Average Life Span
Rates of Infection
Microfilariae
Indoor Cats
How Many Cats Have Heartworm?
- Cats infected with heartworm that goes untreated generally only live for two to three years from the onset of the disease. The cat's body tries to stop the heartworm from traveling through the system, but in doing so, cysts often form in the brain, kidney, liver and other organs. Therefore, in addition to heart failure, heartworm can also cause problems in the organs such as kidney and liver failure, seizures and sudden, unexplained death.
- Cats exposed to heartworm have a 60 percent to 90 percent chance of contracting the disease. That statistic is certainly alarming, especially for cats that roam outdoors or are in frequent contact with other cats whose medical history is unknown. However, this is an instance where cats are luckier than dogs. Almost 100 percent of the time that a dog comes into contact with heartworm, it winds up contracting the disease.
- Microfilariae, or first-stage larvae, are the offspring of heartworms. Heartworms do not lay eggs like other bugs and instead give live birth to these creatures. Therefore, the population of heartworms is able to rapidly grow and take over once they start giving birth. However, in cats with heartworm, only 20 percent of them are found to have microfilariae in their blood. Although heartworm is not good news in general, at least the bugs are not quickly reproducing in the majority of felines.
- It is widely believed that indoor cats are not susceptible to heartworm. However, that is not the case. In fact, a North Carolina State University study found that 25 percent of cats infected with heartworm are solely indoor cats, which means that they do not go outside at all. It is important to remember that the statistics do not mean that the other 75 percent are solely outdoor cats, but comprise both outdoor-only and indoor/outdoor cats.
- Determining the number of cats that have heartworm is difficult because answers vary by region. Generally if there are more mosquitos, the rate of heartworm is higher. Tulsa, Oklahoma, reported a 26 percent rate of heartworm in cats, while southwestern Texas reported a 9 percent rate. It was long thought that approximately one in five cats were infected; however, neither of the aforementioned statistics completely agree with that number. More research needs to be conducted in order to fully answer the question.
