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Heartworm disease is something that most dog owners think will never happen to their dog until the unlikely happens. Heartworm is carried by mosquitoes. Mosquitoes are most prevalent from spring through fall, but they continue to be active throughout the year. Dogs are more susceptible to the disease, though it has been on the increase among cats.

Learn more about heartworm in dogs so that you can help prevent this serious, costly illness from occurring. It is far easier and less expensive to prevent than it is to treat. The team at Westarbor Animal Hospital is here to give you the awareness, education, and steps to prevent this preventable disease.

Heartworm Disease in Dogs

A blood-borne parasite called Dirofilaria immitis causes heartworm (also called dirofilariasis). Mosquitos carry the parasite and transmit it through their bite.

The Cycle

The life cycle of heartworms begins with the tiny microfilariae that live in the mosquito. These minuscule heartworms develop into larvae within one week to 30 days and then the mosquito passes them through its bite to a warm-blooded host. At this stage, they move into their host’s heart and lungs, developing into mature heartworms that reproduce and continue the cycle.

Heartworm in dogs can only be transmitted through the mosquito. An infected dog cannot pass it to another dog.

Symptoms of Heartworm Disease

Symptoms are slow to show in most dogs and sometimes don’t show in cats at all until too late. Heartworms in dogs must mature and reproduce to show signs of their presence. After a dog is infected, it can take up to 6 months for them to develop clinical signs of infection. By then, heartworms are mature and causing damage to the heart.

Symptoms include:

  • Persistent cough
  • Easily tired
  • Lack of interest in exercise
  • Weight loss/decreased appetite
  • Bloated abdomen
  • Labored breathing

As the heart and lungs become more impacted by the heartworms, more serious signs can occur, such as bloody stool, pale gums, and eventual collapse. This cardiovascular distress can be fatal if not treated. Diagnosis and treatment can be costly and painful. Surgery is often needed to remove the mature heartworms from the cardiovascular system.

Heartworm in cats is complex and rarely produces signs until it is an emergency. Many cats seem fine until they collapse.

Should I Worry About My Dog?

It would be nice if heartworm disease was rare, but we are seeing an increase in diagnoses due to unseasonably warm winters and wet springs. This combination allows mosquitoes to thrive. Heartworm is in all 50 states and globally. It only takes one bite to transmit the disease (and mosquitoes do get inside the house to bite inside pets). That is why your best, safest, and most effective course of action is to keep your dog (or cat) on a heartworm preventative.

At Westarbor, we offer convenient, effective products for your pet’s parasite prevention needs. We recommend easy-to-administer monthly chewables like Heartgard Plus and Sentinal Spectrum prescriptions capable of real protection.

For your pet’s safety, we also recommend annual heartworm testing and require heartworm testing before the start of any heartworm medication. Heartworm preventatives, given to a dog that already has heartworms, will kill immature heartworms in the bloodstream, possibly producing anaphylactic shock and death. Preventatives won’t kill mature heartworms. Without testing, you could be risking your dog’s life and not addressing the mature heartworms causing heart damage.

Would you like more information about heartworm in dogs? We are here to answer your questions and welcome you to schedule your pet’s wellness examination. Please call us!

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