Feline heartworm disease is more prevalent than we once thought.
Studies have shown that feline heartworm infection rates likely meet or surpass
infection rates for feline leukemia. Additionally, other data have suggested that the feline adult heartworm infection rate can be
estimated to be 20% of the canine infection rate for the same geographic area.
Although prevalence studies are ongoing, current research suggests that more cats are at risk than previously thought.
What is HARD?
Heartworm-associated respiratory disease, or HARD, refers to
the presentation and clinical circumstances associated with the death of
immature adult heartworms (so-called fifth-stage larvae) or the presence of adult worms in the pulmonary arteries of heartworm-infected
Is feline heartworm disease really that dangerous?
Feline heartworm disease is potentially more dangerous than its
canine counterpart for two critical reasons. First, diagnosis is complicated
and findings can be inconsistent. A heartworm-infected cat may present with
severe respiratory signs but test negative on antigen and antibody tests.
Ancillary tests such as thoracic
radiography, serum chemistry analysis, and echocardiography can
also be inconclusive. Cats can also die suddenly with no evidence of
preexisting illness. Second, there is no approved treatment for feline
heartworm disease, so the only way to protect feline patients is to initiate
year round heartworm prevention early in life.
All cats, even “indoor cats,” should be on prevention.