Heartworm Disease is Spreading

Heartworm disease in cats and dogs is spreading fast. No longer the preserve of mosquito infested swamplands we all now need to consider this very real threat to the health of our pets.

Until around a century ago heartworm disease was unknown. Then it was recognised in canines both in the wild and domesticated. Some twenty years later cat heartworm disease was first reported. As the organism must reside inside a female mosquito during part of its life-cycle the disease was believed only to affect animals residing in areas with dense mosquito populations. Sadly heartworm is no longer the preserve of mosquito ridden swamp land at all.

All 50 states of the United States report incidences of heartworm disease amongst the canine population. Much of that land is dry, arid and pretty mosquito free. But, mosquitoes are opportunistic pests and even though a region may have only a small population there will be hot-spots where mosquitoes thrive in concentrated numbers.

The Heartworm Society has carried out surveys into the incidences of heartworm disease across the United States over the last decade. From 2001 to 2007 (when the most recent figures are available) numbers of cases reported have grown significantly. Perhaps more worrying is that the figures show heartworm disease occurring all over the country.

The most concentrated regions for the organism to thrive and infect mammals occur around river deltas and the Gulf coast. This is what we would expect as these areas have huge mosquito populations, many of which are active year round. But the area of concentration for the problem is moving outwards. Whether this is a result of weather pattern change or mosquito adaptability is unknown. What is known is that the disease is spreading out from those original 'hot-spots'.

The problem is not all heartworm disease cases are reported. In fact many are not even diagnosed as the disease may not manifest itself with any visible symptoms until a pet suddenly dies. Then, of course not many animals are taken for an examination to determine the cause of death. Therefore, the true number of animals infected with the disease will never be known.

In Europe too, the problem is growing. Once the preserve of sunny Mediterranean regions heartworm is spreading north and eastwards. Although officially not recognised as a problem in the United Kingdom there is already anecdotal evidence of dogs suffering with the parasite particularly along the warmer South-East coast. There is a good chance that the problem will grow in the UK as mosquitoes are becoming more common for longer each year. Plus, more pets are now taken overseas to high risk areas, due to the introduction of pet passports. Where previously animals would be quarantined for six months after any overseas trip, now they enter the country easily. These international jet-setting pets bring the disease in, infecting mosquitoes who in turn can infect the local population.

Any responsible pet owner should check the risks of heartworm disease in their area. With treatment being difficult, unreliable, dangerous and expensive prevention is a much better, cheaper and safer option.

For more information about dog heartworm and heartworm meds visit the Heartworm, Dogs & Cats website. (heartwormsdogsandcats.blogspot.com)