The British Veterinary Association said the reports of ‘gastroenteritis-like symptoms’ had sparked speculation that the illness could be linked with visits to beaches.
Common symptoms reported by owners so far – with one case reported on Hayling Island – include dogs being weak and listless, shaking and vomiting.
BVA President Justine Shotton has advised owners not to panic and to talk to their vet if they have any concerns.
She said: “Vets see gastroenteritis cases relatively commonly in practice, but numbers seem to be increasing and more widespread than usual.”
“At this time, we can’t speculate on what might be causing the symptoms, and there is currently no evidence to suggest a direct link between the illness and the dogs visiting the beaches.”
Dr Shotton said the BVA had received reports from vets inland and that they are seeing an increase in cases in dogs that have never been to the beach.
“With gastroenteritis, most cases are mild, but some dogs may need hospitalisation with a drip,” she said.
“In the worst situations, it can become haemorrhagic leading to secondary complications or even death, but that is very rare.”
Dr Shotton added that the increase in cases might be part of a normal increase in gastroenteritis that vets see in winter, saying that the BVA saw something similar two years ago.
“The latest data from the University of Liverpool’s veterinary surveillance database points to the spike being part of normal seasonal variation at the moment,” she said.
Dr Shotton advised owners of unwell dogs to contact their local vets for treatment quickly and urged veterinary practices to report any cases of the vomiting bug to help researchers investigate.