Heartworm is a potentially fatal disease.  It is transmitted by mosquitoes, an insect in abundant supply in Singapore.  Hence, all responsible dog parents give their dogs heartworm preventive drugs.

But before you give the drug to your dog, you MUST first bring the dog to the vet for a blood test.  It is only safe to consume the drug if the dog is tested negative.  If the dog is heartworm positive and he eats the drug, the dog might die as the heart is being clogged by a big lump of numerous dead heartworms.

Heartworm preventive medicine must be given continuously without gaps.  They come in daily, monthly (most common) and yearly forms.  Check with you good vet. 

Haven't read Misconceptions?  Read it now.