Household pets face devastating outbreaks of disease because “anti-vax” scares have pushed vaccination rates dangerously low, a leading veterinary body has warned.

The Federation of European Companion Animal Veterinary Associations (FECAVA) says the UK dog and cat populations are losing their “herd immunity” thanks to conspiracies progated online, in turn threatening owners.

Vaccine scepticism is a growing threat to human medicine, with unfounded fears - for example that of links between jabs and autism - gaining traction since Andrew Wakefield published fraudulent research in the Lancet in 1998.

The theories are endorsed by a number of celebrities, including Robert de Niro and Jim Carrey, and the World Health Organisation ranks “vaccine hesitancy” among its top 10 threats to global health.

FECAVA now believes that the anti-vax movement, fuelled by social media, is pushing pet vaccination rates below the threshold at which small outbreaks of deadly conditions such as Parvovirus and canine typhoid fever can be naturally contained.

The body cites figures from the People’s Dispensary for Sick Animals, indicating that 25 per cent of dogs - roughly 2.2 million - no longer receive a primary course of vaccinations, a rise from 20 per cent in 2011.