Head of the Class Dog Training LLC 

Winchester, VA

Winchester's Premium Professional Pet Training

Quiz: How Much Do You Know About Heartworms?

Heartworms can be devastating to your dog’s or cat’s health, so we thought it would be a good idea for you to test your understanding of this disease. Are you ready? Take the true/false quiz below to see how much you know about heartworms.


  1. Heartworms are contagious from dogs to humans.
  2. Heartworms do not exist in some areas of the U.S. like desert areas, Arizona, California and Oregon.
  3. Dogs cannot pass heartworms to other dogs.  
  4. Adult heartworms can be up to 12 inches long and can live 5 to 7 years.
  5. Symptoms of heartworms in cats are always very dramatic.
  6. Symptoms of heartworms in dogs are reluctance to exercise, being easily fatigued, mild cough, decreased appetite and weight loss.
  7. The test for heartworms is a urine screening.
  8. Vets recommend testing your dog annually for heartworms, even if your dog is on heartworm prevention medication.
  9. Early detection of heartworms improves your pet’s chances of recovery.
  10. Heartworm medication is available without a prescription.
  11. There is a vaccine to prevent heartworm disease.
  12. You should not adopt an animal with heartworm disease.
  13. If your dog is being treated for heartworms, it’s important to restrict activity during the recovery period.
  14. You can skip heartworm treatment during the winter because mosquitos are not a problem in the cold.


  1. False. Heartworms can only be spread from the bite of an infected mosquito. They can affect dogs, cats, ferrets and other mammals, and very rarely can infect humans (but they cannot complete their life cycle in humans).
  2. False. Though in the past heartworm was not prevalent in these areas, mosquitos are now able to live in these areas due to irrigation and development.
  3. True. Mosquitos are the only transmitters of heartworm.
  4. True. Adult heartworms are big and, well, hearty.
  5. False. Symptoms of heartworms in cats can be very subtle or dramatic and include asthma-like attacks, coughing, vomiting, decreased appetite or weight loss.
  6. True. However, these symptoms are not always seen together.
  7. False. Heartworms are detected through a blood test.
  8. True. No preventative medicine is 100% guaranteed.
  9. True. Heartworms do not have to result in the infected animal’s death.
  10. False. All heartworm prevention medications require a vet’s prescription.
  11. False. There is currently no vaccine available to prevent heartworm disease. However, scientists are investigating this option for the future.
  12. False. If you are willing to treat the disease right away, it’s completely fine to adopt an animal with heartworms. It is very common for shelter animals to have heartworms and you will be saving the animal’s life by adopting and giving the proper medical care that the shelter can likely not afford to give.
  13. True. Immediately following treatment the worms begin to die and break into pieces. If dogs are permitted to exercise, pieces of the broken worms can cause a blockage in the pulmonary vessels and kill the dog.
  14. False. The American Heartworm Society recommends treating your pet year-round. They recommend this because there is a common problem with people forgetting a dose, so using prevention year round will allow your dog to be protected even if you miss a month.

How did you do? Do you feel confident in your understanding of heartworms and how to prevent them? If not, speak to your vet. Prevention is key to keeping your pets safe and healthy.

Lisa Marino, CPDT-KA, KPA-CTP, PMCT, has taken her varied teaching experiences and applied them to helping owners understand and train their beloved four-legged family members. She has more than four years’ experience leading group dog training classes at Best Paw Forward in Hartland, WI, and opened Head of the Class Dog Training LLC in Winchester, VA in 2012, where she conducts group classes and private lessons, as well as helps owners to modify their dogs' problem behaviors.

Lisa earned her CPDT-KA in 2012, is a 2015 graduate of the prestigious Karen Pryor Academy and is a Pat Miller Certified Trainer.

She has 4 registered therapy dogs and is a Pet Partner Therapy Team Evaluator and a member of HOPE AACR. As a former middle school teacher, she works well with families and children and does school presentations on various dog related topics.