Parasite migration signals climate change

July 7, 2008

A parasite that thrives on warm conditions has been discovered in Scotland for the first time, supporting theories of climate change.

Staff from the University of Glasgow’s Vet School identified the parasite Angiostronglyus vasorum, also known as the ‘French heartworm’, in a dog admitted to the Small Animal Hospital. It is thought that the parasite, which is normally found in south west England, could be moving northwards because of increasing temperatures.

Small Animal Hospital Vet Jenny Helm, who treated the dog, said: “A one year old Weimaraner was brought to the Small Animal Hospital suffering from bleeding into the eye and skin. Once we had confirmed the diagnosis we were able to treat the dog with a particular type of wormer and he has now made a full recovery.

However, dog owners and veterinary surgeons should be aware that the parasite has arrived in Scotland. This parasite can cause serious diseases and death is not unknown. If owners suspect their dog may be infected with the parasite they should contact their local vet immediately.”

The clinical signs which signal an animal may be infected with the French heartworm parasite are coughing, breathing difficulties and unexplained bleeding problems, including spontaneous bruising and bleeding into the eye.

Although animals that are infected with the parasite can be treated quickly, the movement of the parasite north could signal more serious problems in terms of climate change. Average temperatures have been climbing in Glasgow, as they have in the rest of the UK, and this has caused a huge increase in the number of slugs and snails. The life cycle of the French heartworm involves a development stage within slugs and snails and it is most likely that the dog had swallowed a slug infected with the parasite or eaten grass with a fresh slug trail on it.

The diagnosis was confirmed by Professor John Gilleard from the University’s Faculty of Veterinary Medicine who said: “We found the larvae in the faeces and after running some specialised PCR tests confirmed it was the French heartworm parasite. The dog had never left Glasgow so it had to have come into contact with the parasite here."

Source: University of Glasgow