FAQs/Heartwm.htm

Question 5: My dog/cat hardly ever goes outside. Does he/she really need heartworm testing and prevention?

Answer: The short answer is YES. The long answer is... Heartworm disease is caused by the blood parasite Dirofiliaria immitis. An immature form of the parasite is transmitted by mosquitoes from an infected animal to an uninfected animal. Both dogs and cats can be affected. Heartworm disease is endemic in our area, meaning that there are enough unprotected infected dogs to continually maintain the disease. Since heartworm is transmitted by mosquitoes, any dog or cat exposed to mosquitoes is at risk of contracting the disease. Therefore even "indoor" pets are at risk of heartworm disease since mosquitoes can enter our homes and since most dogs and some cats go outside to urinate, defecate, play, walk, etc. Current heartworm tests for dogs indicate whether or nor a dog was exposed six months or longer ago. Therefore, we recommend first testing dogs when they are between eight and nine months of age AND if they were born during heartworm season. If one of these requirements is not met the pet should be put on heartworm prevention and tested at an appropriate time. We recommend that all dogs be tested regularly for heartworm disease. There is currently no test for heartworm disease in cats that we recommend on a regular, screening basis. The frequency of the recommended testing depends on which preventative you chose to use. For more information, check out the website for The American Heartworm Society . The two heartworm prevention products we offer are Heartgard Plus/Heartgard and Revolution. Recently, ProHeart6, a third heartworm prevention option, was recalled due to reports of possible adverse reactions. See FAQ Number 18 for more information. The manufacturers' websites can be visited through our Links page. The specifics of the three products are summarized in the table below, where D = dogs and C = cats:

Product	Heartgard Plus (D) Heartgard (C)	ProHeart 6 RECALLED	Revolution
Active ingredient	Ivermectin/Pyrantel (D) Ivermectin (C)	Moxidectin	Selamectin
Used in which species?	Dogs and Cats	Dogs only	Dogs and Cats
Means of administration	chewable tablet (at home)	injection (at clinic)	topical (at home)
Frequency of administration	monthly	every 6 months	monthly
Period of administration	8 months (May - December)	year round	8 months (May - December)
Frequency of testing	annually	first and second years, then every other year	annually
Age at which can first be given	6 weeks for puppies and kittens	6 months for puppies only, not recommend for kittens	6 weeks for puppies and kittens
Safe for pregnant or lactating animals?	yes	yes	yes
Other parasites affected	D: hookworms, roundworms C: hookworms	D: hookworms	D: sarcoptic mange mites, fleas, ear mites, American dog tick C: fleas, ear mites, hookworms, roundworms
Safe for Collies and other Ivermectin-sensitive breeds?	yes	yes	yes
Safe for heartworm positive dogs?	probably, but not labeled for such use	probably, but not recommended	probably, but not recommended