Heartworm. The word itself does not sound good, which is appropriate, because although heartworm disease is common, it can be fatal if left untreated. The best way to avoid heartworms is to understand the disease, burst the common misconceptions that surround the illness, and to protect your pet. Here are some questions and answers to help.

Question: What are heartworms?
Answer: Heartworms are a parasite transmitted from infected mosquitoes to animals.

Q: Can people get heartworms?
A: Humans are rarely infected by heartworms, which typically infect only dogs, cats, ferrets, coyotes, wolves, and foxes. Ferrets, because they are small, are especially sensitive to heartworms—a few worms can significantly impact their health. 

Q: Is heartworm disease fatal?
A: If untreated, heartworm disease is usually fatal. The worms can reach up to a foot long and a medium-size dog can host up to a hundred worms. Typical causes of death are respiratory distress and heart failure from the strain the heartworms put on the heart, lungs, and surrounding blood vessels.  

Q: What are the signs of heartworm disease?
A: Many pets show only mild heartworm disease signs, which often are easily overlooked. Coughing, fatigue, struggling to exercise, weight loss, and loss of appetite are common heartworm disease signs, but they may also be attributed to other diseases. Some pets may show no signs at all, but they will die suddenly. Don’t rely on your ability to recognize the disease signs in enough time to save your pet. Instead, rely on preventive medication and annual testing to confirm you’re doing everything you can for your pet.

Q: What is the treatment for heartworm disease?
A: Treatment for heartworm-positive dogs is intensive, depending on the seriousness of the infection, but is manageable for most dogs and owners. Treatment includes a course of antibiotics and regular injections to kill adult heartworms, coupled with exercise restriction to limit the possibility of dead worms working their way into the lungs and causing an obstruction. Surgery may be required for extreme infections. Outcomes vary depending on length of infection, immune response, the pet’s age and condition, and number of worms present. Unfortunately, no treatment options currently exist for heartworm-positive cats, and preventive medication is the only way to keep them safe.

Q: Can heartworm be prevented?
A: Heartworm is 100% clinically preventable with medication prescribed by our veterinary team. If the medication is administered on time and at the correct dosage based on weight, your pet likely will avoid heartworm infection. Dogs and cats—even cats who stay indoors—should receive regular, year-round heartworm preventive medication.

Q: Is heartworm-preventive medication expensive?
A:  Heartworm preventive medication is much less expensive than treating the disease. The cost of heartworm preventives is dependent on a pet’s size and the specific medication chosen. 

Q: Can I give heartworm preventive half the year? What if I live in a northern state?
A: No. The old theory that giving preventive medication only in the summer months was adequate has been disproven. Pets are also at risk for heartworm disease in winter, including in northern states—the risk is lower, but it still exists, and heartworm infection is diagnosed in all 50 states every year. 

Q: What if my pet has skipped a dose of preventive medicine, or has never had it?
A: Call us to schedule an appointment for a heartworm test. The American Heartworm Society recommends yearly heartworm testing for all dogs over 7 months of age. One missed or late dose of preventive can result in heartworm disease. After your pet’s initial test, she will need a second test six months later to check for mature larvae. Dogs on a year-round dose of preventive should be tested yearly, as well, because of the risk of medication-resistant heartworms, or dosage issues.

Q: Doesn’t a negative test result mean my pet is healthy?
A: Unfortunately, despite a negative test result, your pet may still have a heartworm infection. The most commonly used test can only detect adult female worms, so if your pet is carrying immature female worms, a small number of worms, or only male worms, she will test negative. This emphasizes the need to test your pet again at six months if she is just starting on heartworm medication, or has missed or delayed a dose of preventive. 

Our pets are always at serious risk for heartworm disease, but, fortunately, evidence shows that a clear understanding of the disease and diligent prevention are key to keeping our beloved pets safe. Contact our office to make an appointment for heartworm screening and to get the preventive medication your pet needs to stay disease-free.