Dogs and puppies are at risk to various sorts of parasites. Parasites are tiny creatures that mainly feed on animal's blood. There are two types of parasites: internal parasites and external parasites.
However, parasite like heartworm comes from mosquito bites. An adult heartworm lives in the heart and vessels of the dog and apparently produces hundreds young heartworms. The carriers of these parasites are mosquitoes and from the mosquitoes' bite the parasites are easily transfer to other uninfected dogs.
Imagine that these parasites are on your precious dog and they even live and feed at the expense of your dog.
To ensure that your dog is free from heartworm parasites, preventive medication should be given especially in the early months of the dog to avoid such problem on the dog's health.
Most medicine for heartworm is a beef-flavored-chewable tablet given to dogs through ingestion once in every month to ensure protection.
Most medicine available for curing heartworm comes in different colors and categorized to the weight and months of the dog. For example if your dog weighs 25 lbs or up and age six months old, your veterinarian is more likely give you the blue one for six-month-old dogs.
When your dog gets older and heavier, the next medication would be different from the previous one. Hence, the quantity to be ingested by your dog is based on their weight and age. This applies on most medicine available in the market for heartworm.