Heartworm in Dogs in Malaysia: How Mosquitoes Spread It and How to Prevent It

Heartworm disease is caused by a parasitic worm (Dirofilaria immitis) that lives in the heart and large blood vessels of the lungs. It is spread by mosquitoes, so in a tropical country like Malaysia, every dog, including indoor dogs, is at risk all year round.

How heartworm spreads

A mosquito bites an infected dog and picks up tiny larvae. When it bites your dog, the larvae enter the skin and slowly travel to the heart, growing into worms up to 30 cm long over about six months. Many dogs show no signs for months or years while damage builds up.

Signs of heartworm disease

  • A soft, persistent cough
  • Tiring quickly on walks or reluctance to exercise
  • Weight loss and reduced appetite
  • Fast or difficult breathing
  • A swollen belly in advanced cases
  • Sudden collapse (an emergency)

Testing

Vets use a quick blood test that gives results in minutes. Testing is recommended before starting prevention in dogs older than about six months, and then regularly as your vet advises.

Prevention is simple and cheaper than treatment

Prevention options include the following. Many monthly products also cover intestinal worms, and some cover fleas and ticks too, so ask your vet which combination suits your dog.

  • Monthly chewable tablets or spot-on treatments prescribed by your vet
  • A yearly injectable preventive, available at some clinics
  • Give prevention every month, all year: there is no "off season" in Malaysia
  • Reduce mosquitoes: remove standing water from pots, drains and containers at home

If your dog tests positive

Heartworm treatment is possible but takes months and requires strict rest. Follow your vet's plan closely. Never start a preventive on a positive dog without your vet's guidance.

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Need a vet? Find a vet clinic near you anywhere in Malaysia.

FAQ

Can indoor dogs get heartworm?

Yes. Mosquitoes easily get inside homes and condos, so indoor dogs also need prevention in Malaysia.

At what age should puppies start heartworm prevention?

Most vets start prevention at around 8 weeks old. Your vet will advise the right product and dose for your puppy's weight.

Can cats get heartworm?

Yes, cats can be infected too, although it is less common. Ask your vet about prevention for cats in your home.