Recent changes have raised our concern about heartworm disease in cats: 1) increased adoption of heartworm positive dogs from the southern US, 2) White Nose Syndrome decimating the bat population that feeds on mosquitoes, and 3) the fact that heartworm disease in cats can be acutely fatal.

Important facts about heartworm in cats:
Infection can cause acute respiratory distress or death.
Infection can cause asthma or chronic bronchitis; some cats show no signs.
Heartworm disease is much less common in cats than dogs, but when it occurs the results can be devastating.
A heartworm test is not required before beginning a preventative. Unlike dogs, cats do not develop microfilaria so there is no risk of a reaction to the medication if your cat is heartworm positive.
In numerous studies across the US it has been repeatedly shown that twenty five percent of heartworm positive cats are indoors.
While testing for heartworm is not necessary before starting any preventative, we do recommend testing symptomatic cats or if we want to know about past exposure.
Unlike dogs, there is no specific treatment for heartworm if your cat becomes infected.

Preventative options for cats:
Interceptor, a pill given once monthly in a chewable form. In addition to preventing heartworm this medication prevents roundworms and hookworms, important zoonotic diseases (spread to children)
Revolution, a topical applied once monthly. Revolution also prevents fleas, roundworms, hookworms, and ear mites.
Neither Interceptor nor Revolution will prevent ticks. If you have concerns about ticks you can use either product with Frontline by giving one on the first of the month, and the other on the 15th.

Important zoonotic information:
Roundworms and hookworms can be transmitted to children. Signs in children range from a local skin irritation to severe liver disease. The CDC recommends year round deworming in cats (and dogs) to prevent infections in children.