FOUR PAWS VETERINARY HOSPITAL
8401 Ranch Road 12 San Marcos, TX * Phone: (512) 396-7297 * Fax: (512) 392-7297
FELINE HEARTWORM DISEASE
Proactive prevention is that only sure way to protect cats.
THE FIVE MYTHS AND MISUNDERSTANDINGS ABOUT FELINE
HEARTWORM DISEASE REVEALED:

  1. DOGS VS. CATS: I thought that heartworm was mainly a dog's
    disease. Heartworm disease is not just a canine disease. Heartworms
    affect cats differently than dogs, but the disease they cause is equally
    serious.
  2. INDOOR VS. OUTDOOR CATS: But my cat stays indoors, so she's
    safe right? It only takes one mosquito to infect a cat, and because
    mosquitoes can get indoors, both indoor and outdoor cats are at risk and
    should receive heartworm preventive medication. In a North Carolina study,
    28% of the cats diagnosed with heartworm were indoor-only cats.
  3. IT'S A HEART DISEASE: How does it affect my cat? The name
    "heartworm disease" is a misnomer, as it mostly affects the lungs not just
    the heart. Signs are often mistaken for feline asthma, allergic bronchitis, or
    other respiratory diseases.
  4. ADULT HEARTWORMS VS. LARVAE: What if the heartworm larvae
    never develop into adult worms? Cats do not need an adult heartworm  to
    exhibit clinical signs: in fact, larvae are a main cause of the problems.
    Studies show that 50% of cats infected with heartworm larvae have
    significant disease of the small arteries supplying blood to the lungs.
  5. DIAGNOSIS: Is it easy to test whether my cat has heartworm
    disease? Diagnosis is difficult as negative antigen and antibody tests do not
    rule out heartworm disease. Positive tests, however, are significant.

CAN I TELL IF MY CAT HAS HEARTWORM?
SIGNS ASSOCIATED WITH HARD (HEARTWORM ASSOCIATED
RESPIRATORY DISEASE):
  • Anorexia
  • Blindness
  • Collapse
  • Convulsions
  • Coughing
  • Diarrhea
  • Difficulty breathing
  • Fainting
  • Lethargy
  • Rapid heart rate
  • Sudden Death
  • Vomiting
  • Weight loss

WHAT CAN I DO?
Heartworm disease is harmful, even fatal, but very preventable. Ask your
veterinarian for current recommendations regarding year-round, broad spectrum
heartworm preventives for your cat. Even if doses are accidentally skipped, by
giving preventives year-round the retroactive effectiveness is increased, and it is
possible to actually stop most worms from developing into adults.

  • How does a cat get heartworm?
Heartworm infection takes place when a mosquito carrying microscopic-size
heartworm larvae bites a cat. The larvae enter through the bite wound where they
develop in the tissues. The immature worms then enter a blood vessel and are
carried to the arteries in the lung where they cause an inflammatory reaction.
Most worms die at this stage, causing even more inflammation. The worms that
progress to the adult stage may live undetected for years. But, when the adult
worms die, the inflammation can be severe enough to cause death. The respiratory
signs associated with these reactions are called Heartworm Associated
Respiratory Disease (HARD).

  • What should I know about heartworms?
One study conducted in the Texas Gulf Coast region in the late 1990s revealed
heartworm antibodies were present in 26% of the cats examined, indicating the
cats were infected at some point in their lives. Adult worms were present in 10%.
The rate of heartworm infection was significantly higher than that of feline
leukemia virus infection at 5%, and feline immunodeficiency virus (feline AIDS)
infection at 6%.

The American Heartworm Society and the American Association of Feline
Practitioners have launched a joint campaign, funded by an educational grant from
Pfizer, to promote awareness of the serious danger of heartworm disease in cats
that reveals itself as HARD.