Animal experts are warning dog owners to learn how to spot the tell-tale signs of a killer parasite which is spreading at an "alarming rate" around the UK.
Lungworm, a potentially fatal infection for dogs, has become increasingly diagnosed by vets, the Be Lungworm Aware campaign has warned.
A spokesman said 37 per cent of vets in the UK have diagnosed at least one case of the parasite in 2010 compared to only 16 per cent in 2008.
Vet Luke Gamble said: "Once a problem seen only in isolated areas, lungworm is spreading at an alarming rate in the UK.
"While dog owners are becoming more aware of lungworm, there is still a real lack of understanding as to the warning signs associated with the condition and how to prevent or treat it."
Dogs become infected with lungworm after eating common garden slugs and snails carrying the larvae. A spokesman for the campaign said an infected dog may have breathing difficulties, be lethargic and cough. Other signs include weight loss, fits, reduced appetite, vomiting, diarrhoea, weakness, paralysis and persistent bleeding from minor cuts.
Sarah Wright, editor of Your Dog magazine, said: "While lungworm poses a real risk to all dogs, it can be easily treated if caught early enough and with new advances in veterinary medicine, even prevented.
"With the increasing number of reported incidents, it is more important than ever before that owners are aware of the signs to look out for."