Mosquitoes transmit heartworms, and pets in all 50 U.S. states have been affected. While infection rates vary depending on weather patterns and annual mosquito populations, the risk is always present. Although this disease is entirely preventable, many heartworm-infected pets die every year with or without treatment. Read our Valley Center Veterinary Clinic team’s disease facts to learn how to prevent your pet from contracting this serious condition.

#1: All pets have a heartworm infection risk

Mosquitoes are the vector for heartworm infection transmission. These insects ingest immature larvae from the blood of infected pets or wildlife reservoirs, and can transmit the larvae in their infective stage to another host several weeks later. The heartworm disease incidence rate is highest in the warm, humid southern states that experience high mosquito activity, but the condition has been diagnosed in pets throughout the United States. 

Check this incidence map to see the number of cases that occurred in your area last year. Keep in mind that this map does not directly correlate to your pet’s infection risk. Only one infected pet or another animal, such as a coyote or fox, in your neighborhood drastically increases your pet’s infection risk. Your indoor pet is also at risk, because mosquitoes can easily sneak into your home. One in four infected cats has never gone outdoors.

#2: Heartworm infections affect cats and dogs differently

Dogs are heartworms’ preferred host, meaning worms thrive inside the canine body and reproduce, often numbering from 30 to more than 100. The worms live in a dog’s heart, lungs, and nearby blood vessels, causing inflammation and permanent damage. Dogs’ signs do not appear until the infection has been present for months to years, and include coughing, exercise intolerance, or in advanced cases, heart failure.

Cats, on the other hand, are not preferred heartworm hosts. Larvae cannot usually survive cats’ innate immune defenses. However, some cats are susceptible to infection, and one to three worms may survive to adulthood. Although these worms cannot reproduce, they can still be life-threatening. Cats with heartworm infections may have no detectable signs, show asthma-like respiratory problems or vague illness signs such as vomiting and weight loss, or die suddenly without warning.

#3: Pet heartworm prevention is highly effective when administered correctly

Your pet’s heartworm prevention is an affordable, effective option to prevent immature larvae from maturing into adults, thereby preventing infection. You must consistently administer your pet’s preventive product year-round, as a lapse of only two or three months is plenty of time for an infection to develop. 

Considering that heartworm treatment is costly and risky, this condition’s prevention is most pets’ safest, best option. Ask our team for information about preventive products and the one that would be best for your pet’s needs. All pets must undergo heartworm testing before starting a new preventive regimen, because an infected pet who abruptly starts a preventive product could have an adverse reaction.

#4: Routine heartworm testing identifies pets’ infections in the early stages

Our Valley Center Veterinary Clinic team recommends routine annual heartworm screening for dogs, which helps us identify silent infections before too much damage has occurred, and initiate treatment to prevent the disease from causing additional heart disease or failure. The test requires only a small blood sample, and we can perform this diagnostic during your pet’s annual visit. Cats should be tested before starting a new preventive, after a lapse in preventive administration, or if we suspect they have a heartworm infection.

#5: Heartworm infections are treatable in dogs but not in cats

Feline heartworm prevention is crucial, because safe treatment options don’t exist for this species. Infected cats experiencing symptoms can be treated with supportive care and medications, but the worms must live out their natural lives and may cause severe complications during that time.

Dogs’ heartworm treatments are available, but they aren’t a walk in the park. Our team strongly recommends prevention medication, because treatment is costly, requires painful muscle injections, and can lead to adverse and sometimes life-threatening reactions as the worms die and overwhelm the dog’s body with toxins. During treatment, which usually lasts several months, you must ensure your dog fully rests to prevent their heart rate from increasing, which could lead to further complications. 

Consider these heartworm disease facts, and follow our tips to help prevent your pet from contracting this deadly but preventable disease. Schedule your pet’s next wellness visit, heartworm test, and heartworm prevention consultation with our Valley Center Veterinary Clinic team.