Most pet owners have heard of heartworm disease and know that it is transmitted by those annoying mosquitoes, but not everyone understands the seriousness of the disease and how important reliable prevention is.
Heartworm disease is indeed transmitted by mosquitoes. A mosquito bites an animal that has heartworm disease such as an infected dog, cat, coyote, fox, raccoon or opossum, and ingests heartworm microfilaria. The infected mosquito then bites your dog or cat transmitting the microfilaria. In dogs, the microfiliaria travel to the heart chamber and mature into adult worms. In cats, the worms often do not mature, however can still cause serious problems including sudden death. You may assume that if your cat stays indoors, it’s safe from heartworm disease, however it’s estimated that 30% of heartworm positive cats are indoor only. Although there is a reliable test for heartworm disease for dogs, there is not one for cats.
The scary thing is that positive heartworm cases are increasing. Within the last 4 years there has been more than a 20% increase in positive heartworm cases nationwide. This is due to several factors. First, more rain and humidity in recent years provide an ideal environment for mosquitoes. Second, more and more dogs and cats are being transported from the South where heartworm disease is prevalent. Hurricanes and other natural disasters have displaced thousands of pets in the South and larger than ever numbers are being transported to other states. Heartworm disease takes 6 months from time of transmission until it will show on tests, so testing before transport is not always effective.
The good news is that heartworm disease is easy to prevent. There are several very effective heartworm preventative products available for both dogs and cats. These also have the added benefit of protecting against common intestinal parasites. For preventatives to offer the best protection, they need to be given once a month, year round. Any lapses in giving monthly preventative can cause breaks in protection and increase the risk of heartworm disease. We have seen cases where only 1 or 2 doses have been missed and infection has occurred.
Treatment for heartworm disease is both complicated and expensive. While there are approved treatments for dogs, there are none for cats. Each case is different and treatment plans need to be tailored to the individual depending on symptoms, severity and other factors. Even with successful treatment, lasting damage can remain.
Yearly heartworm testing for dogs and monthly, year round preventative for both dogs and cats is the best way to make sure that you never have to deal with this serious and potentially fatal disease.