for their support with these measures.”
It comes after a man was fined £602 in January after his dog fatally injured a deer during a ‘relentless’ attack in Richmond Park.
Dramatic footage filmed by a cyclist shows Franck Hiribarne’s red setter, Alfie, rushing at the small hind, jumping up at her and dragging her backwards.
The Conservative MP, Danny Kruger, has been charged with allowing his Jack Russell to chase deer in Richmond Park.
The 46 year-old MP for Devizes, Wiltshire, is due in court later this month in relation to an incident that happened in March. He was due to appear on bail at Wimbledon Magistrates’ Court today but the case was adjourned in his absence until May 24.
He is charged that on March 20 at Richmond Park, without written permission from the Secretary of State, he permitted his Jack Russell dog to chase, worry or injure a large herd of fallow deer.
In November, a frightened group of fallow deer nearly trampled a photographer after they were sent stampeding by a puppy which was off the lead.
The dramatic incident was captured by photographer Max Ellis. In September, he took pictures of a small French bulldog confronting a stag.
“I’ve seen dogs chase the deer on many occasions. It’s natural for dogs to chase deer and poorly trained animals find them irresistible,” he said.