Transmitted by mosquitos, these parasites can cause serious illness and even death, so precautions should be taken for any dogs who leave the UK. Heartworms, called Dirofilaria immitis, are very thin, thread-worms that can reach up to 30cm in length. You won’t see these worms yourself though, as they live within the right side of the heart, and the main artery leading from the heart to the lungs.
Heartworms are nasty, and thankfully are not found in the UK. They are transmitted by mosquitos, and are therefore found in warmer countries, such as those in southern Europe.
Heartworms reproduce by producing tiny offspring, called microfilaria. These travel around the blood of infected dogs, and are ingested by mosquitoes when they bite and feed. These microfilaria can then live within the mosquito, and be passed on to the next dog that the mosquito feeds on.
The maturation process for heartworm is slow, and it can take six months for the worms to even reach the heart after an infection starts. The slow progression of this infection means that even dogs who have not travelled for some time should still be considered as ‘at risk’ of developing heartworm unless they have had appropriate parasite treatments.