Dog owners are being warned to keep a very close eye on their pets while out walking as the UK grapples with its biggest outbreak of avian flu, which is now circulating heavily in sea birds.

Bird flu, says the RSPCA, is becoming a serious problem this summer with high levels of disease and mortality particularly in wildlife around the coast, with some reports of the virus also now being found among both seals and foxes.

While the risk to pet dogs from avian influenza is usually very low, it has prompted a warning to dog walkers to be extra cautious around wildfowl, including advice to stick to footpaths and use leads where there are large numbers of birds in order to reduce their animal's exposure to creatures which could be infected.

A spokesman for the RSPCA said: "Avian influenza (AI) is primarily a disease of birds, though there have been reports of highly pathogenic AI in seals and foxes, so bird flu can cross into other species.

"As some dogs may be attracted to - and pick up - dead or dying birds, the RSPCA always recommends keeping dogs under control around wildlife. Although the risk of your dog contracting AI is extremely low, your dog could become contaminated and spread it to other areas. Also dead and dying birds could carry a range of other diseases which might present a health risk to your dog."

Latest Defra figures have confirmed 102 cases of bird flu in England - albeit the exact numbers among wild animal populations are more unclear.

Some restrictions for those housing chickens and other captive birds were lifted at the start of May - releasing wildlife back to outdoor spaces or enclosures - but the outbreak has continued to spread among wild birds which the RSPB says is now having a 'devastating impact'.

Jim Wardill, RSPB England operations director, said: “Bird flu is having a devastating impact on our seabirds – a population already under huge pressure from human impacts including climate change, lack of prey fish, deaths through entanglement in fishing gear and development pressure."

The scale of the outbreak has also prompted RSPCA centres to stop accepting sick gulls because of the risk - a decision the charity has described as 'heartbreaking'.

Alongside limiting the contact dogs may have with potentially infected poultry or waterfowl - either by playing or picking up a sick or dead bird - there is also a concern domestic pets may spread the virus further either on their coat or by stepping through infected bird poo and transferring it.

The Department for Food and Rural Affairs also advises bird keepers to also take precautions to minimise the risk of their pet - dog or cat - carrying the virus on their paws or the fur of their coat from the environment into bird keeping areas, that would then risk infecting their poultry or other animals. While cats and dogs should also not be allowed to feed on infected, or potentially infected, raw poultry or waterfowl.

With weeks of summer ahead, and a lengthy spell of hot dry weather forecast, that may draw more people to coastal spots, Kent County Council is among those advising dog walkers to be extra vigilant.

A KCC spokesperson said: “Avian flu is currently impacting the wild bird population in Kent. The advice to members of the public is that if you find any dead wild birds, including gulls, swans, ducks, geese or birds of prey, in any location across Kent and Medway, do not touch them and report it to your local District or Borough Council for clearance.

"Please keep a close watch on your dogs in gardens and public spaces to ensure they are not touching or picking up sick or dead birds. Keep to footpaths and keep dogs on a lead in areas with large wild bird populations.

"Avian flu is primarily a disease of birds that circulates naturally in the wild bird population and the UK Health Security Agency (UKHSA) says the risk to human health is very low while the Food Standards Agency (FSA) assures properly cooked poultry and eggs are safe to eat.”