Public Health Wales (PHW) said although uncommon in Wales, it remained "a significant public health concern because of the potentially serious health consequences for affected individuals".

Dr Chris Williams, a consultant epidemiologist with PHW, said: "It can be very serious for humans. It's caused by a tapeworm, and what happens is normally the tapeworm transmits between farm animals like sheep and cows to dogs, (and) the dogs excrete eggs.

"Unfortunately, if humans ingest the eggs, usually from dogs, that can then form cysts within humans, which are very unpleasant, cause swelling, pain, etc. and require surgical treatment."

He added it can be 10 or 20 years before symptoms appear.

"So we need to address the problem early on at the point where we're starting to find it in dogs and carcasses rather than waiting for human cases."

The tapeworm, which causes the disease, is considered endemic in mid Wales due to the prevalence of sheep farming in the area.

Dr Gwenllian Rees, from Aberystwyth University's School of Veterinary Sciences, is supervising research which will study human-dog interactions and analysis of faecal samples.

Rees said: "It's really important for us to understand the levels of this disease in mid Wales at the moment, the risks to farmers, and the way that this disease is being transmitted or not at the moment in Wales."