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Parasite control is important in cats of all ages. Prevention includes both animal and environmental control. The Companion Animal Parasite Council (CAPC) guidelines contain recommendations about prevention of ecto- and endoparasites, fecal testing, and more.20The United States Centers for Disease Control and Prevention also provides information on a variety of zoonoses. Items for discussion are listed in Table 1, and a few specifics are expanded on below.

Heartworm: Key Points
  • Although the incidence in cats is lower than it is in dogs (10–15% of the rate in dogs), both indoor and outdoor cats are at risk of heartworm infection.
  • Infection with even a small number of adult worms can cause severe disease.
  • Signs differ from those in dogs, tending to be nonspecific.
  • A combination of antigen and antibody testing increases the probability of an accurate diagnosis.
  • Adulticide treatment is currently not recommended for cats. There is no evidence that it improves survival in infected cats, and the death of adult worms can be life-threatening.
  • Monthly prophylaxis is both safe and effective. Some heartworm preventives also provide control of other parasites.


  • Because prenatal infection does not occur in kittens, roundworm treatment given every 2 weeks can start at 3 weeks of age. Kittens may begin receiving a monthly general endoparasite preventive at 8–9 weeks of age.20

All life stages

  • Feces testing allows monitoring of compliance with preventive medication as well as diagnosis of some endoparasites not treated by broad-spectrum preventives.
  • Heartworm presents a risk at all life stages in endemic areas.52 Some points of note are listed in the adjacent box; additional details may be found on the websites of the CAPC and American Heartworm Society.