Heartworms are classified as a kind of worm similar to roundworms. In fact, they look a bit like roundworms. Adult heartworms in the heart of an infected animal lay very tiny larvae called microfilariae, which then live in the bloodstream. These microfilariae enter a mosquito when it sucks blood from an infected animal. In two to three weeks, the microfilariae develop into larger larvae in the mosquito and migrate to the mosquito’s mouth. Therefore, the only way that heartworms can occur in dogs is when a dog is bitten by an infected mosquito. It actually takes about seven months after the dog is bitten by an infected mosquito for the larvae to mature into adult heartworms. Afterwards, they reside in the heart, lungs, and surrounding blood vessels of the bitten dog, hence, they begin reproducing. Adult worms can grow up to 14 inches in length and can live for about five to seven years in the dog’s bloodstream.

It is also important to note that it can only be passed on by mosquitoes. This is because it’s a specific parasite that only affects dogs, cats, ferrets and other mammals. In dogs, the adult worms can obstruct the various large blood vessels leading from the heart to the lungs. Worms may also enter smaller vessels in the lung and obstruct those vessels, as well. In severe cases, these deadly worms can start to fill the right ventricle of the heart, causing heavy breathing in dogs and even heart failure. So in order to prevent this to happen to your dogs, here are some ways that can help you determine if your dog is suffering from heartworms:

• Coughing can be a sign of heartworms. Observe your dog if he is having frequent coughs and is experiencing heaving coughing as well. If you have already taken him to the vet several times and the cough may not seem to subside despite any basic medication, it may be best to have laboratory testing to check on heartworms.
• Easily fatigued even on very minimal physical activity can be a sign of heartworms in dogs.
• Sudden loss of appetite can be a potential sign for heartworms, so never ignore this aspect.
• Difficulty or heavy breathing can be a great sign of heartworms in dogs. This is because these worms can obstruct the smooth blood flow in your dog’s heart, causing it to have difficulty in breathing.

Once you see these signs in your dogs, take your dog to a vet to perform laboratory testing. It will also be best if a yearly blood testing is done to detect heartworms that are in early stages. Not only can you save your dog from a very deadly disease, you can also save some money in terms of medications.

[The next article is about how to prevent heartworms in dogs.]