According to the Companion Animal Parasite Council’s parasite prevalence maps, Kentucky pets have a significant heartworm disease risk, which can severely damage their heart and lungs. Our Central Kentucky Veterinary Center team wants to help ensure these dangerous parasites do not affect your pet, and we provide tips to help you protect your four-legged friend from this potentially life-threatening infection.

#1: Know how heartworms are transmitted to pets

An important part of the heartworm life cycle, mosquitoes transmit these parasites to pets. When a mosquito takes a blood meal from a pet or animal infected with baby heartworms (i.e. microfilariae), the bug ingests the parasites. Once inside the mosquito, the microfilariae take two to three weeks to mature to an infective stage. During the mosquito’s next meal, the bug can transmit the infection to a vulnerable pet. Once inside your pet, the heartworm larvae mature for several days in the body tissues before finding their way to your pet’s heart, lungs, and associated vasculature.

#2: Understand heartworm infection dangers to pets

Unlike other parasites, such as roundworms and tapeworms, which don’t typically cause serious illness in pets, heartworms can cause severe damage to your four-legged friend’s heart and lungs. Heartworms affect dogs and cats differently:

  • Vascular disease in dogs — A dog is a natural heartworm host, and the parasites thrive inside the canine heart, maturing to adulthood, mating, and producing microfilariae. Heartworm disease inflames the blood vessels supplying a dog’s lungs, causing their heart to struggle to pump blood through the high tension area, eventually leading to congestive heart failure (CHF). In addition, because dogs are natural hosts, numerous worms can accumulate in their heart, leading to caval syndrome, which prevents blood flow.
  • Lung disease in cats — Cats are atypical heartworm hosts, and when these parasites enter your feline friend’s body, their immune system responds strongly—killing many heartworms before they reach adulthood. However, immature larvae can significantly affect a cat’s health. When the parasites reach a cat’s lung vasculature, severe inflammation occurs, causing heartworm-associated respiratory disease (HARD). While most parasites don’t reach adulthood, only one or two adult heartworms can block blood flow in the tiny feline heart.

#3: Recognize heartworm disease in pets

Most pet owners usually can’t recognize when their furry pal’s heartworm disease is in the early stage, because most pets don’t exhibit signs until the infection is advanced. Keep an eye out for these signs, which indicate your pet’s condition has progressed:

  • Dogs’ signs — Dogs’ heartworm disease signs include lethargy, decreased exercise tolerance, persistent cough, and weight loss. Once your dog develops CHF, they may experience abdominal fluid accumulation, causing a pot-bellied appearance. Dogs who have caval syndrome typically collapse suddenly and have difficulty breathing.
  • Cats’ signs — Cats’ heartworm disease signs mimic feline asthma and include wheezing, open-mouthed breathing, increased respiratory rate and effort, and vomiting. In many cases, a cat’s first disease sign is sudden death.

#4: Have your pet tested every year for heartworm disease

According to the American Heartworm Society (AHS), dogs should be tested for heartworms once a year. When diagnosing heartworms, testing options include:

  • Antigen testing — Veterinarians commonly use this test as a dog’s annual heartworm screening. An antigen test detects a protein the female heartworm produces.
  • Microfilariae testing — The AHS also recommends including a microfilariae test in conjunction with an antigen test to screen dogs annually. This test indicates microfilariae in a pet’s bloodstream.
  • Antibody testing — Cats typically don’t have female heartworms or microfilariae.  However, an antibody test detects a pet’s response to the heartworm infection, and veterinarians often use it in conjunction with an antigen test when determining whether a cat has the disease. 
  • X-rays — Heartworms cause changes to a pet’s heart, lungs, and surrounding vasculature. Your veterinarian can observe these changes on a chest X-ray.
  • Ultrasound — Veterinarians often use ultrasound to assess the damage the disease has caused to a pet’s heart, and in some cases, to visualize the worms.

#5: Provide year-round heartworm prevention to your pet

The best way to protect your four-legged friend is to provide year-round heartworm prevention. Avoid being tempted to discontinue your pet’s treatment during the winter, because during an unseasonably warm day, mosquitoes can become active, putting your pet at risk. In addition, peak mosquito season varies from year to year, and you may stop your pet’s medication too soon or miss restarting the preventive soon enough to protect your furry pal from infection. Many heartworm preventive options are convenient, including:

  • Chewables — Some products come in tasty chewable treats that you should administer to your pet once a month. Always ensure your pet doesn’t spit out the chewable, because even one missed dose makes them susceptible to infection.
  • Spot-on treatments — If your pet is a picky eater, no worries. Some preventive products are available as a monthly spot-on treatment. 
  • Injectables — If you cannot administer your pet’s monthly preventive, our Central Kentucky Veterinary Center team can administer an injectable medication every 6 to 12 months to ensure your pet receives the protection they need.

If you choose to administer your pet’s heartworm prevention on a monthly basis, set a phone alert or mark your calendar. This strategy helps you remember to administer the preventive medication, because missing a single dose can put your furry pal at risk for infection.

#6: Decrease the mosquito population to help lower your pet’s infection risk

In addition to ensuring your pet receives year-round parasite preventives, you can help lower your pet’s heartworm disease risk by decreasing the mosquito population around your home. Follow these tips:

  • Maintain fly screens on your windows, doors, vents, and chimneys.
  • Keep unscreened doors and windows closed.
  • Run the air-conditioning when possible.
  • Remove water containers, such as tires, birdbaths, flowerpot saucers, and buckets, from your yard. 
  • Regularly clean gutters and drains to ensure water runs freely, preventing stagnation.
  • Empty and refresh your pet’s water bowl once a day.
  • Maintain swimming pools regularly, keeping them well chlorinated. 
  • Cut your grass short.

Heartworm disease is a preventable parasitic infection. Follow these tips to help protect your pet from contracting this life-threatening condition. Schedule your pet’s annual heartworm test with our Central Kentucky Veterinary Center team.